Nursing protects honeybee larvae from secondary metabolites of pollen

PubMed Central

Lucchetti, Matteo A.; Kilchenmann, Verena; Glauser, Gaetan; Praz, Christophe

2018-01-01

The pollen of many plants contains toxic secondary compounds, sometimes in concentrations higher than those found in the flowers or leaves. The ecological significance of these compounds remains unclear, and their impact on bees is largely unexplored. Here, we studied the impact of pyrrolizidine alkaloids (PAs) found in the pollen of Echium vulgare on honeybee adults and larvae. Echimidine, a PA present in E. vulgare pollen, was isolated and added to the honeybee diets in order to perform toxicity bioassays. While adult bees showed relatively high tolerance to PAs, larvae were much more sensitive. In contrast to other bees, the honeybee larval diet typically contains only traces of pollen and consists predominantly of hypopharyngeal and mandibular secretions produced by nurse bees, which feed on large quantities of pollen-containing bee bread. We quantified the transfer of PAs to nursing secretions produced by bees that had previously consumed bee bread supplemented with PAs. The PA concentration in these secretions was reduced by three orders of magnitude as compared to the PA content in the nurse diet and was well below the toxicity threshold for larvae. Our results suggest that larval nursing protects honeybee larvae from the toxic effect of secondary metabolites of pollen. PMID:29563265

Nursing protects honeybee larvae from secondary metabolites of pollen.

PubMed

Lucchetti, Matteo A; Kilchenmann, Verena; Glauser, Gaetan; Praz, Christophe; Kast, Christina

2018-03-28

The pollen of many plants contains toxic secondary compounds, sometimes in concentrations higher than those found in the flowers or leaves. The ecological significance of these compounds remains unclear, and their impact on bees is largely unexplored. Here, we studied the impact of pyrrolizidine alkaloids (PAs) found in the pollen of Echium vulgare on honeybee adults and larvae. Echimidine, a PA present in E. vulgare pollen, was isolated and added to the honeybee diets in order to perform toxicity bioassays. While adult bees showed relatively high tolerance to PAs, larvae were much more sensitive. In contrast to other bees, the honeybee larval diet typically contains only traces of pollen and consists predominantly of hypopharyngeal and mandibular secretions produced by nurse bees, which feed on large quantities of pollen-containing bee bread. We quantified the transfer of PAs to nursing secretions produced by bees that had previously consumed bee bread supplemented with PAs. The PA concentration in these secretions was reduced by three orders of magnitude as compared to the PA content in the nurse diet and was well below the toxicity threshold for larvae. Our results suggest that larval nursing protects honeybee larvae from the toxic effect of secondary metabolites of pollen. © 2018 The Authors.

Risks of neonicotinoid insecticides to honeybees

PubMed Central

Fairbrother, Anne; Purdy, John; Anderson, Troy; Fell, Richard

2014-01-01

The European honeybee, Apis mellifera, is an important pollinator of agricultural crops. Since 2006, when unexpectedly high colony losses were first reported, articles have proliferated in the popular press suggesting a range of possible causes and raising alarm over the general decline of bees. Suggested causes include pesticides, genetically modified crops, habitat fragmentation, and introduced diseases and parasites. Scientists have concluded that multiple factors in various combinations—including mites, fungi, viruses, and pesticides, as well as other factors such as reduction in forage, poor nutrition, and queen failure—are the most probable cause of elevated colony loss rates. Investigators and regulators continue to focus on the possible role that insecticides, particularly the neonicotinoids, may play in honeybee health. Neonicotinoid insecticides are insect neurotoxicants with desirable features such as broad-spectrum activity, low application rates, low mammalian toxicity, upward systemic movement in plants, and versatile application methods. Their distribution throughout the plant, including pollen, nectar, and guttation fluids, poses particular concern for exposure to pollinators. The authors describe how neonicotinoids interact with the nervous system of honeybees and affect individual honeybees in laboratory situations. Because honeybees are social insects, colony effects in semifield and field studies are discussed. The authors conclude with a review of current and proposed guidance in the United States and Europe for assessing the risks of pesticides to honeybees. PMID:24692231

Pesticide residues in honeybees, honey and bee pollen by LC-MS/MS screening: reported death incidents in honeybees.

PubMed

Kasiotis, Konstantinos M; Anagnostopoulos, Chris; Anastasiadou, Pelagia; Machera, Kyriaki

2014-07-01

The aim of this study was to investigate reported cases of honeybee death incidents with regard to the potential interrelation to the exposure to pesticides. Thus honeybee, bee pollen and honey samples from different areas of Greece were analyzed for the presence of pesticide residues. In this context an LC-ESI-MS/MS multiresidue method of total 115 analytes of different chemical classes such as neonicotinoids, organophosphates, triazoles, carbamates, dicarboximides and dinitroanilines in honeybee bodies, honey and bee pollen was developed and validated. The method presents good linearity over the ranges assayed with correlation coefficient values r(2)≥0.99, recoveries ranging for all matrices from 59 to 117% and precision (RSD%) values ranging from 4 to 27%. LOD and LOQ values ranged - for honeybees, honey and bee pollen - from 0.03 to 23.3 ng/g matrix weight and 0.1 up to 78 ng/g matrix weight, respectively. Therefore this method is sufficient to act as a monitoring tool for the determination of pesticide residues in cases of suspected honeybee poisoning incidents. From the analysis of the samples the presence of 14 active substances was observed in all matrices with concentrations ranging for honeybees from 0.3 to 81.5 ng/g, for bee pollen from 6.1 to 1273 ng/g and for honey one sample was positive to carbendazim at 1.6 ng/g. The latter confirmed the presence of such type of compounds in honeybee body and apicultural products. Copyright © 2014 Elsevier B.V. All rights reserved.

Method and device for identifying different species of honeybees

DOEpatents

Kerr, Howard T.; Buchanan, Michael E.; Valentine, Kenneth H.

1989-01-01

A method and device have been provided for distinguishing Africanized honeybees from European honeybees. The method is based on the discovery of a distinct difference in the acoustical signatures of these two species of honeybees in flight. The European honeybee signature has a fundamental power peak in the 210 to 240 Hz range while the Africanized honeybee signature has a fundamental power peak in the 260 to 290 Hz range. The acoustic signal produced by honeybees is analyzed by means of a detecting device to quickly determine the honeybee species through the detection of the presence of frequencies in one of these distinct ranges. The device includes a microphone for acoustical signal detection which feeds the detected signal into a frequency analyzer which is designed to detect the presence of either of the known fundamental wingbeat frequencies unique to the acoustical signatures of these species as an indication of the identity of the species and indicate the species identity on a readout device.

Infections of Nosema ceranae in four different honeybee species.

PubMed

Chaimanee, Veeranan; Warrit, Natapot; Chantawannakul, Panuwan

2010-10-01

The microsporidium Nosema ceranae is detected in honeybees in Thailand for the first time. This endoparasite has recently been reported to infect most Apis mellifera honeybee colonies in Europe, the US, and parts of Asia, and is suspected to have displaced the endemic endoparasite species, Nosema apis, from the western A. mellifera. We collected and identified species of microsporidia from the European honeybee (A. mellifera), the cavity nesting Asian honeybee (Apis cerana), the dwarf Asian honeybee (Apis florea) and the giant Asian honeybee (Apis dorsata) from colonies in Northern Thailand. We used multiplex PCR technique with two pairs of primers to differentiate N. ceranae from N. apis. From 80 A. mellifera samples, 62 (77.5%) were positively identified for the presence of the N. ceranae. Amongst 46 feral colonies of Asian honeybees (A. cerana, A. florea and A. dorsata) examined for Nosema infections, only N. ceranae could be detected. No N. apis was found in our samples. N. ceranae is found to be the only microsporidium infesting honeybees in Thailand. Moreover, we found the frequencies of N. ceranae infection in native bees to be less than that of A. mellifera. Copyright 2010 Elsevier Inc. All rights reserved.

Abscisic acid enhances cold tolerance in honeybee larvae

PubMed Central

Sturla, Laura; Guida, Lucrezia; Vigliarolo, Tiziana; Maggi, Matías; Eguaras, Martín; Zocchi, Elena; Lamattina, Lorenzo

2017-01-01

The natural composition of nutrients present in food is a key factor determining the immune function and stress responses in the honeybee (Apis mellifera). We previously demonstrated that a supplement of abscisic acid (ABA), a natural component of nectar, pollen, and honey, increases honeybee colony survival overwinter. Here we further explored the role of ABA in in vitro-reared larvae exposed to low temperatures. Four-day-old larvae (L4) exposed to 25°C for 3 days showed lower survival rates and delayed development compared to individuals growing at a standard temperature (34°C). Cold-stressed larvae maintained higher levels of ABA for longer than do larvae reared at 34°C, suggesting a biological significance for ABA. Larvae fed with an ABA-supplemented diet completely prevent the low survival rate due to cold stress and accelerate adult emergence. ABA modulates the expression of genes involved in metabolic adjustments and stress responses: Hexamerin 70b, Insulin Receptor Substrate, Vitellogenin, and Heat Shock Proteins 70. AmLANCL2, the honeybee ABA receptor, is also regulated by cold stress and ABA. These results support a role for ABA increasing the tolerance of honeybee larvae to low temperatures through priming effects. PMID:28381619

Abscisic acid enhances cold tolerance in honeybee larvae.

PubMed

Ramirez, Leonor; Negri, Pedro; Sturla, Laura; Guida, Lucrezia; Vigliarolo, Tiziana; Maggi, Matías; Eguaras, Martín; Zocchi, Elena; Lamattina, Lorenzo

2017-04-12

The natural composition of nutrients present in food is a key factor determining the immune function and stress responses in the honeybee ( Apis mellifera ). We previously demonstrated that a supplement of abscisic acid (ABA), a natural component of nectar, pollen, and honey, increases honeybee colony survival overwinter. Here we further explored the role of ABA in in vitro -reared larvae exposed to low temperatures. Four-day-old larvae (L4) exposed to 25°C for 3 days showed lower survival rates and delayed development compared to individuals growing at a standard temperature (34°C). Cold-stressed larvae maintained higher levels of ABA for longer than do larvae reared at 34°C, suggesting a biological significance for ABA. Larvae fed with an ABA-supplemented diet completely prevent the low survival rate due to cold stress and accelerate adult emergence. ABA modulates the expression of genes involved in metabolic adjustments and stress responses: Hexamerin 70b, Insulin Receptor Substrate, Vitellogenin , and Heat Shock Proteins 70. AmLANCL2, the honeybee ABA receptor, is also regulated by cold stress and ABA. These results support a role for ABA increasing the tolerance of honeybee larvae to low temperatures through priming effects. © 2017 The Author(s).

Ecological and evolutionary approaches to managing honeybee disease.

PubMed

Brosi, Berry J; Delaplane, Keith S; Boots, Michael; de Roode, Jacobus C

2017-09-01

Honeybee declines are a serious threat to global agricultural security and productivity. Although multiple factors contribute to these declines, parasites are a key driver. Disease problems in honeybees have intensified in recent years, despite increasing attention to addressing them. Here we argue that we must focus on the principles of disease ecology and evolution to understand disease dynamics, assess the severity of disease threats, and control these threats via honeybee management. We cover the ecological context of honeybee disease, including both host and parasite factors driving current transmission dynamics, and then discuss evolutionary dynamics including how beekeeping management practices may drive selection for more virulent parasites. We then outline how ecological and evolutionary principles can guide disease mitigation in honeybees, including several practical management suggestions for addressing short- and long-term disease dynamics and consequences.

Endangered Honeybee

ERIC Educational Resources Information Center

Bourne, Russell

1975-01-01

Because of pesticides, the disappearance of open farmland, chemical fertilizers, and our own indifference and ignorance, the number of United States honeybee colonies has been reduced an average of 2 percent per year. (BT)

The Magnetic Attraction of Honeybee Navigation.

ERIC Educational Resources Information Center

Ayres, David

1991-01-01

Discussed are the division of labor, defenses, genetics and evolution, communication, and navigation power of honeybees. The scientific and cross-curricular themes that can be offered using the economically important honeybee are described. Research that suggests that bees may be flying magnets is also discussed. (KR)

Honeybees show adaptive reactions to ethanol exposure.

PubMed

Miler, Krzysztof; Kuszewska, Karolina; Privalova, Valeriya; Woyciechowski, Michal

2018-06-07

The honeybee is being developed as a simple invertebrate model for alcohol-related studies. To date, several effects of ethanol consumption have been demonstrated in honeybees, but the tolerance effect, one of the hallmarks of alcohol overuse, has never been shown. Here, we confirm our hypothesis that the response to ethanol (in terms of motor impairment) is lower in bees that have previously experienced intoxication than in bees encountering ethanol for the first time, indicating that the chronic tolerance effect occurs in honeybees. Furthermore, we investigated the basis of this effect and found that it likely results from conditioned compensatory responses to cues associated with ethanol delivery. Our findings significantly improve our understanding of the suitability of honeybees as models for alcoholism-related research and underline the first and foremost function of all conditioned reactions - their adaptive value.

Multiple pesticide residues in live and poisoned honeybees - Preliminary exposure assessment.

PubMed

Kiljanek, Tomasz; Niewiadowska, Alicja; Gaweł, Marta; Semeniuk, Stanisław; Borzęcka, Milena; Posyniak, Andrzej; Pohorecka, Krystyna

2017-05-01

Study combines data about the exposure of honeybees to pesticides from plant protection products and veterinary medicinal products. Residues of 200 pesticide and pesticide metabolites in 343 live and 74 poisoned honeybee samples, obtained during the years of 2014-2015, were determined by LC-MS/MS and GC-MS/MS. In 44% of live honeybee 48 different pesticide residues were found, mainly amitraz metabolites (DMF, DMPF) and chlorpyrifos. In 98% of poisoned honeybee 57 pesticides and metabolites were detected, mainly chlorpyrifos, dimethoate and clothianidin. In total 84 different pesticides were detected both in live and poisoned honeybees, they indicate 30 various modes of action. Differences between mean number of pesticide residues detected in live and poisoned honeybees clearly indicate the impact of multiple pesticides on honeybee health. Possible impact of systemic fungicides on the health of honeybees was studied. Applicability of hazard quotient counted as ratio between concentration of pesticides in honeybees and lethal dose in the interpretation whether detected concentration indicates acute toxic effects was shown. Copyright © 2017 Elsevier Ltd. All rights reserved.

Odor Experiences during Preimaginal Stages Cause Behavioral and Neural Plasticity in Adult Honeybees.

PubMed

Ramírez, Gabriela; Fagundez, Carol; Grosso, Juan P; Argibay, Pablo; Arenas, Andrés; Farina, Walter M

2016-01-01

In eusocial insects, experiences acquired during the development have long-term consequences on mature behavior. In the honeybee that suffers profound changes associated with metamorphosis, the effect of odor experiences at larval instars on the subsequent physiological and behavioral response is still unclear. To address the impact of preimaginal experiences on the adult honeybee, colonies containing larvae were fed scented food. The effect of the preimaginal experiences with the food odor was assessed in learning performance, memory retention and generalization in 3-5- and 17-19 day-old bees, in the regulation of their expression of synaptic-related genes and in the perception and morphology of their antennae. Three-five day old bees that experienced 1-hexanol (1-HEX) as food scent responded more to the presentation of the odor during the 1-HEX conditioning than control bees (i.e., bees reared in colonies fed unscented food). Higher levels of proboscis extension response (PER) to 1-HEX in this group also extended to HEXA, the most perceptually similar odor to the experienced one that we tested. These results were not observed for the group tested at older ages. In the brain of young adults, larval experiences triggered similar levels of neurexins (NRXs) and neuroligins (Nlgs) expression, two proteins that have been involved in synaptic formation after associative learning. At the sensory periphery, the experience did not alter the number of the olfactory sensilla placoidea, but did reduce the electrical response of the antennae to the experienced and novel odor. Our study provides a new insight into the effects of preimaginal experiences in the honeybee and the mechanisms underlying olfactory plasticity at larval stage of holometabolous insects.

Enhancement of chronic bee paralysis virus levels in honeybees acute exposed to imidacloprid: A Chinese case study.

PubMed

Diao, Qingyun; Li, Beibei; Zhao, Hongxia; Wu, Yanyan; Guo, Rui; Dai, Pingli; Chen, Dafu; Wang, Qiang; Hou, Chunsheng

2018-07-15

Though honeybee populations have not yet been reported to be largely lost in China, many stressors that affect the health of honeybees have been confirmed. Honeybees inevitably come into contact with environmental stressors that are not intended to target honeybees, such as pesticides. Although large-scale losses of honeybee colonies are thought to be associated with viruses, these viruses usually lead to covert infections and to not cause acute damage if the bees do not encounter outside stressors. To reveal the potential relationship between acute pesticides and viruses, we applied different doses of imidacloprid to adult bees that were primarily infected with low levels (4.3×10 5 genome copies) of chronic bee paralysis virus (CBPV) to observe whether the acute oral toxicity of imidacloprid was able to elevate the level of CBPV. Here, we found that the titer of CBPV was significantly elevated in adult bees after 96h of acute treatment with imidacloprid at the highest dose 66.9ng/bee compared with other treatments and controls. Our study provides clear evidence that exposure to acute high doses of imidacloprid in honeybees persistently infected by CBPV can exert a remarkably negative effect on honeybee survival. These results imply that acute environmental stressors might be one of the major accelerators causing rapid viral replication, which may progress to cause mass proliferation and dissemination and lead to colony decline. The present study will be useful for better understanding the harm caused by this pesticide, especially regarding how honeybee tolerance to the viral infection might be altered by acute pesticide exposure. Copyright © 2018 Elsevier B.V. All rights reserved.

The Brazilian Honeybee

ERIC Educational Resources Information Center

Michener, Charles D.

1973-01-01

Discusses the unusually aggressive Brazilian honeybee, which exhibits many of the attributes of its African antecedants. Describes its abundance and distribution, behaviorial characteristics, future spread, and the potential impact of the Brazilian bee in North America. (JR)

Visual discrimination transfer and modulation by biogenic amines in honeybees.

PubMed

Vieira, Amanda Rodrigues; Salles, Nayara; Borges, Marco; Mota, Theo

2018-05-10

For more than a century, visual learning and memory have been studied in the honeybee Apis mellifera using operant appetitive conditioning. Although honeybees show impressive visual learning capacities in this well-established protocol, operant training of free-flying animals cannot be combined with invasive protocols for studying the neurobiological basis of visual learning. In view of this, different attempts have been made to develop new classical conditioning protocols for studying visual learning in harnessed honeybees, though learning performance remains considerably poorer than that for free-flying animals. Here, we investigated the ability of honeybees to use visual information acquired during classical conditioning in a new operant context. We performed differential visual conditioning of the proboscis extension reflex (PER) followed by visual orientation tests in a Y-maze. Classical conditioning and Y-maze retention tests were performed using the same pair of perceptually isoluminant chromatic stimuli, to avoid the influence of phototaxis during free-flying orientation. Visual discrimination transfer was clearly observed, with pre-trained honeybees significantly orienting their flights towards the former positive conditioned stimulus (CS+), thus showing that visual memories acquired by honeybees are resistant to context changes between conditioning and the retention test. We combined this visual discrimination approach with selective pharmacological injections to evaluate the effect of dopamine and octopamine in appetitive visual learning. Both octopaminergic and dopaminergic antagonists impaired visual discrimination performance, suggesting that both these biogenic amines modulate appetitive visual learning in honeybees. Our study brings new insight into cognitive and neurobiological mechanisms underlying visual learning in honeybees. © 2018. Published by The Company of Biologists Ltd.

Odor Experiences during Preimaginal Stages Cause Behavioral and Neural Plasticity in Adult Honeybees

PubMed Central

Ramírez, Gabriela; Fagundez, Carol; Grosso, Juan P.; Argibay, Pablo; Arenas, Andrés; Farina, Walter M.

2016-01-01

In eusocial insects, experiences acquired during the development have long-term consequences on mature behavior. In the honeybee that suffers profound changes associated with metamorphosis, the effect of odor experiences at larval instars on the subsequent physiological and behavioral response is still unclear. To address the impact of preimaginal experiences on the adult honeybee, colonies containing larvae were fed scented food. The effect of the preimaginal experiences with the food odor was assessed in learning performance, memory retention and generalization in 3–5- and 17–19 day-old bees, in the regulation of their expression of synaptic-related genes and in the perception and morphology of their antennae. Three-five day old bees that experienced 1-hexanol (1-HEX) as food scent responded more to the presentation of the odor during the 1-HEX conditioning than control bees (i.e., bees reared in colonies fed unscented food). Higher levels of proboscis extension response (PER) to 1-HEX in this group also extended to HEXA, the most perceptually similar odor to the experienced one that we tested. These results were not observed for the group tested at older ages. In the brain of young adults, larval experiences triggered similar levels of neurexins (NRXs) and neuroligins (Nlgs) expression, two proteins that have been involved in synaptic formation after associative learning. At the sensory periphery, the experience did not alter the number of the olfactory sensilla placoidea, but did reduce the electrical response of the antennae to the experienced and novel odor. Our study provides a new insight into the effects of preimaginal experiences in the honeybee and the mechanisms underlying olfactory plasticity at larval stage of holometabolous insects. PMID:27375445

Do honeybees shape the bacterial community composition in floral nectar?

PubMed

Aizenberg-Gershtein, Yana; Izhaki, Ido; Halpern, Malka

2013-01-01

Floral nectar is considered the most important reward animal-pollinated plants offer to attract pollinators. Here we explore whether honeybees, which act as pollinators, affect the composition of bacterial communities in the nectar. Nectar and honeybees were sampled from two plant species: Amygdalus communis and Citrus paradisi. To prevent the contact of nectar with pollinators, C. paradisi flowers were covered with net bags before blooming (covered flowers). Comparative analysis of bacterial communities in the nectar and on the honeybees was performed by the 454-pyrosequencing technique. No significant differences were found among bacterial communities in honeybees captured on the two different plant species. This resemblance may be due to the presence of dominant bacterial OTUs, closely related to the Arsenophonus genus. The bacterial communities of the nectar from the covered and uncovered C. paradisi flowers differed significantly; the bacterial communities on the honeybees differed significantly from those in the covered flowers' nectar, but not from those in the uncovered flowers' nectar. We conclude that the honeybees may introduce bacteria into the nectar and/or may be contaminated by bacteria introduced into the nectar by other sources such as other pollinators and nectar thieves.

Do Honeybees Shape the Bacterial Community Composition in Floral Nectar?

PubMed Central

Aizenberg-Gershtein, Yana; Izhaki, Ido; Halpern, Malka

2013-01-01

Floral nectar is considered the most important reward animal-pollinated plants offer to attract pollinators. Here we explore whether honeybees, which act as pollinators, affect the composition of bacterial communities in the nectar. Nectar and honeybees were sampled from two plant species: Amygdalus communis and Citrus paradisi. To prevent the contact of nectar with pollinators, C. paradisi flowers were covered with net bags before blooming (covered flowers). Comparative analysis of bacterial communities in the nectar and on the honeybees was performed by the 454-pyrosequencing technique. No significant differences were found among bacterial communities in honeybees captured on the two different plant species. This resemblance may be due to the presence of dominant bacterial OTUs, closely related to the Arsenophonus genus. The bacterial communities of the nectar from the covered and uncovered C. paradisi flowers differed significantly; the bacterial communities on the honeybees differed significantly from those in the covered flowers’ nectar, but not from those in the uncovered flowers’ nectar. We conclude that the honeybees may introduce bacteria into the nectar and/or may be contaminated by bacteria introduced into the nectar by other sources such as other pollinators and nectar thieves. PMID:23844027

The dynamic association between ovariole loss and sterility in adult honeybee workers

PubMed Central

Allsopp, Michael H.; Tan, Ken; Dong, Shihao; Liu, Xiwen; Vergoz, Vanina

2017-01-01

In the social insects, ovary state (the presence or absence of mature oocytes) and ovary size (the number of ovarioles) are often used as proxies for the reproductive capacity of an individual worker. Ovary size is assumed to be fixed post-eclosion whereas ovary state is demonstrably plastic post-eclosion. Here, we show that in fact ovary size declines as honeybee workers age. This finding is robust across two honeybee species: Apis mellifera and A. cerana. The ovariole loss is likely to be due to the regression of particular ovarioles via programmed cell death. We also provide further support for the observation that honeybee workers with activated ovaries (mature oocytes present) most commonly have five ovarioles rather than a greater or smaller number. This result suggests that workers with more than five ovarioles are unable to physiologically support more than five activated ovarioles and that workers with fewer than five ovarioles are below a threshold necessary for ovary activation. As a worker's ovariole number declines with age, studies on worker ovariole number need to take this plasticity into account. PMID:28356452

Altitude control in honeybees: joint vision-based learning and guidance.

PubMed

Portelli, Geoffrey; Serres, Julien R; Ruffier, Franck

2017-08-23

Studies on insects' visual guidance systems have shed little light on how learning contributes to insects' altitude control system. In this study, honeybees were trained to fly along a double-roofed tunnel after entering it near either the ceiling or the floor of the tunnel. The honeybees trained to hug the ceiling therefore encountered a sudden change in the tunnel configuration midways: i.e. a "dorsal ditch". Thus, the trained honeybees met a sudden increase in the distance to the ceiling, corresponding to a sudden strong change in the visual cues available in their dorsal field of view. Honeybees reacted by rising quickly and hugging the new, higher ceiling, keeping a similar forward speed, distance to the ceiling and dorsal optic flow to those observed during the training step; whereas bees trained to follow the floor kept on following the floor regardless of the change in the ceiling height. When trained honeybees entered the tunnel via the other entry (the lower or upper entry) to that used during the training step, they quickly changed their altitude and hugged the surface they had previously learned to follow. These findings clearly show that trained honeybees control their altitude based on visual cues memorized during training. The memorized visual cues generated by the surfaces followed form a complex optic flow pattern: trained honeybees may attempt to match the visual cues they perceive with this memorized optic flow pattern by controlling their altitude.

A SNP test to identify Africanized honeybees via proportion of 'African' ancestry.

PubMed

Chapman, Nadine C; Harpur, Brock A; Lim, Julianne; Rinderer, Thomas E; Allsopp, Michael H; Zayed, Amro; Oldroyd, Benjamin P

2015-11-01

The honeybee, Apis mellifera, is the world's most important pollinator and is ubiquitous in most agricultural ecosystems. Four major evolutionary lineages and at least 24 subspecies are recognized. Commercial populations are mainly derived from subspecies originating in Europe (75-95%). The Africanized honeybee is a New World hybrid of A. m. scutellata from Africa and European subspecies, with the African component making up 50-90% of the genome. Africanized honeybees are considered undesirable for bee-keeping in most countries, due to their extreme defensiveness and poor honey production. The international trade in honeybees is restricted, due in part to bans on the importation of queens (and semen) from countries where Africanized honeybees are extant. Some desirable strains from the United States of America that have been bred for traits such as resistance to the mite Varroa destructor are unfortunately excluded from export to countries such as Australia due to the presence of Africanized honeybees in the USA. This study shows that a panel of 95 single nucleotide polymorphisms, chosen to differentiate between the African, Eastern European and Western European lineages, can detect Africanized honeybees with a high degree of confidence via ancestry assignment. Our panel therefore offers a valuable tool to mitigate the risks of spreading Africanized honeybees across the globe and may enable the resumption of queen and bee semen imports from the Americas. © 2015 John Wiley & Sons Ltd.

Olfactory Blocking and Odorant Similarity in the Honeybee

ERIC Educational Resources Information Center

Gerber, Bertram; Giurfa, Martin; Guerrieri, Fernando; Lachnit, Harald

2005-01-01

Blocking occurs when previous training with a stimulus A reduces (blocks) subsequent learning about a stimulus B, when A and B are trained in compound. The question of whether blocking exists in olfactory conditioning of proboscis extension reflex (PER) in honeybees is under debate. The last published accounts on blocking in honeybees state that…

[Staphylococcus aureus infection in Apis mellifera L. (honeybees)].

PubMed

Keskin, N

1989-07-01

The causative agent of American foulbrood is Bacillus larvae, the causes of the European foulbrood diseases are Streptococcus pluton and Bacillus alvei and the causes of the septicemia are Pseudomonas apiseptica and Escherichia coli in honeybees (Apis mellifera). Apart from the above causative agents in this study, Staphylococcus aureus has been isolated and identified from honeybees (Apis mellifera).

Deformed wing virus implicated in overwintering honeybee colony losses.

PubMed

Highfield, Andrea C; El Nagar, Aliya; Mackinder, Luke C M; Noël, Laure M-L J; Hall, Matthew J; Martin, Stephen J; Schroeder, Declan C

2009-11-01

The worldwide decline in honeybee colonies during the past 50 years has often been linked to the spread of the parasitic mite Varroa destructor and its interaction with certain honeybee viruses. Recently in the United States, dramatic honeybee losses (colony collapse disorder) have been reported; however, there remains no clear explanation for these colony losses, with parasitic mites, viruses, bacteria, and fungal diseases all being proposed as possible candidates. Common characteristics that most failing colonies share is a lack of overt disease symptoms and the disappearance of workers from what appears to be normally functioning colonies. In this study, we used quantitative PCR to monitor the presence of three honeybee viruses, deformed wing virus (DWV), acute bee paralysis virus (ABPV), and black queen cell virus (BQCV), during a 1-year period in 15 asymptomatic, varroa mite-positive honeybee colonies in Southern England, and 3 asymptomatic colonies confirmed to be varroa mite free. All colonies with varroa mites underwent control treatments to ensure that mite populations remained low throughout the study. Despite this, multiple virus infections were detected, yet a significant correlation was observed only between DWV viral load and overwintering colony losses. The long-held view has been that DWV is relatively harmless to the overall health status of honeybee colonies unless it is in association with severe varroa mite infestations. Our findings suggest that DWV can potentially act independently of varroa mites to bring about colony losses. Therefore, DWV may be a major factor in overwintering colony losses.

Conservation of Bio synthetic pheromone pathways in honeybees Apis

NASA Astrophysics Data System (ADS)

Martin, Stephen J.; Jones, Graeme R.

Social insects use complex chemical communication systems to govern many aspects of their life. We studied chemical changes in Dufour's gland secretions associated with ovary development in several genotypes of honeybees. We found that C28-C38 esters were associated only with cavity nesting honeybee queens, while the alcohol eicosenol was associated only with their non-laying workers. In contrast, both egg-laying anarchistic workers and all parasitic Cape workers from queenright colonies showed the typical queen pattern (i.e. esters present and eicosenol absent), while egg-laying wild-type and anarchistic workers in queenless colonies showed an intermediate pattern, producing both esters and eicosenol but at intermediate levels. Furthermore, neither esters nor eicosenol were found in aerial nesting honeybee species. Both esters and eicosenol are biosynthetically similar compounds since both are recognizable products of fatty acid biosynthesis. Therefore, we propose that in honeybees the biosynthesis of esters and eicosenol in the Dufour's gland is caste-regulated and this pathway has been conserved over evolutionary time.

Impaired Olfactory Associative Behavior of Honeybee Workers Due to Contamination of Imidacloprid in the Larval Stage

PubMed Central

Yang, En-Cheng; Chang, Hui-Chun; Wu, Wen-Yen; Chen, Yu-Wen

2012-01-01

The residue of imidacloprid in the nectar and pollens of the plants is toxic not only to adult honeybees but also the larvae. Our understanding of the risk of imidacloprid to larvae of the honeybees is still in a very early stage. In this study, the capped-brood, pupation and eclosion rates of the honeybee larvae were recorded after treating them directly in the hive with different dosages of imidacloprid. The brood-capped rates of the larvae decreased significantly when the dosages increased from 24 to 8000 ng/larva. However, there were no significant effects of DMSO or 0.4 ng of imidacloprid per larva on the brood-capped, pupation and eclosion rates. Although the sublethal dosage of imidacloprid had no effect on the eclosion rate, we found that the olfactory associative behavior of the adult bees was impaired if they had been treated with 0.04 ng/larva imidacloprid in the larval stage. These results demonstrate that a sublethal dosage of imidacloprid given to the larvae affects the subsequent associative ability of the adult honeybee workers. Thus, a low dose of imidacloprid may affect the survival condition of the entire colony, even though the larvae survive to adulthood. PMID:23166680

Effects of sublethal doses of glyphosate on honeybee navigation.

PubMed

Balbuena, María Sol; Tison, Léa; Hahn, Marie-Luise; Greggers, Uwe; Menzel, Randolf; Farina, Walter M

2015-09-01

Glyphosate (GLY) is a herbicide that is widely used in agriculture for weed control. Although reports about the impact of GLY in snails, crustaceans and amphibians exist, few studies have investigated its sublethal effects in non-target organisms such as the honeybee Apis mellifera, the main pollen vector in commercial crops. Here, we tested whether exposure to three sublethal concentrations of GLY (2.5, 5 and 10 mg l(-1): corresponding to 0.125, 0.250 and 0.500 μg per animal) affects the homeward flight path of honeybees in an open field. We performed an experiment in which forager honeybees were trained to an artificial feeder, and then captured, fed with sugar solution containing traces of GLY and released from a novel site either once or twice. Their homeward trajectories were tracked using harmonic radar technology. We found that honeybees that had been fed with solution containing 10 mg l(-1) GLY spent more time performing homeward flights than control bees or bees treated with lower concentrations. They also performed more indirect homing flights. Moreover, the proportion of direct homeward flights performed after a second release from the same site increased in control bees but not in treated bees. These results suggest that, in honeybees, exposure to levels of GLY commonly found in agricultural settings impairs the cognitive capacities needed to retrieve and integrate spatial information for a successful return to the hive. Therefore, honeybee navigation is affected by ingesting traces of the most widely used herbicide worldwide, with potential long-term negative consequences for colony foraging success. © 2015. Published by The Company of Biologists Ltd.

Honeybee product therapeutic as stem cells homing for ovary failure.

PubMed

Safitri, Erma; Widiyatno, Thomas V; Prasetyo, R Heru

2016-11-01

Complexity of the method of isolation, cultivation in vitro and the expensive cost of transplantation process of stem cells, it would require an innovation to homing and differentiation of stem cells and increase folliculogenesis. The stem cells homing was achieved through the provision of food or beverages derived from natural materials like honeybee product. Through honeybee product, there will be homing of stem cells and accompany with the sources from the body itself will take place in regeneration of the ovary. Female rats model of degenerative ovary was obtained through food fasting but still have drinking water for 5 days. It caused malnutrition and damage of the ovarian tissue. The administration of 50% honeybee product (T1) was performed for 10 consecutive days, while the positive control group (T0+) was fasted and not given honeybee product and the negative control (T0-) not fasted and without honeybee product. Observations were taken for homing of stem cells, raised of folliculogenesis, differentiation of stem cells, and regeneration of the ovarian tissue using routine H&E staining. Homing of stem cells shown the vascular endothelial growth factor and granulocyte colony-stimulating factor expression; enhancement of folliculogenesis was indicated by an increase of follicle dee Graaf count; enhancement of differentiation of stem cells was indicated by growth differentiation factor-9 expression; and regeneration of ovarian tissue indicated by intact ovarian tissue with growing follicles. Honeybee product can be induced endogenous stem cells in regeneration of ovary failure due to malnutrition.

Comparison of Varroa destructor and Worker Honeybee Microbiota Within Hives Indicates Shared Bacteria.

PubMed

Hubert, Jan; Kamler, Martin; Nesvorna, Marta; Ledvinka, Ondrej; Kopecky, Jan; Erban, Tomas

2016-08-01

The ectoparasitic mite Varroa destructor is a major pest of the honeybee Apis mellifera. In a previous study, bacteria were found in the guts of mites collected from winter beehive debris and were identified using Sanger sequencing of their 16S rRNA genes. In this study, community comparison and diversity analyses were performed to examine the microbiota of honeybees and mites at the population level. The microbiota of the mites and honeybees in 26 colonies in seven apiaries in Czechia was studied. Between 10 and 50 Varroa females were collected from the bottom board, and 10 worker bees were removed from the peripheral comb of the same beehive. Both bees and mites were surface sterilized. Analysis of the 16S rRNA gene libraries revealed significant differences in the Varroa and honeybee microbiota. The Varroa microbiota was less diverse than was the honeybee microbiota, and the relative abundances of bacterial taxa in the mite and bee microbiota differed. The Varroa mites, but not the honeybees, were found to be inhabited by Diplorickettsia. The relative abundance of Arsenophonus, Morganella, Spiroplasma, Enterococcus, and Pseudomonas was higher in Varroa than in honeybees, and the Diplorickettsia symbiont detected in this study is specific to Varroa mites. The results demonstrated that there are shared bacteria between Varroa and honeybee populations but that these bacteria occur in different relative proportions in the honeybee and mite bacteriomes. These results support the suggestion of bacterial transfer via mites, although only some of the transferred bacteria may be harmful.

How Do Honeybees Attract Nestmates Using Waggle Dances in Dark and Noisy Hives?

PubMed Central

Hasegawa, Yuji; Ikeno, Hidetoshi

2011-01-01

It is well known that honeybees share information related to food sources with nestmates using a dance language that is representative of symbolic communication among non-primates. Some honeybee species engage in visually apparent behavior, walking in a figure-eight pattern inside their dark hives. It has been suggested that sounds play an important role in this dance language, even though a variety of wing vibration sounds are produced by honeybee behaviors in hives. It has been shown that dances emit sounds primarily at about 250–300 Hz, which is in the same frequency range as honeybees' flight sounds. Thus the exact mechanism whereby honeybees attract nestmates using waggle dances in such a dark and noisy hive is as yet unclear. In this study, we used a flight simulator in which honeybees were attached to a torque meter in order to analyze the component of bees' orienting response caused only by sounds, and not by odor or by vibrations sensed by their legs. We showed using single sound localization that honeybees preferred sounds around 265 Hz. Furthermore, according to sound discrimination tests using sounds of the same frequency, honeybees preferred rhythmic sounds. Our results demonstrate that frequency and rhythmic components play a complementary role in localizing dance sounds. Dance sounds were presumably developed to share information in a dark and noisy environment. PMID:21603608

A robotic system for researching social integration in honeybees.

PubMed

Griparić, Karlo; Haus, Tomislav; Miklić, Damjan; Polić, Marsela; Bogdan, Stjepan

2017-01-01

In this paper, we present a novel robotic system developed for researching collective social mechanisms in a biohybrid society of robots and honeybees. The potential for distributed coordination, as observed in nature in many different animal species, has caused an increased interest in collective behaviour research in recent years because of its applicability to a broad spectrum of technical systems requiring robust multi-agent control. One of the main problems is understanding the mechanisms driving the emergence of collective behaviour of social animals. With the aim of deepening the knowledge in this field, we have designed a multi-robot system capable of interacting with honeybees within an experimental arena. The final product, stationary autonomous robot units, designed by specificaly considering the physical, sensorimotor and behavioral characteristics of the honeybees (lat. Apis mallifera), are equipped with sensing, actuating, computation, and communication capabilities that enable the measurement of relevant environmental states, such as honeybee presence, and adequate response to the measurements by generating heat, vibration and airflow. The coordination among robots in the developed system is established using distributed controllers. The cooperation between the two different types of collective systems is realized by means of a consensus algorithm, enabling the honeybees and the robots to achieve a common objective. Presented results, obtained within ASSISIbf project, show successful cooperation indicating its potential for future applications.

Migration effects on population dynamics of the honeybee-mite interactions

USDA-ARS?s Scientific Manuscript database

Honeybees are amazing and highly beneficial insect species that play important roles in undisturbed and agricultural ecosystems. Unfortunately, honeybees are increasingly threatened by numerous factors, most notably the parasitic Varroa mite (Varroa destructor Anderson and Trueman). A recent field s...

Stable gastric pentadecapeptide BPC 157 in honeybee (Apis mellifera) therapy, to control Nosema ceranae invasions in apiary conditions.

PubMed

Tlak Gajger, I; Ribarić, J; Smodiš Škerl, M; Vlainić, J; Sikirić, P

2018-04-23

Nosema ceranae can cause major problems, such as immune suppression, gut epithelial cell degeneration, reduced honeybee lifespan, or suddenly colony collapse. As a novel approach in therapy, we hypothesize the stable gastric pentadecapeptide BPC 157 in honeybee therapy, to control N. ceranae invasions in apiary conditions: BPC 157 treated sugar syrup (0.25 L sugar syrup supplemented with 0.1 μg/ml BPC 157), as well as the pure sugar syrup (0.25 L sugar syrup; control), was administered to honeybee colonies in feeders situated under the roof of the hives, during 21 consecutive days, at the end of beekeeping season. The strength of honeybee colonies was increased 20 and 30 days after initial feeding with BPC 157 supplement (Day 1, 36.100 ± 698; Day 20, 64.860 ± 468; Day 30, 53.214 ± 312 estimated number of honeybees), in field conditions. The similar successful outcome occurs with the N. ceranae spore loads counted in the homogenates of sampled adult honeybees (Day 1, 6.286 ± 2.336; Day 20, 3.753 ± 1.835; Day 30, 2.005 ± 1.534 million spores/bee). Accordingly, with the noted increased strength of the colonies fed with sugar syrup supplemented with BPC 157, the number of N. ceranae spores per honeybee gradually decreased as well. Besides, honeybees infected with N. ceranae fed with sugar syrup exhibited severe damage of midgut wall layers and epithelial cells. By contrast, in honeybees infected with N. ceranae fed with sugar syrup supplemented with BPC 157, all damages were markedly attenuated, damages of the outer muscular coat, in particular. In conclusion, the results of the first field trial on diseased honeybee colonies with BPC 157 indicate significant therapeutic effects with the used oral therapy with BPC 157 supplementation. © 2018 John Wiley & Sons Ltd.

Genetic variation in natural honeybee populations, Apis mellifera capensis

NASA Astrophysics Data System (ADS)

Hepburn, Randall; Neumann, Peter; Radloff, Sarah E.

2004-09-01

Genetic variation in honeybee, Apis mellifera, populations can be considerably influenced by breeding and commercial introductions, especially in areas with abundant beekeeping. However, in southern Africa apiculture is based on the capture of wild swarms, and queen rearing is virtually absent. Moreover, the introduction of European subspecies constantly failed in the Cape region. We therefore hypothesize a low human impact on genetic variation in populations of Cape honeybees, Apis mellifera capensis. A novel solution to studying genetic variation in honeybee populations based on thelytokous worker reproduction is applied to test this hypothesis. Environmental effects on metrical morphological characters of the phenotype are separated to obtain a genetic residual component. The genetic residuals are then re-calculated as coefficients of genetic variation. Characters measured included hair length on the abdomen, width and length of wax plate, and three wing angles. The data show for the first time that genetic variation in Cape honeybee populations is independent of beekeeping density and probably reflects naturally occurring processes such as gene flow due to topographic and climatic variation on a microscale.

Conserving genetic diversity in the honeybee: comments on Harpur et al. (2012).

PubMed

De la Rúa, Pilar; Jaffé, Rodolfo; Muñoz, Irene; Serrano, José; Moritz, Robin F A; Kraus, F Bernhard

2013-06-01

The article by Harpur et al. (2012) 'Management increases genetic diversity of honey bees via admixture' concludes that '…honey bees do not suffer from reduced genetic diversity caused by management and, consequently, that reduced genetic diversity is probably not contributing to declines of managed Apis mellifera populations'. In the light of current honeybee and beekeeping declines and their consequences for honeybee conservation and the pollination services they provide, we would like to express our concern about the conclusions drawn from the results of Harpur et al. (2012). While many honeybee management practices do not imply admixture, we are convinced that the large-scale genetic homogenization of admixed populations could drive the loss of valuable local adaptations. We also point out that the authors did not account for the extensive gene flow that occurs between managed and wild/feral honeybee populations and raise concerns about the data set used. Finally, we caution against underestimating the importance of genetic diversity for honeybee colonies and highlight the importance of promoting the use of endemic honeybee subspecies in apiculture. © 2013 John Wiley & Sons Ltd.

Lateralization of visual learning in the honeybee.

PubMed

Letzkus, Pinar; Boeddeker, Norbert; Wood, Jeff T; Zhang, Shao-Wu; Srinivasan, Mandyam V

2008-02-23

Lateralization is a well-described phenomenon in humans and other vertebrates and there are interesting parallels across a variety of different vertebrate species. However, there are only a few studies of lateralization in invertebrates. In a recent report, we showed lateralization of olfactory learning in the honeybee (Apis mellifera). Here, we investigate lateralization of another sensory modality, vision. By training honeybees on a modified version of a visual proboscis extension reflex task, we find that bees learn a colour stimulus better with their right eye.

Heat-balling wasps by honeybees

NASA Astrophysics Data System (ADS)

Ken, Tan; Hepburn, H. R.; Radloff, S. E.; Yusheng, Yu; Yiqiu, Liu; Danyin, Zhou; Neumann, P.

2005-10-01

Defensiveness of honeybee colonies of Apis cerana and Apis mellifera (actively balling the wasps but reduction of foraging) against predatory wasps, Vespa velutina, and false wasps was assessed. There were significantly more worker bees in balls of the former than latter. Core temperatures in a ball around a live wasp of A. cerana were significantly higher than those of A. mellifera, and also significantly more when exposed to false wasps. Core temperatures of bee balls exposed to false wasps were significantly lower than those exposed to V. velutina for both A. cerana and for A. mellifera. The lethal thermal limits for V. velutina, A. cerana and A. mellifera were significantly different, so that both species of honeybees have a thermal safety factor in heat-killing such wasp predators. During wasps attacks at the hives measured at 3, 6 and 12 min, the numbers of Apis cerana cerana and Apis cerana indica bees continuing to forage were significantly reduced with increased wasp attack time. Tropical lowland A. c. indica reduced foraging rates significantly more than the highland A. c. cerana bees; but, there was no significant effect on foraging by A. mellifera. The latency to recovery of honeybee foraging was significantly greater the longer the duration of wasp attacks. The results show remarkable thermal fine-tuning in a co-evolving predator prey relationship.

Honeybees can discriminate between Monet and Picasso paintings.

PubMed

Wu, Wen; Moreno, Antonio M; Tangen, Jason M; Reinhard, Judith

2013-01-01

Honeybees (Apis mellifera) have remarkable visual learning and discrimination abilities that extend beyond learning simple colours, shapes or patterns. They can discriminate landscape scenes, types of flowers, and even human faces. This suggests that in spite of their small brain, honeybees have a highly developed capacity for processing complex visual information, comparable in many respects to vertebrates. Here, we investigated whether this capacity extends to complex images that humans distinguish on the basis of artistic style: Impressionist paintings by Monet and Cubist paintings by Picasso. We show that honeybees learned to simultaneously discriminate between five different Monet and Picasso paintings, and that they do not rely on luminance, colour, or spatial frequency information for discrimination. When presented with novel paintings of the same style, the bees even demonstrated some ability to generalize. This suggests that honeybees are able to discriminate Monet paintings from Picasso ones by extracting and learning the characteristic visual information inherent in each painting style. Our study further suggests that discrimination of artistic styles is not a higher cognitive function that is unique to humans, but simply due to the capacity of animals-from insects to humans-to extract and categorize the visual characteristics of complex images.

Reconciling laboratory and field assessments of neonicotinoid toxicity to honeybees

PubMed Central

Henry, Mickaël; Cerrutti, Nicolas; Aupinel, Pierrick; Decourtye, Axel; Gayrard, Mélanie; Odoux, Jean-François; Pissard, Aurélien; Rüger, Charlotte; Bretagnolle, Vincent

2015-01-01

European governments have banned the use of three common neonicotinoid pesticides due to insufficiently identified risks to bees. This policy decision is controversial given the absence of clear consistency between toxicity assessments of those substances in the laboratory and in the field. Although laboratory trials report deleterious effects in honeybees at trace levels, field surveys reveal no decrease in the performance of honeybee colonies in the vicinity of treated fields. Here we provide the missing link, showing that individual honeybees near thiamethoxam-treated fields do indeed disappear at a faster rate, but the impact of this is buffered by the colonies' demographic regulation response. Although we could ascertain the exposure pathway of thiamethoxam residues from treated flowers to honeybee dietary nectar, we uncovered an unexpected pervasive co-occurrence of similar concentrations of imidacloprid, another neonicotinoid normally restricted to non-entomophilous crops in the study country. Thus, its origin and transfer pathways through the succession of annual crops need be elucidated to conveniently appraise the risks of combined neonicotinoid exposures. This study reconciles the conflicting laboratory and field toxicity assessments of neonicotinoids on honeybees and further highlights the difficulty in actually detecting non-intentional effects on the field through conventional risk assessment methods. PMID:26582026

Reconciling laboratory and field assessments of neonicotinoid toxicity to honeybees.

PubMed

Henry, Mickaël; Cerrutti, Nicolas; Aupinel, Pierrick; Decourtye, Axel; Gayrard, Mélanie; Odoux, Jean-François; Pissard, Aurélien; Rüger, Charlotte; Bretagnolle, Vincent

2015-11-22

European governments have banned the use of three common neonicotinoid pesticides due to insufficiently identified risks to bees. This policy decision is controversial given the absence of clear consistency between toxicity assessments of those substances in the laboratory and in the field. Although laboratory trials report deleterious effects in honeybees at trace levels, field surveys reveal no decrease in the performance of honeybee colonies in the vicinity of treated fields. Here we provide the missing link, showing that individual honeybees near thiamethoxam-treated fields do indeed disappear at a faster rate, but the impact of this is buffered by the colonies' demographic regulation response. Although we could ascertain the exposure pathway of thiamethoxam residues from treated flowers to honeybee dietary nectar, we uncovered an unexpected pervasive co-occurrence of similar concentrations of imidacloprid, another neonicotinoid normally restricted to non-entomophilous crops in the study country. Thus, its origin and transfer pathways through the succession of annual crops need be elucidated to conveniently appraise the risks of combined neonicotinoid exposures. This study reconciles the conflicting laboratory and field toxicity assessments of neonicotinoids on honeybees and further highlights the difficulty in actually detecting non-intentional effects on the field through conventional risk assessment methods. © 2015 The Author(s).

Associative Mechanosensory Conditioning of the Proboscis Extension Reflex in Honeybees

ERIC Educational Resources Information Center

Giurfa, Martin; Malun, Dagmar

2004-01-01

The present work introduces a form of associative mechanosensory conditioning of the proboscis extension reflex (PER) in honeybees. In our paradigm, harnessed honeybees learn the elemental association between mechanosensory, antennal stimulation and a reward of sucrose solution delivered to the proboscis. Thereafter, bees extend their proboscis to…

Experimental evidence that honeybees depress wild insect densities in a flowering crop

PubMed Central

Herbertsson, Lina; Rundlöf, Maj; Bommarco, Riccardo; Smith, Henrik G.

2016-01-01

While addition of managed honeybees (Apis mellifera) improves pollination of many entomophilous crops, it is unknown if it simultaneously suppresses the densities of wild insects through competition. To investigate this, we added 624 honeybee hives to 23 fields of oilseed rape (Brassica napus L.) over 2 years and made sure that the areas around 21 other fields were free from honeybee hives. We demonstrate that honeybee addition depresses the densities of wild insects (bumblebees, solitary bees, hoverflies, marchflies, other flies, and other flying and flower-visiting insects) even in a massive flower resource such as oilseed rape. The effect was independent of the complexity of the surrounding landscape, but increased with the size of the crop field, which suggests that the effect was caused by spatial displacement of wild insects. Our results have potential implications both for the pollination of crops (if displacement of wild pollinators offsets benefits achieved by adding honeybees) and for conservation of wild insects (if displacement results in negative fitness consequences). PMID:27881750

Potential distribution dataset of honeybees in Indian Ocean Islands: Case study of Zanzibar Island.

PubMed

Mwalusepo, Sizah; Muli, Eliud; Nkoba, Kiatoko; Nguku, Everlyn; Kilonzo, Joseph; Abdel-Rahman, Elfatih M; Landmann, Tobias; Fakih, Asha; Raina, Suresh

2017-10-01

Honeybees ( Apis mellifera ) are principal insect pollinators, whose worldwide distribution and abundance is known to largely depend on climatic conditions. However, the presence records dataset on potential distribution of honeybees in Indian Ocean Islands remain less documented. Presence records in shape format and probability of occurrence of honeybees with different temperature change scenarios is provided in this article across Zanzibar Island. Maximum entropy (Maxent) package was used to analyse the potential distribution of honeybees. The dataset provides information on the current and future distribution of the honey bees in Zanzibar Island. The dataset is of great importance for improving stakeholders understanding of the role of temperature change on the spatial distribution of honeybees.

Effects of sub-lethal doses of glyphosate on honeybee navigation.

PubMed

Sol Balbuena, María; Tison, Léa; Hahn, Marie-Luise; Greggers, Uwe; Menzel, Randolf; Farina, Walter M

2015-07-10

Glyphosate (GLY) is a herbicide that is widely used in agriculture for weed control. Although reports about the impact of GLY in snails, crustaceans and amphibians exist, few studies have investigated its sub-lethal effects in non-target organisms such as the honeybee Apis mellifera, the main pollen vector in commercial crops. Here, we tested whether exposure to three sub-lethal concentrations of GLY (2.5, 5 and 10 mg/L corresponding to 0.125, 0.250 and 0.500 µg/animal) affects the homeward flight path of honeybees in an open field. We performed an experiment in which forager honeybees were trained to an artificial feeder, and then captured, fed with sugar solution containing GLY traces and released from a novel site (the release site, RS) either once or twice. Their homeward trajectories were tracked using harmonic radar technology. We found that honeybees that had been fed with solution containing 10 mg/L GLY spent more time performing homeward flights than control bees or bees treated with lower GLY concentrations. They also performed more indirect homing flights. Moreover, the proportion of direct homeward flights performed after a second release at the RS increased in control bees but not in treated bees. These results suggest that, in honeybees, exposure to GLY doses commonly found in agricultural settings impairs the cognitive capacities needed to retrieve and integrate spatial information for a successful return to the hive. Therefore, honeybee navigation is affected by ingesting traces of the most widely used herbicide worldwide, with potential long-term negative consequences for colony foraging success. © 2015. Published by The Company of Biologists Ltd.

Ceropegia sandersonii Mimics Attacked Honeybees to Attract Kleptoparasitic Flies for Pollination.

PubMed

Heiduk, Annemarie; Brake, Irina; von Tschirnhaus, Michael; Göhl, Matthias; Jürgens, Andreas; Johnson, Steven D; Meve, Ulrich; Dötterl, Stefan

2016-10-24

Four to six percent of plants, distributed over different angiosperm families, entice pollinators by deception [1]. In these systems, chemical mimicry is often used as an efficient way to exploit the olfactory preferences of animals for the purpose of attracting them as pollinators [2,3]. Here, we report a very specific type of chemical mimicry of a food source. Ceropegia sandersonii (Apocynaceae), a deceptive South African plant with pitfall flowers, mimics attacked honeybees. We identified kleptoparasitic Desmometopa flies (Milichiidae) as the main pollinators of C. sandersonii. These flies are well known to feed on honeybees that are eaten by spiders, which we thus predicted as the model chemically mimicked by the plant. Indeed, we found that the floral scent of C. sandersonii is comparable to volatiles released from honeybees when under simulated attack. Moreover, many of these shared compounds elicited physiological responses in antennae of pollinating Desmometopa flies. A mixture of four compounds-geraniol, 2-heptanone, 2-nonanol, and (E)-2-octen-1-yl acetate-was highly attractive to the flies. We conclude that C. sandersonii is specialized on kleptoparasitic fly pollinators by deploying volatiles linked to the flies' food source, i.e., attacked and/or freshly killed honeybees. The blend of compounds emitted by C. sandersonii is unusual among flowering plants and lures kleptoparasitic flies into the trap flowers. This study describes a new example of how a plant can achieve pollination through chemical mimicry of the food sources of adult carnivorous animals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Movement Analysis of Flexion and Extension of Honeybee Abdomen Based on an Adaptive Segmented Structure

PubMed Central

Zhao, Jieliang; Wu, Jianing; Yan, Shaoze

2015-01-01

Honeybees (Apis mellifera) curl their abdomens for daily rhythmic activities. Prior to determining this fact, people have concluded that honeybees could curl their abdomen casually. However, an intriguing but less studied feature is the possible unidirectional abdominal deformation in free-flying honeybees. A high-speed video camera was used to capture the curling and to analyze the changes in the arc length of the honeybee abdomen not only in free-flying mode but also in the fixed sample. Frozen sections and environment scanning electron microscope were used to investigate the microstructure and motion principle of honeybee abdomen and to explore the physical structure restricting its curling. An adaptive segmented structure, especially the folded intersegmental membrane (FIM), plays a dominant role in the flexion and extension of the abdomen. The structural features of FIM were utilized to mimic and exhibit movement restriction on honeybee abdomen. Combining experimental analysis and theoretical demonstration, a unidirectional bending mechanism of honeybee abdomen was revealed. Through this finding, a new perspective for aerospace vehicle design can be imitated. PMID:26223946

Rare royal families in honeybees, Apis mellifera

NASA Astrophysics Data System (ADS)

Moritz, Robin F. A.; Lattorff, H. Michael G.; Neumann, Peter; Kraus, F. Bernhard; Radloff, Sarah E.; Hepburn, H. Randall

2005-10-01

The queen is the dominant female in the honeybee colony, Apis mellifera, and controls reproduction. Queen larvae are selected by the workers and are fed a special diet (royal jelly), which determines caste. Because queens mate with many males a large number of subfamilies coexist in the colony. As a consequence, there is a considerable potential for conflict among the subfamilies over queen rearing. Here we show that honeybee queens are not reared at random but are preferentially reared from rare “royal” subfamilies, which have extremely low frequencies in the colony's worker force but a high frequency in the queens reared.

Antimicrobial activity of plant extracts against the honeybee pathogens, Paenibacillus larvae and Ascosphaera apis and their topical toxicity to Apis mellifera adults.

PubMed

Chaimanee, V; Thongtue, U; Sornmai, N; Songsri, S; Pettis, J S

2017-11-01

To explore alternative nonchemical control measures against two honeybee pathogens, Paenibacillus larvae and Ascosphaera apis, 37 plant species were screened for antimicrobial activity. The activity of selected plant extracts was screened using an in vitro disc diffusion assay and the minimal inhibitory concentration (MIC) was determined by the broth microdilution method. The results showed that 36 plant extracts had some antibacterial activity on P. larvae by disc diffusion assay. Chromolaena odorata showed the greatest antibacterial activity against P. larvae (MIC 16-64 μg ml -1 ). Of the 37 tested plants, only seven species, Amomum krervanh, Allium sativum, Cinnamomum sp., Piper betle, Piper ribesioides, Piper sarmentosum and Syzygium aromaticum had inhibitory effects on A. apis (MICs of 32-64 μg ml -1 ). The results demonstrated that promising plant extracts were not toxic to adult bees at the concentrations used in this study. The results demonstrate the potential antimicrobial activity of natural products against honeybee diseases caused by P. larvae and A. apis. Chromolaena odorata in particular showed high bioactivity against P. larvae. Further study is recommended to develop these nonchemical treatments against American foulbrood and chalkbrood in honeybees. This work proposes new natural products for the control of American foulbrood and chalkbrood in honeybees. © 2017 The Society for Applied Microbiology.

Experimental evidence that honeybees depress wild insect densities in a flowering crop.

PubMed

Lindström, Sandra A M; Herbertsson, Lina; Rundlöf, Maj; Bommarco, Riccardo; Smith, Henrik G

2016-11-30

While addition of managed honeybees (Apis mellifera) improves pollination of many entomophilous crops, it is unknown if it simultaneously suppresses the densities of wild insects through competition. To investigate this, we added 624 honeybee hives to 23 fields of oilseed rape (Brassica napus L.) over 2 years and made sure that the areas around 21 other fields were free from honeybee hives. We demonstrate that honeybee addition depresses the densities of wild insects (bumblebees, solitary bees, hoverflies, marchflies, other flies, and other flying and flower-visiting insects) even in a massive flower resource such as oilseed rape. The effect was independent of the complexity of the surrounding landscape, but increased with the size of the crop field, which suggests that the effect was caused by spatial displacement of wild insects. Our results have potential implications both for the pollination of crops (if displacement of wild pollinators offsets benefits achieved by adding honeybees) and for conservation of wild insects (if displacement results in negative fitness consequences). © 2016 The Author(s).

Energy saving strategies of honeybees in dipping nectar.

PubMed

Wu, Jianing; Yang, Heng; Yan, Shaoze

2015-10-08

The honeybee's drinking process has generally been simplified because of its high speed and small scale. In this study, we clearly observed the drinking cycle of the Italian honeybee using a specially designed high-speed camera system. We analysed the pattern of glossal hair erection and the movement kinematics of the protracting tongue (glossa). Results showed that the honeybee used two special protraction strategies to save energy. First, the glossal hairs remain adpressed until the end of the protraction, which indicates that the hydraulic resistance is reduced to less than 1/3 of that in the case if the hairs remain erect. Second, the glossa protracts with a specific velocity profile and we quantitatively demonstrated that this moving strategy helps reduce the total energy needed for protraction compared with the typical form of protraction with constant acceleration and deceleration. These findings suggest effective methods to optimise the control policies employed by next-generation microfluidic pumps.

Comparative psychophysics of bumblebee and honeybee colour discrimination and object detection.

PubMed

Dyer, Adrian G; Spaethe, Johannes; Prack, Sabina

2008-07-01

Bumblebee (Bombus terrestris) discrimination of targets with broadband reflectance spectra was tested using simultaneous viewing conditions, enabling an accurate determination of the perceptual limit of colour discrimination excluding confounds from memory coding (experiment 1). The level of colour discrimination in bumblebees, and honeybees (Apis mellifera) (based upon previous observations), exceeds predictions of models considering receptor noise in the honeybee. Bumblebee and honeybee photoreceptors are similar in spectral shape and spacing, but bumblebees exhibit significantly poorer colour discrimination in behavioural tests, suggesting possible differences in spatial or temporal signal processing. Detection of stimuli in a Y-maze was evaluated for bumblebees (experiment 2) and honeybees (experiment 3). Honeybees detected stimuli containing both green-receptor-contrast and colour contrast at a visual angle of approximately 5 degrees , whilst stimuli that contained only colour contrast were only detected at a visual angle of 15 degrees . Bumblebees were able to detect these stimuli at a visual angle of 2.3 degrees and 2.7 degrees , respectively. A comparison of the experiments suggests a tradeoff between colour discrimination and colour detection in these two species, limited by the need to pool colour signals to overcome receptor noise. We discuss the colour processing differences and possible adaptations to specific ecological habitats.

Honeybee economics: optimisation of foraging in a variable world.

PubMed

Stabentheiner, Anton; Kovac, Helmut

2016-06-20

In honeybees fast and efficient exploitation of nectar and pollen sources is achieved by persistent endothermy throughout the foraging cycle, which means extremely high energy costs. The need for food promotes maximisation of the intake rate, and the high costs call for energetic optimisation. Experiments on how honeybees resolve this conflict have to consider that foraging takes place in a variable environment concerning microclimate and food quality and availability. Here we report, in simultaneous measurements of energy costs, gains, and intake rate and efficiency, how honeybee foragers manage this challenge in their highly variable environment. If possible, during unlimited sucrose flow, they follow an 'investment-guided' ('time is honey') economic strategy promising increased returns. They maximise net intake rate by investing both own heat production and solar heat to increase body temperature to a level which guarantees a high suction velocity. They switch to an 'economizing' ('save the honey') optimisation of energetic efficiency if the intake rate is restricted by the food source when an increased body temperature would not guarantee a high intake rate. With this flexible and graded change between economic strategies honeybees can do both maximise colony intake rate and optimise foraging efficiency in reaction to environmental variation.

Honeybees Prefer to Steer on a Smooth Wall With Tetrapod Gaits

PubMed Central

Zhao, Jieliang; Zhu, Fei; Yan, Shaoze

2018-01-01

Abstract Insects are well equipped in walking on complex three-dimensional terrain, allowing them to overcome obstacles or catch prey. However, the gait transition for insects steering on a wall remains unexplored. Here, we find that honeybees adopted a tetrapod gait to change direction when climbing a wall. On the contrary to the common tripod gait, honeybees propel their body forward by synchronously stepping with both middle legs and then both front legs. This process ensures the angle of the central axis of the honeybee to be consistent with the crawling direction. Interestingly, when running in an alternating tripod gait, the central axis of honeybee sways around the center of mass under alternating tripod gait to maintain stability. Experimental results show that tripod, tetrapod, and random gaits result in the amazing consensus harmony on the climbing speed and gait stability, whether climbing on a smooth wall or walking on smooth ground. PMID:29722862

Visual generalization in honeybees: evidence of peak shift in color discrimination.

PubMed

Martínez-Harms, J; Márquez, N; Menzel, R; Vorobyev, M

2014-04-01

In the present study, we investigated color generalization in the honeybee Apis mellifera after differential conditioning. In particular, we evaluated the effect of varying the position of a novel color along a perceptual continuum relative to familiar colors on response biases. Honeybee foragers were differentially trained to discriminate between rewarded (S+) and unrewarded (S-) colors and tested on responses toward the former S+ when presented against a novel color. A color space based on the receptor noise-limited model was used to evaluate the relationship between colors and to characterize a perceptual continuum. When S+ was tested against a novel color occupying a locus in the color space located in the same direction from S- as S+, but further away, the bees shifted their stronger response away from S- toward the novel color. These results reveal the occurrence of peak shift in the color vision of honeybees and indicate that honeybees can learn color stimuli in relational terms based on chromatic perceptual differences.

Hygienic and grooming behaviors in African and European honeybees-New damage categories in Varroa destructor

USDA-ARS?s Scientific Manuscript database

Varroa destructor is an ectoparasitic pest of honeybees, and a threat to the survival of the apiculture industry. Several studies have shown that unlike European honeybees, African honeybee populations appear to be minimally affected when attacked by this mite. However, little is known about the und...

Collective fluid mechanics of honeybee nest ventilation

NASA Astrophysics Data System (ADS)

Gravish, Nick; Combes, Stacey; Wood, Robert J.; Peters, Jacob

2014-11-01

Honeybees thermoregulate their brood in the warm summer months by collectively fanning their wings and creating air flow through the nest. During nest ventilation workers flap their wings in close proximity in which wings continuously operate in unsteady oncoming flows (i.e. the wake of neighboring worker bees) and near the ground. The fluid mechanics of this collective aerodynamic phenomena are unstudied and may play an important role in the physiology of colony life. We have performed field and laboratory observations of the nest ventilation wing kinematics and air flow generated by individuals and groups of honeybee workers. Inspired from these field observations we describe here a robotic model system to study collective flapping wing aerodynamics. We microfabricate arrays of 1.4 cm long flapping wings and observe the air flow generated by arrays of two or more fanning robotic wings. We vary phase, frequency, and separation distance among wings and find that net output flow is enhanced when wings operate at the appropriate phase-distance relationship to catch shed vortices from neighboring wings. These results suggest that by varying position within the fanning array honeybee workers may benefit from collective aerodynamic interactions during nest ventilation.

Visual attention in a complex search task differs between honeybees and bumblebees.

PubMed

Morawetz, Linde; Spaethe, Johannes

2012-07-15

Mechanisms of spatial attention are used when the amount of gathered information exceeds processing capacity. Such mechanisms have been proposed in bees, but have not yet been experimentally demonstrated. We provide evidence that selective attention influences the foraging performance of two social bee species, the honeybee Apis mellifera and the bumblebee Bombus terrestris. Visual search tasks, originally developed for application in human psychology, were adapted for behavioural experiments on bees. We examined the impact of distracting visual information on search performance, which we measured as error rate and decision time. We found that bumblebees were significantly less affected by distracting objects than honeybees. Based on the results, we conclude that the search mechanism in honeybees is serial like, whereas in bumblebees it shows the characteristics of a restricted parallel-like search. Furthermore, the bees differed in their strategy to solve the speed-accuracy trade-off. Whereas bumblebees displayed slow but correct decision-making, honeybees exhibited fast and inaccurate decision-making. We propose two neuronal mechanisms of visual information processing that account for the different responses between honeybees and bumblebees, and we correlate species-specific features of the search behaviour to differences in habitat and life history.

Dancing to different tunes: heterospecific deciphering of the honeybee waggle dance

NASA Astrophysics Data System (ADS)

Tan, K.; Yang, M. X.; Radloff, S. E.; Hepburn, H. R.; Zhang, Z. Y.; Luo, L. J.; Li, H.

2008-12-01

Although the structure of the dance language is very similar among species of honeybees, communication of the distance component of the message varies both intraspecifically and interspecifically. However, it is not known whether different honeybee species would attend interspecific waggle dances and, if so, whether they can decipher such dances. Using mixed-species colonies of Apis cerana and Apis mellifera, we show that, despite internal differences in the structure of the waggle dances of foragers, both species attend, and act on the information encoded in each other’s waggle dances but with limited accuracy. These observations indicate that direction and distance communication pre-date speciation in honeybees.

Fertility and reproductive rate of Varroa mite, Varroa destructor, in native and exotic honeybee, Apis mellifera L., colonies under Saudi Arabia conditions.

PubMed

Alattal, Yehya; AlGhamdi, Ahmad; Single, Arif; Ansari, Mohammad Javed; Alkathiri, Hussien

2017-07-01

Varroa mite is the most destructive pest to bee colonies worldwide. In Saudi Arabia, preliminary data indicated high infestation levels in the exotic honeybee colonies; such as Apis mellifera carnica and Apis mellifera ligustica , compared to native honeybee subspecies Apis mellifera jemenitica , which may imply higher tolerance to Varroasis . In this study, fertility and reproductive rate of Varroa mite, Varroa destructor , in capped brood cells of the native honeybee subspecies were investigated and compared with an exotic honeybee subspecies, A. m . carnica . Mite fertility was almost alike (87.5% and 89.4%) in the native and craniolan colonies respectively. Similarly, results did not show significant differences in reproduction rate between both subspecies ( F  = 0.66, Pr >  F  = 0.42). Number of adult Varroa daughters per fertile mother mite was 2.0 and 2.1 for native and craniolan honeybee subspecies respectively. This may indicate that mechanisms of keeping low infestation rates in the native honeybee colonies are not associated with Varroa reproduction. Therefore, potential factors of keeping lower Varroa infestation rates in native honey bee subspecies should be further investigated.

Impact of Chronic Neonicotinoid Exposure on Honeybee Colony Performance and Queen Supersedure

PubMed Central

Sandrock, Christoph; Tanadini, Matteo; Tanadini, Lorenzo G.; Fauser-Misslin, Aline; Potts, Simon G.; Neumann, Peter

2014-01-01

Background Honeybees provide economically and ecologically vital pollination services to crops and wild plants. During the last decade elevated colony losses have been documented in Europe and North America. Despite growing consensus on the involvement of multiple causal factors, the underlying interactions impacting on honeybee health and colony failure are not fully resolved. Parasites and pathogens are among the main candidates, but sublethal exposure to widespread agricultural pesticides may also affect bees. Methodology/Principal Findings To investigate effects of sublethal dietary neonicotinoid exposure on honeybee colony performance, a fully crossed experimental design was implemented using 24 colonies, including sister-queens from two different strains, and experimental in-hive pollen feeding with or without environmentally relevant concentrations of thiamethoxam and clothianidin. Honeybee colonies chronically exposed to both neonicotinoids over two brood cycles exhibited decreased performance in the short-term resulting in declining numbers of adult bees (−28%) and brood (−13%), as well as a reduction in honey production (−29%) and pollen collections (−19%), but colonies recovered in the medium-term and overwintered successfully. However, significantly decelerated growth of neonicotinoid-exposed colonies during the following spring was associated with queen failure, revealing previously undocumented long-term impacts of neonicotinoids: queen supersedure was observed for 60% of the neonicotinoid-exposed colonies within a one year period, but not for control colonies. Linked to this, neonicotinoid exposure was significantly associated with a reduced propensity to swarm during the next spring. Both short-term and long-term effects of neonicotinoids on colony performance were significantly influenced by the honeybees’ genetic background. Conclusions/Significance Sublethal neonicotinoid exposure did not provoke increased winter losses. Yet

Mouthpart grooming behavior in honeybees: Kinematics and sectionalized friction between foreleg tarsi and proboscises.

PubMed

Linghu, Zelin; Wu, Jianing; Wang, Changlong; Yan, Shaoze

2015-11-01

The mouthpart of a honeybee is prone to contamination by granular particles such as pollen or dirt from the field. To clean the contaminated mouthparts, a honeybee swings its foreleg tarsi forward and backward to brush the proboscis continuously, sweeping the contaminant from the surfaces of the labial palpi, galeae, and bushy haired tongue (glossa). This grooming behavior has been documented but the dynamic characteristics therein have not been investigated yet. We quantified the grooming behavior of a honeybee from the perspective of kinematic and tribological properties. We captured high-speed videos that recorded the mouthpart grooming patterns of honeybees from the front and side views and measured the friction on the grooming surfaces using a precision dynamometer. During grooming, a honeybee first positions the mouthpart and then places a pair of foreleg tarsi to the tubular-folded galea. The tarsi press the galea and labial palpi and slide downward while keeping close contact with the galea. Then, the hairy glossa stretches out of the temporary tube with the glossa setae erected. The tarsi slowly slide down when grooming the glossa. In the return stroke of grooming, the foreleg tarsi detach from the mouthpart and retreat swiftly. Friction analysis shows that the honeybees can coordinate the velocity of the foreleg tarsi to the sectionalized tribological property of the tarsus-mouthpart interface. The specific grooming pattern enables honeybees to save energy and resist wear, resulting in a possible highly evolved grooming strategy. These findings lead to further understanding of the honeybee's grooming behavior facilitated by the special motion kinematics and friction characteristics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Single Honeybee Silk Protein Mimics Properties of Multi-Protein Silk

PubMed Central

Sutherland, Tara D.; Church, Jeffrey S.; Hu, Xiao; Huson, Mickey G.; Kaplan, David L.; Weisman, Sarah

2011-01-01

Honeybee silk is composed of four fibrous proteins that, unlike other silks, are readily synthesized at full-length and high yield. The four silk genes have been conserved for over 150 million years in all investigated bee, ant and hornet species, implying a distinct functional role for each protein. However, the amino acid composition and molecular architecture of the proteins are similar, suggesting functional redundancy. In this study we compare materials generated from a single honeybee silk protein to materials containing all four recombinant proteins or to natural honeybee silk. We analyse solution conformation by dynamic light scattering and circular dichroism, solid state structure by Fourier Transform Infrared spectroscopy and Raman spectroscopy, and fiber tensile properties by stress-strain analysis. The results demonstrate that fibers artificially generated from a single recombinant silk protein can reproduce the structural and mechanical properties of the natural silk. The importance of the four protein complex found in natural silk may lie in biological silk storage or hierarchical self-assembly. The finding that the functional properties of the mature material can be achieved with a single protein greatly simplifies the route to production for artificial honeybee silk. PMID:21311767

Functional characterization of transmembrane adenylyl cyclases from the honeybee brain.

PubMed

Balfanz, Sabine; Ehling, Petra; Wachten, Sebastian; Jordan, Nadine; Erber, Joachim; Mujagic, Samir; Baumann, Arnd

2012-06-01

The second messenger cAMP has a pivotal role in animals' physiology and behavior. Intracellular concentrations of cAMP are balanced by cAMP-synthesizing adenylyl cyclases (ACs) and cAMP-cleaving phosphodiesterases. Knowledge about ACs in the honeybee (Apis mellifera) is rather limited and only an ortholog of the vertebrate AC3 isoform has been functionally characterized, so far. Employing bioinformatics and functional expression we characterized two additional honeybee genes encoding membrane-bound (tm)ACs. The proteins were designated AmAC2t and AmAC8. Unlike the common structure of tmACs, AmAC2t lacks the first transmembrane domain. Despite this unusual topography, AmAC2t-activity could be stimulated by norepinephrine and NKH477 with EC(50s) of 0.07 μM and 3 μM. Both ligands stimulated AmAC8 with EC(50s) of 0.24 μM and 3.1 μM. In brain cryosections, intensive staining of mushroom bodies was observed with specific antibodies against AmAC8, an expression pattern highly reminiscent of the Drosophila rutabaga AC. In a current release of the honeybee genome database we identified three additional tmAC- and one soluble AC-encoding gene. These results suggest that (1) the AC-gene family in honeybees is comparably large as in other species, and (2) based on the restricted expression of AmAC8 in mushroom bodies, this enzyme might serve important functions in honeybee behavior. Copyright © 2012 Elsevier Ltd. All rights reserved.

Drag reduction effects facilitated by microridges inside the mouthparts of honeybee workers and drones.

PubMed

Li, Chu-Chu; Wu, Jia-Ning; Yang, Yun-Qiang; Zhu, Ren-Gao; Yan, Shao-Ze

2016-01-21

The mouthpart of a honeybee is a natural well-designed micropump that uses a reciprocating glossa through a temporary tube comprising a pair of galeae and labial palpi for loading nectar. The shapes and sizes of mouthparts differ among castes of honeybees, but the diversities of the functional microstructures inside the mouthparts of honeybee workers and drones remain poorly understood. Through scanning electron microscopy, we found the dimensional difference of uniformly distributed microridges on the inner galeae walls of Apis mellifera ligustica workers and drones. Subsequently, we recorded the feeding process of live honeybees by using a specially designed high-speed camera system. Considering the microridges and kinematics of the glossa, we constructed a hydrodynamic model to calculate the friction coefficient of the mouthpart. In addition, we test the drag reduction through the dimensional variations of the microridges on the inner walls of mouthparts. Theoretical estimations of the friction coefficient with respect to dipping frequency show that inner microridges can reduce friction during the feeding process of honeybees. The effects of drag reduction regulated by specific microridges were then compared. The friction coefficients of the workers and drones were found to be 0.011±0.007 (mean±s.d.) and 0.045±0.010, respectively. These results indicate that the mouthparts of workers are more capable of drag reduction compared with those of drones. The difference was analyzed by comparing the foraging behavior of the workers and drones. Workers are equipped with well-developed hypopharyngeal, and their dipping frequency is higher than that of drones. Our research establishes a critical link between microridge dimensions and drag reduction capability during the nectar feeding of honeybees. Our results reveal that microridges inside the mouthparts of honeybee workers and drones reflect the caste-related life cycles of honeybees. Copyright © 2015 Elsevier Ltd

Laurel leaf extracts for honeybee pest and disease management: antimicrobial, microsporicidal, and acaricidal activity.

PubMed

Damiani, Natalia; Fernández, Natalia J; Porrini, Martín P; Gende, Liesel B; Álvarez, Estefanía; Buffa, Franco; Brasesco, Constanza; Maggi, Matías D; Marcangeli, Jorge A; Eguaras, Martín J

2014-02-01

A diverse set of parasites and pathogens affects productivity and survival of Apis mellifera honeybees. In beekeeping, traditional control by antibiotics and molecules of synthesis has caused problems with contamination and resistant pathogens. In this research, different Laurus nobilis extracts are tested against the main honeybee pests through an integrated point of view. In vivo effects on bee survival are also evaluated. The ethanol extract showed minimal inhibitory concentration (MIC) values of 208 to 416 μg/mL, having the best antimicrobial effect on Paenibacillus larvae among all substances tested. Similarly, this leaf extract showed a significant antiparasitic activity on Varroa destructor, killing 50 % of mites 24 h after a 30-s exposure, and on Nosema ceranae, inhibiting the spore development in the midgut of adult bees ingesting 1 × 10(4) μg/mL of extract solution. Both ethanol extract and volatile extracts (essential oil, hydrolate, and its main component) did not cause lethal effects on adult honeybees. Thus, the absence of topical and oral toxicity of the ethanol extract on bees and the strong antimicrobial, microsporicidal, and miticidal effects registered in this study place this laurel extract as a promising integrated treatment of bee diseases and stimulates the search for other bioactive phytochemicals from plants.

Do the honeybee pathogens Nosema ceranae and deformed wing virus act synergistically?

PubMed Central

Martin, Stephen J; Hardy, Jennifer; Villalobos, Ethel; Martín-Hernández, Raquel; Nikaido, Scott; Higes, Mariano

2013-01-01

The honeybee pathogens Nosema ceranae and deformed wing virus (DWV) cause the collapse of honeybee colonies. Therefore, it is plausible that these two pathogens act synergistically to increase colony losses, since N. ceranae causes damage to the mid-gut epithelial ventricular cells and actively suppresses the honeybees’ immune response, either of which could increase the virulence of viral pathogens within the bee. To test this hypothesis we exploited 322 Hawaiian honeybee colonies for which DWV prevalence and load is known. We determined via PCR that N. ceranae was present in 89–95% of these colonies, with no Nosema apis being detected. We found no significant difference in spore counts in colonies infected with DWV and those in which DWV was not detected, either on any of the four islands or across the entire honeybee population. Furthermore, no significant correlation between DWV loads (ΔCT levels) and N. ceranae spore counts was found, so these two pathogens are not acting synergistically. Although the Hawaiian honeybees have the highest known prevalence of N. ceranae in the world, with average number of spores been 2.7 million per bee, no acute Nosema related problems i.e. large-scale colony deaths, have been reported by Hawaiian beekeepers. PMID:23864563

Honeybee Odometry: Performance in Varying Natural Terrain

PubMed Central

Tautz, Juergen; Zhang, Shaowu; Spaethe, Johannes; Brockmann, Axel; Si, Aung

2004-01-01

Recent studies have shown that honeybees flying through short, narrow tunnels with visually textured walls perform waggle dances that indicate a much greater flight distance than that actually flown. These studies suggest that the bee's “odometer” is driven by the optic flow (image motion) that is experienced during flight. One might therefore expect that, when bees fly to a food source through a varying outdoor landscape, their waggle dances would depend upon the nature of the terrain experienced en route. We trained honeybees to visit feeders positioned along two routes, each 580 m long. One route was exclusively over land. The other was initially over land, then over water and, finally, again over land. Flight over water resulted in a significantly flatter slope of the waggle-duration versus distance regression, compared to flight over land. The mean visual contrast of the scenes was significantly greater over land than over water. The results reveal that, in outdoor flight, the honeybee's odometer does not run at a constant rate; rather, the rate depends upon the properties of the terrain. The bee's perception of distance flown is therefore not absolute, but scene-dependent. These findings raise important and interesting questions about how these animals navigate reliably. PMID:15252454

Mating flights select for symmetry in honeybee drones ( Apis mellifera)

NASA Astrophysics Data System (ADS)

Jaffé, Rodolfo; Moritz, Robin F. A.

2010-03-01

Males of the honeybee ( Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen’s visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.

Mating flights select for symmetry in honeybee drones (Apis mellifera).

PubMed

Jaffé, Rodolfo; Moritz, Robin F A

2010-03-01

Males of the honeybee (Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen's visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.

Scientists train honeybees to detect explosives

ScienceCinema

None

2017-12-09

Members of the Los Alamos National Laboratory Stealthy Insect Sensor Project team have been able to harness the honeybee's exceptional olfactory sense by using the bees' natural reaction to nectar, a proboscis extension reflex (sticking out their tongue)

Scientists train honeybees to detect explosives

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2008-03-21

Members of the Los Alamos National Laboratory Stealthy Insect Sensor Project team have been able to harness the honeybee's exceptional olfactory sense by using the bees' natural reaction to nectar, a proboscis extension reflex (sticking out their tongue)

The dance of the honeybee: how do honeybees dance to transfer food information effectively?

PubMed

Okada, R; Ikeno, H; Sasayama, Noriko; Aonuma, H; Kurabayashi, D; Ito, E

2008-01-01

A honeybee informs her nestmates of the location of a flower she has visited by a unique behavior called a "waggle dance." On a vertical comb, the direction of the waggle run relative to gravity indicates the direction to the food source relative to the sun in the field, and the duration of the waggle run indicates the distance to the food source. To determine the detailed biological features of the waggle dance, we observed worker honeybee behavior in the field. Video analysis showed that the bee does not dance in a single or random place in the hive but waggled several times in one place and then several times in another. It also showed that the information of the waggle dance contains a substantial margin of error. Angle and duration of waggle runs varied from run to run, with the range of +/-15 degrees and +/-15%, respectively, even in a series of waggle dances of a single individual. We also found that most dance followers that listen to the waggle dance left the dancer after one or two sessions of listening.

[Assessment of hypersensitivity to honey-bee venom in beekeepers by skin tests].

PubMed

Becerril-Ángeles, Martín; Núñez-Velázquez, Marco; Marín-Martínez, Javier

2013-01-01

Beekeepers are exposed to frequent honey-bee stings, and have the risk to develop hypersensitivity to bee venom, but long-term exposure can induce immune tolerance in them. Up to 30% of beekeepers show positive skin tests with honey-bee venom. The prevalence of systemic reactions to bee stings in beekeepers is from 14% to 42%. To know the prevalence of hypersensitivity to honeybee venom in Mexican beekeepers and non-beekeepers by the use of skin tests. A group of 139 beekeepers and a group of 60 non-beekeeper volunteers had a history and physical related to age, sex, family and personal atopic history and time of exposure to bee stings. Both groups received intradermal skin tests with honey-bee venom, 0.1 mcg/mL and 1 mcg/mL, and histamine sulphate 0.1 mg/mL and Evans solution as controls. The skin tests results of both groups were compared by chi-squared test. Of the group of beekeepers, 116 were men (83%) and 23 women, average age was 39.3 years, had atopic family history 28% and personal atopy 13%, average time of exposure to bee stings was 10.9 years, skin tests with honey-bee venom were positive in 16.5% and 11% at 1 mcg/mL and 0.1 mcg/mL, respectively. In the non-beekeepers group venom skin tests were positive in 13.3% and 6.7% at 1 mcg/mL and 0.1 mcg/mL. We did not find significant differences between the two venom concentrations tested in both groups, neither in the number of positive skin tests between the two groups. We found hypersensivity to honey-bee venom slightly higher in the beekeepers than in the group apparently not exposed. Both honey-bee venom concentrations used did not show difference in the results of the skin tests. The similarity of skin tests positivity between both groups could be explained by immune tolerance due to continued exposure of beekeepers.

Towards a systems approach for understanding honeybee decline: a stocktaking and synthesis of existing models.

PubMed

Becher, Matthias A; Osborne, Juliet L; Thorbek, Pernille; Kennedy, Peter J; Grimm, Volker

2013-08-01

The health of managed and wild honeybee colonies appears to have declined substantially in Europe and the United States over the last decade. Sustainability of honeybee colonies is important not only for honey production, but also for pollination of crops and wild plants alongside other insect pollinators. A combination of causal factors, including parasites, pathogens, land use changes and pesticide usage, are cited as responsible for the increased colony mortality.However, despite detailed knowledge of the behaviour of honeybees and their colonies, there are no suitable tools to explore the resilience mechanisms of this complex system under stress. Empirically testing all combinations of stressors in a systematic fashion is not feasible. We therefore suggest a cross-level systems approach, based on mechanistic modelling, to investigate the impacts of (and interactions between) colony and land management.We review existing honeybee models that are relevant to examining the effects of different stressors on colony growth and survival. Most of these models describe honeybee colony dynamics, foraging behaviour or honeybee - varroa mite - virus interactions.We found that many, but not all, processes within honeybee colonies, epidemiology and foraging are well understood and described in the models, but there is no model that couples in-hive dynamics and pathology with foraging dynamics in realistic landscapes. Synthesis and applications . We describe how a new integrated model could be built to simulate multifactorial impacts on the honeybee colony system, using building blocks from the reviewed models. The development of such a tool would not only highlight empirical research priorities but also provide an important forecasting tool for policy makers and beekeepers, and we list examples of relevant applications to bee disease and landscape management decisions.

The prevalence of the honeybee brood pathogens Ascosphaera apis, Paenibacillus larvae and Melissococcus plutonius in Spanish apiaries determined with a new multiplex PCR assay

PubMed Central

Garrido-Bailón, Encarna; Higes, Mariano; Martínez-Salvador, Amparo; Antúnez, Karina; Botías, Cristina; Meana, Aránzazu; Prieto, Lourdes; Martín-Hernández, Raquel

2013-01-01

The microorganisms Ascosphaera apis, Paenibacillus larvae and Melissococcus plutonius are the three most important pathogens that affect honeybee brood. The aim of the present study was to evaluate the prevalence of these pathogens in honeybee colonies and to elucidate their role in the honeybee colony losses in Spain. In order to get it, a multiplex polymerase chain reaction (PCR) assay was developed to simultaneously amplify the16S ribosomal ribonucleic acid (rRNA) gene of P. larvae and M. plutonius, and the 5.8S rRNA gene of A. apis. The multiplex PCR assay provides a quick and specific tool that successfully detected the three infectious pathogens (P. larvae, M. plutonius and A. apis) in brood and adult honeybee samples without the need for microbiological culture. This technique was then used to evaluate the prevalence of these pathogens in Spanish honeybee colonies in 2006 and 2007, revealing our results a low prevalence of these pathogens in most of the geographic areas studied. PMID:23919248

Behavioral genomics of honeybee foraging and nest defense

NASA Astrophysics Data System (ADS)

Hunt, Greg J.; Amdam, Gro V.; Schlipalius, David; Emore, Christine; Sardesai, Nagesh; Williams, Christie E.; Rueppell, Olav; Guzmán-Novoa, Ernesto; Arechavaleta-Velasco, Miguel; Chandra, Sathees; Fondrk, M. Kim; Beye, Martin; Page, Robert E.

2007-04-01

The honeybee has been the most important insect species for study of social behavior. The recently released draft genomic sequence for the bee will accelerate honeybee behavioral genetics. Although we lack sufficient tools to manipulate this genome easily, quantitative trait loci (QTLs) that influence natural variation in behavior have been identified and tested for their effects on correlated behavioral traits. We review what is known about the genetics and physiology of two behavioral traits in honeybees, foraging specialization (pollen versus nectar), and defensive behavior, and present evidence that map-based cloning of genes is more feasible in the bee than in other metazoans. We also present bioinformatic analyses of candidate genes within QTL confidence intervals (CIs). The high recombination rate of the bee made it possible to narrow the search to regions containing only 17-61 predicted peptides for each QTL, although CIs covered large genetic distances. Knowledge of correlated behavioral traits, comparative bioinformatics, and expression assays facilitated evaluation of candidate genes. An overrepresentation of genes involved in ovarian development and insulin-like signaling components within pollen foraging QTL regions suggests that an ancestral reproductive gene network was co-opted during the evolution of foraging specialization. The major QTL influencing defensive/aggressive behavior contains orthologs of genes involved in central nervous system activity and neurogenesis. Candidates at the other two defensive-behavior QTLs include modulators of sensory signaling ( Am5HT 7 serotonin receptor, AmArr4 arrestin, and GABA-B-R1 receptor). These studies are the first step in linking natural variation in honeybee social behavior to the identification of underlying genes.

[Determination of 10-HDA in honeybee body by HPLC].

PubMed

Fan, H; He, C; Han, H

1999-05-01

In the present work we found that in the honeybee body there exists an unsaturated fatty acid, trans-10-hydroxy-2-decenoic acid (10-HDA), which was known only to be present in royal jelly. We established the analytical method of 10-HDA in honeybee body by HPLC and simplified the extraction method of 10-HDA. In the optimum conditions the linear range of detection was 10-1,000 ng, the correlation coefficient was 0.9998, the recovery was 96.5%-99.2% and the detectable limit was 0.53 microgram/g.

Molecular mechanisms underlying formation of long-term reward memories and extinction memories in the honeybee (Apis mellifera)

PubMed Central

2014-01-01

The honeybee (Apis mellifera) has long served as an invertebrate model organism for reward learning and memory research. Its capacity for learning and memory formation is rooted in the ecological need to efficiently collect nectar and pollen during summer to ensure survival of the hive during winter. Foraging bees learn to associate a flower's characteristic features with a reward in a way that resembles olfactory appetitive classical conditioning, a learning paradigm that is used to study mechanisms underlying learning and memory formation in the honeybee. Due to a plethora of studies on appetitive classical conditioning and phenomena related to it, the honeybee is one of the best characterized invertebrate model organisms from a learning psychological point of view. Moreover, classical conditioning and associated behavioral phenomena are surprisingly similar in honeybees and vertebrates, suggesting a convergence of underlying neuronal processes, including the molecular mechanisms that contribute to them. Here I review current thinking on the molecular mechanisms underlying long-term memory (LTM) formation in honeybees following classical conditioning and extinction, demonstrating that an in-depth analysis of the molecular mechanisms of classical conditioning in honeybees might add to our understanding of associative learning in honeybees and vertebrates. PMID:25225299

Towards a systems approach for understanding honeybee decline: a stocktaking and synthesis of existing models

PubMed Central

Becher, Matthias A; Osborne, Juliet L; Thorbek, Pernille; Kennedy, Peter J; Grimm, Volker

2013-01-01

The health of managed and wild honeybee colonies appears to have declined substantially in Europe and the United States over the last decade. Sustainability of honeybee colonies is important not only for honey production, but also for pollination of crops and wild plants alongside other insect pollinators. A combination of causal factors, including parasites, pathogens, land use changes and pesticide usage, are cited as responsible for the increased colony mortality. However, despite detailed knowledge of the behaviour of honeybees and their colonies, there are no suitable tools to explore the resilience mechanisms of this complex system under stress. Empirically testing all combinations of stressors in a systematic fashion is not feasible. We therefore suggest a cross-level systems approach, based on mechanistic modelling, to investigate the impacts of (and interactions between) colony and land management. We review existing honeybee models that are relevant to examining the effects of different stressors on colony growth and survival. Most of these models describe honeybee colony dynamics, foraging behaviour or honeybee – varroa mite – virus interactions. We found that many, but not all, processes within honeybee colonies, epidemiology and foraging are well understood and described in the models, but there is no model that couples in-hive dynamics and pathology with foraging dynamics in realistic landscapes. Synthesis and applications. We describe how a new integrated model could be built to simulate multifactorial impacts on the honeybee colony system, using building blocks from the reviewed models. The development of such a tool would not only highlight empirical research priorities but also provide an important forecasting tool for policy makers and beekeepers, and we list examples of relevant applications to bee disease and landscape management decisions. PMID:24223431

The bite of the honeybee: 2-heptanone secreted from honeybee mandibles during a bite acts as a local anaesthetic in insects and mammals.

PubMed

Papachristoforou, Alexandros; Kagiava, Alexia; Papaefthimiou, Chrisovalantis; Termentzi, Aikaterini; Fokialakis, Nikolas; Skaltsounis, Alexios-Leandros; Watkins, Max; Arnold, Gérard; Theophilidis, George

2012-01-01

Honeybees secrete 2-heptanone (2-H) from their mandibular glands when they bite. Researchers have identified several possible functions: 2-H could act as an alarm pheromone to recruit guards and soldiers, it could act as a chemical marker, or it could have some other function. The actual role of 2-H in honeybee behaviour remains unresolved. In this study, we show that 2-H acts as an anaesthetic in small arthropods, such as wax moth larva (WML) and Varroa mites, which are paralysed after a honeybee bite. We demonstrated that honeybee mandibles can penetrate the cuticle of WML, introducing less than one nanolitre of 2-H into the WML open circulatory system and causing instantaneous anaesthetization that lasts for a few minutes. The first indication that 2-H acts as a local anaesthetic was that its effect on larval response, inhibition and recovery is very similar to that of lidocaine. We compared the inhibitory effects of 2-H and lidocaine on voltage-gated sodium channels. Although both compounds blocked the hNav1.6 and hNav1.2 channels, lidocaine was slightly more effective, 2.82 times, on hNav.6. In contrast, when the two compounds were tested using an ex vivo preparation-the isolated rat sciatic nerve-the function of the two compounds was so similar that we were able to definitively classify 2-H as a local anaesthetic. Using the same method, we showed that 2-H has the fastest inhibitory effect of all alkyl-ketones tested, including the isomers 3- and 4-heptanone. This suggests that natural selection may have favoured 2-H over other, similar compounds because of the associated fitness advantages it confers. Our results reveal a previously unknown role of 2-H in honeybee defensive behaviour and due to its minor neurotoxicity show potential for developing a new local anaesthetic from a natural product, which could be used in human and veterinary medicine.

Exposure to acetylcholinesterase inhibitors alters the physiology and motor function of honeybees.

PubMed

Williamson, Sally M; Moffat, Christopher; Gomersall, Martha A E; Saranzewa, Nastja; Connolly, Christopher N; Wright, Geraldine A

2013-01-01

Cholinergic signaling is fundamental to neuromuscular function in most organisms. Sub-lethal doses of neurotoxic pesticides that target cholinergic signaling can alter the behavior of insects in subtle ways; their influence on non-target organisms may not be readily apparent in simple mortality studies. Beneficial arthropods such as honeybees perform sophisticated behavioral sequences during foraging that, if influenced by pesticides, could impair foraging success and reduce colony health. Here, we investigate the behavioral effects on honeybees of exposure to a selection of pesticides that target cholinergic signaling by inhibiting acetylcholinesterase (AChE). To examine how continued exposure to AChE inhibitors affected motor function, we fed adult foraging worker honeybees sub-lethal concentrations of these compounds in sucrose solution for 24 h. Using an assay for locomotion in bees, we scored walking, stopped, grooming, and upside down behavior continuously for 15 min. At a 10 nM concentration, all the AChE inhibitors caused similar effects on behavior, notably increased grooming activity and changes in the frequency of bouts of behavior such as head grooming. Coumaphos caused dose-dependent effects on locomotion as well as grooming behavior, and a 1 μM concentration of coumaphos induced symptoms of malaise such as abdomen grooming and defecation. Biochemical assays confirmed that the four compounds we assayed (coumaphos, aldicarb, chlorpyrifos, and donepezil) or their metabolites acted as AChE inhibitors in bees. Furthermore, we show that transcript expression levels of two honeybee AChE inhibitors were selectively upregulated in the brain and in gut tissues in response to AChE inhibitor exposure. The results of our study imply that the effects of pesticides that rely on this mode of action have subtle yet profound effects on physiological effects on behavior that could lead to reduced survival.

Exposure to Acetylcholinesterase Inhibitors Alters the Physiology and Motor Function of Honeybees

PubMed Central

Williamson, Sally M.; Moffat, Christopher; Gomersall, Martha A. E.; Saranzewa, Nastja; Connolly, Christopher N.; Wright, Geraldine A.

2013-01-01

Cholinergic signaling is fundamental to neuromuscular function in most organisms. Sub-lethal doses of neurotoxic pesticides that target cholinergic signaling can alter the behavior of insects in subtle ways; their influence on non-target organisms may not be readily apparent in simple mortality studies. Beneficial arthropods such as honeybees perform sophisticated behavioral sequences during foraging that, if influenced by pesticides, could impair foraging success and reduce colony health. Here, we investigate the behavioral effects on honeybees of exposure to a selection of pesticides that target cholinergic signaling by inhibiting acetylcholinesterase (AChE). To examine how continued exposure to AChE inhibitors affected motor function, we fed adult foraging worker honeybees sub-lethal concentrations of these compounds in sucrose solution for 24 h. Using an assay for locomotion in bees, we scored walking, stopped, grooming, and upside down behavior continuously for 15 min. At a 10 nM concentration, all the AChE inhibitors caused similar effects on behavior, notably increased grooming activity and changes in the frequency of bouts of behavior such as head grooming. Coumaphos caused dose-dependent effects on locomotion as well as grooming behavior, and a 1 μM concentration of coumaphos induced symptoms of malaise such as abdomen grooming and defecation. Biochemical assays confirmed that the four compounds we assayed (coumaphos, aldicarb, chlorpyrifos, and donepezil) or their metabolites acted as AChE inhibitors in bees. Furthermore, we show that transcript expression levels of two honeybee AChE inhibitors were selectively upregulated in the brain and in gut tissues in response to AChE inhibitor exposure. The results of our study imply that the effects of pesticides that rely on this mode of action have subtle yet profound effects on physiological effects on behavior that could lead to reduced survival. PMID:23386834

Agricultural Policies Exacerbate Honeybee Pollination Service Supply-Demand Mismatches Across Europe

PubMed Central

Breeze, Tom D.; Vaissière, Bernard E.; Bommarco, Riccardo; Petanidou, Theodora; Seraphides, Nicos; Kozák, Lajos; Scheper, Jeroen; Biesmeijer, Jacobus C.; Kleijn, David; Gyldenkærne, Steen; Moretti, Marco; Holzschuh, Andrea; Steffan-Dewenter, Ingolf; Stout, Jane C.; Pärtel, Meelis; Zobel, Martin; Potts, Simon G.

2014-01-01

Declines in insect pollinators across Europe have raised concerns about the supply of pollination services to agriculture. Simultaneously, EU agricultural and biofuel policies have encouraged substantial growth in the cultivated area of insect pollinated crops across the continent. Using data from 41 European countries, this study demonstrates that the recommended number of honeybees required to provide crop pollination across Europe has risen 4.9 times as fast as honeybee stocks between 2005 and 2010. Consequently, honeybee stocks were insufficient to supply >90% of demands in 22 countries studied. These findings raise concerns about the capacity of many countries to cope with major losses of wild pollinators and highlight numerous critical gaps in current understanding of pollination service supplies and demands, pointing to a pressing need for further research into this issue. PMID:24421873

Presence of Nosema ceranae associated with honeybee queen introductions.

PubMed

Muñoz, Irene; Cepero, Almudena; Pinto, Maria Alice; Martín-Hernández, Raquel; Higes, Mariano; De la Rúa, Pilar

2014-04-01

Microsporidiosis caused by Nosema species is one of the factors threatening the health of the honeybee (Apis mellifera), which is an essential element in agriculture mainly due to its pollination function. The dispersion of this pathogen may be influenced by many factors, including various aspects of beekeeping management such as introduction of queens with different origin. Herein we study the relation of the presence and distribution of Nosema spp. and the replacement of queens in honeybee populations settled on the Atlantic Canary Islands. While Nosema apis has not been detected, an increase of the presence and distribution of Nosema ceranae during the last decade has been observed in parallel with a higher frequency of foreign queens. On the other hand, a reduction of the number of N. ceranae positive colonies was observed on those islands with continued replacement of queens. We suggest that such replacement could help maintaining low rates of Nosema infection, but healthy queens native to these islands should be used in order to conserve local honeybee diversity. Copyright © 2014 Elsevier B.V. All rights reserved.

Plant microRNAs in larval food regulate honeybee caste development

PubMed Central

Zhou, Zhen; Kong, Yan; Liang, Hongwei; Lin, Zheguang; Luo, Jun; Zheng, Huoqing; Wan, Ping; Zhang, Junfeng; Zen, Ke; Chen, Jiong; Hu, Fuliang; Zhang, Chen-Yu; Ren, Jie

2017-01-01

The major environmental determinants of honeybee caste development come from larval nutrients: royal jelly stimulates the differentiation of larvae into queens, whereas beebread leads to worker bee fate. However, these determinants are not fully characterized. Here we report that plant RNAs, particularly miRNAs, which are more enriched in beebread than in royal jelly, delay development and decrease body and ovary size in honeybees, thereby preventing larval differentiation into queens and inducing development into worker bees. Mechanistic studies reveal that amTOR, a stimulatory gene in caste differentiation, is the direct target of miR162a. Interestingly, the same effect also exists in non-social Drosophila. When such plant RNAs and miRNAs are fed to Drosophila larvae, they cause extended developmental times and reductions in body weight and length, ovary size and fecundity. This study identifies an uncharacterized function of plant miRNAs that fine-tunes honeybee caste development, offering hints for understanding cross-kingdom interaction and co-evolution. PMID:28859085

Plant microRNAs in larval food regulate honeybee caste development.

PubMed

Zhu, Kegan; Liu, Minghui; Fu, Zheng; Zhou, Zhen; Kong, Yan; Liang, Hongwei; Lin, Zheguang; Luo, Jun; Zheng, Huoqing; Wan, Ping; Zhang, Junfeng; Zen, Ke; Chen, Jiong; Hu, Fuliang; Zhang, Chen-Yu; Ren, Jie; Chen, Xi

2017-08-01

The major environmental determinants of honeybee caste development come from larval nutrients: royal jelly stimulates the differentiation of larvae into queens, whereas beebread leads to worker bee fate. However, these determinants are not fully characterized. Here we report that plant RNAs, particularly miRNAs, which are more enriched in beebread than in royal jelly, delay development and decrease body and ovary size in honeybees, thereby preventing larval differentiation into queens and inducing development into worker bees. Mechanistic studies reveal that amTOR, a stimulatory gene in caste differentiation, is the direct target of miR162a. Interestingly, the same effect also exists in non-social Drosophila. When such plant RNAs and miRNAs are fed to Drosophila larvae, they cause extended developmental times and reductions in body weight and length, ovary size and fecundity. This study identifies an uncharacterized function of plant miRNAs that fine-tunes honeybee caste development, offering hints for understanding cross-kingdom interaction and co-evolution.

Evidence of trapline foraging in honeybees.

PubMed

Buatois, Alexis; Lihoreau, Mathieu

2016-08-15

Central-place foragers exploiting floral resources often use multi-destination routes (traplines) to maximise their foraging efficiency. Recent studies on bumblebees have showed how solitary foragers can learn traplines, minimising travel costs between multiple replenishing feeding locations. Here we demonstrate a similar routing strategy in the honeybee (Apis mellifera), a major pollinator known to recruit nestmates to discovered food resources. Individual honeybees trained to collect sucrose solution from four artificial flowers arranged within 10 m of the hive location developed repeatable visitation sequences both in the laboratory and in the field. A 10-fold increase of between-flower distances considerably intensified this routing behaviour, with bees establishing more stable and more efficient routes at larger spatial scales. In these advanced social insects, trapline foraging may complement cooperative foraging for exploiting food resources near the hive (where dance recruitment is not used) or when resources are not large enough to sustain multiple foragers at once. © 2016. Published by The Company of Biologists Ltd.

Modelling the spread of American foulbrood in honeybees

PubMed Central

Datta, Samik; Bull, James C.; Budge, Giles E.; Keeling, Matt J.

2013-01-01

We investigate the spread of American foulbrood (AFB), a disease caused by the bacterium Paenibacillus larvae, that affects bees and can be extremely damaging to beehives. Our dataset comes from an inspection period carried out during an AFB epidemic of honeybee colonies on the island of Jersey during the summer of 2010. The data include the number of hives of honeybees, location and owner of honeybee apiaries across the island. We use a spatial SIR model with an underlying owner network to simulate the epidemic and characterize the epidemic using a Markov chain Monte Carlo (MCMC) scheme to determine model parameters and infection times (including undetected ‘occult’ infections). Likely methods of infection spread can be inferred from the analysis, with both distance- and owner-based transmissions being found to contribute to the spread of AFB. The results of the MCMC are corroborated by simulating the epidemic using a stochastic SIR model, resulting in aggregate levels of infection that are comparable to the data. We use this stochastic SIR model to simulate the impact of different control strategies on controlling the epidemic. It is found that earlier inspections result in smaller epidemics and a higher likelihood of AFB extinction. PMID:24026473

Side-Specific Reward Memories in Honeybees

ERIC Educational Resources Information Center

Gil, Mariana; Menzel, Randolf; De Marco, Rodrigo J.

2009-01-01

We report a hitherto unknown form of side-specific learning in honeybees. We trained bees individually by coupling gustatory and mechanical stimulation of each antenna with either increasing or decreasing volumes of sucrose solution offered to the animal's proboscis along successive learning trials. Next, we examined their proboscis extension…

Flow currents and ventilation in Langstroth beehives due to brood thermoregulation efforts of honeybees.

PubMed

Sudarsan, Rangarajan; Thompson, Cody; Kevan, Peter G; Eberl, Hermann J

2012-02-21

Beekeepers universally agree that ensuring sufficient ventilation is vital for sustaining a thriving, healthy honeybee colony. Despite this fact, surprisingly little is known about the ventilation and flow patterns in bee hives. We take a first step towards developing a model-based approach that uses computational fluid dynamics to simulate natural ventilation flow inside a standard Langstroth beehive. A 3-D model of a Langstroth beehive with one brood chamber and one honey super was constructed and inside it the honeybee colony was distributed among different clusters each occupying the different bee-spaces between frames in the brood chamber. For the purpose of modeling, each honeybee cluster was treated as an air-saturated porous medium with constant porosity. Heat and mass transfer interactions of the honeybees with the air, the outcome of metabolism, were captured in the porous medium model as source and sink terms appearing in the governing equations of fluid dynamics. The temperature of the brood that results from the thermoregulation efforts of the colony is applied as a boundary condition for the governing equations. The governing equations for heat, mass transport and fluid flow were solved using Fluent(©), a commercially available CFD program. The results from the simulations indicate that (a) both heat and mass transfer resulting from honeybee metabolism play a vital role in determining the structure of the flow inside the beehive and mass transfer cannot be neglected, (b) at low ambient temperatures, the nonuniform temperature profile on comb surfaces that results from brood incubation enhances flow through the honeybee cluster which removes much of the carbon-dioxide produced by the cluster resulting in lower carbon-dioxide concentration next to the brood, (c) increasing ambient (outside) air temperature causes ventilation flow rate to drop resulting in weaker flow inside the beehive. Flow visualization indicates that at low ambient air temperatures

Interpatch foraging in honeybees-rational decision making at secondary hubs based upon time and motivation.

PubMed

Najera, Daniel A; McCullough, Erin L; Jander, Rudolf

2012-11-01

For honeybees, Apis mellifera, the hive has been well known to function as a primary decision-making hub, a place from which foragers decide among various directions, distances, and times of day to forage efficiently. Whether foraging honeybees can make similarly complex navigational decisions from locations away from the hive is unknown. To examine whether or not such secondary decision-making hubs exist, we trained bees to forage at four different locations. Specifically, we trained honeybees to first forage to a distal site "CT" 100 m away from the hive; if food was present, they fed and then chose to go home. If food was not present, the honeybees were trained to forage to three auxiliary sites, each at a different time of the day: A in the morning, B at noon, and C in the afternoon. The foragers learned to check site CT for food first and then efficiently depart to the correct location based upon the time of day if there was no food at site CT. Thus, the honeybees were able to cognitively map motivation, time, and five different locations (Hive, CT, A, B, and C) in two spatial dimensions; these are the contents of the cognitive map used by the honeybees here. While at site CT, we verified that the honeybees could choose between 4 different directions (to A, B, C, and the Hive) and thus label it as a secondary decision-making hub. The observed decision making uncovered here is inferred to constitute genuine logical operations, involving a branched structure, based upon the premises of motivational state, and spatiotemporal knowledge.

Perceptual and Neural Olfactory Similarity in Honeybees

PubMed Central

Sandoz, Jean-Christophe

2005-01-01

The question of whether or not neural activity patterns recorded in the olfactory centres of the brain correspond to olfactory perceptual measures remains unanswered. To address this question, we studied olfaction in honeybees Apis mellifera using the olfactory conditioning of the proboscis extension response. We conditioned bees to odours and tested generalisation responses to different odours. Sixteen odours were used, which varied both in their functional group (primary and secondary alcohols, aldehydes and ketones) and in their carbon-chain length (from six to nine carbons).The results obtained by presentation of a total of 16 × 16 odour pairs show that (i) all odorants presented could be learned, although acquisition was lower for short-chain ketones; (ii) generalisation varied depending both on the functional group and the carbon-chain length of odours trained; higher generalisation was found between long-chain than between short-chain molecules and between groups such as primary and secondary alcohols; (iii) for some odour pairs, cross-generalisation between odorants was asymmetric; (iv) a putative olfactory space could be defined for the honeybee with functional group and carbon-chain length as inner dimensions; (v) perceptual distances in such a space correlate well with physiological distances determined from optophysiological recordings of antennal lobe activity. We conclude that functional group and carbon-chain length are inner dimensions of the honeybee olfactory space and that neural activity in the antennal lobe reflects the perceptual quality of odours. PMID:15736975

Parasite-insecticide interactions: a case study of Nosema ceranae and fipronil synergy on honeybee

PubMed Central

Aufauvre, Julie; Biron, David G.; Vidau, Cyril; Fontbonne, Régis; Roudel, Mathieu; Diogon, Marie; Viguès, Bernard; Belzunces, Luc P.; Delbac, Frédéric; Blot, Nicolas

2012-01-01

In ecosystems, a variety of biological, chemical and physical stressors may act in combination to induce illness in populations of living organisms. While recent surveys reported that parasite-insecticide interactions can synergistically and negatively affect honeybee survival, the importance of sequence in exposure to stressors has hardly received any attention. In this work, Western honeybees (Apis mellifera) were sequentially or simultaneously infected by the microsporidian parasite Nosema ceranae and chronically exposed to a sublethal dose of the insecticide fipronil, respectively chosen as biological and chemical stressors. Interestingly, every combination tested led to a synergistic effect on honeybee survival, with the most significant impacts when stressors were applied at the emergence of honeybees. Our study presents significant outcomes on beekeeping management but also points out the potential risks incurred by any living organism frequently exposed to both pathogens and insecticides in their habitat. PMID:22442753

Detection of Illicit Drugs by Trained Honeybees (Apis mellifera).

PubMed

Schott, Matthias; Klein, Birgit; Vilcinskas, Andreas

2015-01-01

Illegal drugs exacerbate global social challenges such as substance addiction, mental health issues and violent crime. Police and customs officials often rely on specially-trained sniffer dogs, which act as sensitive biological detectors to find concealed illegal drugs. However, the dog "alert" is no longer sufficient evidence to allow a search without a warrant or additional probable cause because cannabis has been legalized in two US states and is decriminalized in many others. Retraining dogs to recognize a narrower spectrum of drugs is difficult and training new dogs is time consuming, yet there are no analytical devices with the portability and sensitivity necessary to detect substance-specific chemical signatures. This means there is currently no substitute for sniffer dogs. Here we describe an insect screening procedure showing that the western honeybee (Apis mellifera) can sense volatiles associated with pure samples of heroin and cocaine. We developed a portable electroantennographic device for the on-site measurement of volatile perception by these insects, and found a positive correlation between honeybee antennal responses and the concentration of specific drugs in test samples. Furthermore, we tested the ability of honeybees to learn the scent of heroin and trained them to show a reliable behavioral response in the presence of a highly-diluted scent of pure heroin. Trained honeybees could therefore be used to complement or replace the role of sniffer dogs as part of an automated drug detection system. Insects are highly sensitive to volatile compounds and provide an untapped resource for the development of biosensors. Automated conditioning as presented in this study could be developed as a platform for the practical detection of illicit drugs using insect-based sensors.

Detection of Illicit Drugs by Trained Honeybees (Apis mellifera)

PubMed Central

Schott, Matthias; Klein, Birgit; Vilcinskas, Andreas

2015-01-01

Illegal drugs exacerbate global social challenges such as substance addiction, mental health issues and violent crime. Police and customs officials often rely on specially-trained sniffer dogs, which act as sensitive biological detectors to find concealed illegal drugs. However, the dog “alert” is no longer sufficient evidence to allow a search without a warrant or additional probable cause because cannabis has been legalized in two US states and is decriminalized in many others. Retraining dogs to recognize a narrower spectrum of drugs is difficult and training new dogs is time consuming, yet there are no analytical devices with the portability and sensitivity necessary to detect substance-specific chemical signatures. This means there is currently no substitute for sniffer dogs. Here we describe an insect screening procedure showing that the western honeybee (Apis mellifera) can sense volatiles associated with pure samples of heroin and cocaine. We developed a portable electroantennographic device for the on-site measurement of volatile perception by these insects, and found a positive correlation between honeybee antennal responses and the concentration of specific drugs in test samples. Furthermore, we tested the ability of honeybees to learn the scent of heroin and trained them to show a reliable behavioral response in the presence of a highly-diluted scent of pure heroin. Trained honeybees could therefore be used to complement or replace the role of sniffer dogs as part of an automated drug detection system. Insects are highly sensitive to volatile compounds and provide an untapped resource for the development of biosensors. Automated conditioning as presented in this study could be developed as a platform for the practical detection of illicit drugs using insect-based sensors. PMID:26083377

Small hive beetles survive in honeybee prisons by behavioural mimicry

NASA Astrophysics Data System (ADS)

Ellis, J. D.; Pirk, C. W. W.; Hepburn, H. R.; Kastberger, G.; Elzen, P. J.

2002-05-01

We report the results of a simple experiment to determine whether honeybees feed their small hive beetle nest parasites. Honeybees incarcerate the beetles in cells constructed of plant resins and continually guard them. The longevity of incarcerated beetles greatly exceeds their metabolic reserves. We show that survival of small hive beetles derives from behavioural mimicry by which the beetles induce the bees to feed them trophallactically. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at htpp://dx.doi.org/10.1007/s00114-002-0326-y.

Parasitic Cape honeybee workers, Apis mellifera capensis, evade policing

NASA Astrophysics Data System (ADS)

Martin, Stephen J.; Beekman, Madeleine; Wossler, Theresa C.; Ratnieks, Francis L. W.

2002-01-01

Relocation of the Cape honeybee, Apis mellifera capensis, by bee-keepers from southern to northern South Africa in 1990 has caused widespread death of managed African honeybee, A. m. scutellata, colonies. Apis mellifera capensis worker bees are able to lay diploid, female eggs without mating by means of automictic thelytoky (meiosis followed by fusion of two meiotic products to restore egg diploidy), whereas workers of other honeybee subspecies are able to lay only haploid, male eggs. The A. m. capensis workers, which are parasitizing and killing A. m. scutellata colonies in northern South Africa, are the asexual offspring of a single, original worker in which the small amount of genetic variation observed is due to crossing over during meiosis (P. Kryger, personal communication). Here we elucidate two principal mechanisms underlying this parasitism. Parasitic A. m. capensis workers activate their ovaries in host colonies that have a queen present (queenright colonies), and they lay eggs that evade being killed by other workers (worker policing)-the normal fate of worker-laid eggs in colonies with a queen. This unique parasitism by workers is an instance in which a society is unable to control the selfish actions of its members.

Ethanol increases HSP70 concentrations in honeybee (Apis mellifera L.) brain tissue.

PubMed

Hranitz, John M; Abramson, Charles I; Carter, Richard P

2010-05-01

Previous research on the honeybee ethanol model established how acute ethanol exposure altered function at different levels of organization: behavior and learning, ecology, and physiology. The purpose of this study was to evaluate whether ethanol doses that affect honeybee behavior also induce a significant stress response, measured by heat shock protein 70 (HSP70) concentrations, in honeybee brain tissues. Experiment 1 examined how pretreatment handling influenced brain HSP70 concentrations in three pretreatment groups of bees; immediately after being collected, after being harnessed and fed, and after 22-24h in a harness. HSP70 concentrations did not differ among pretreatment groups within replicates, although we observed significantly different HSP70 concentrations between the two replicates. Experiment 2 investigated the relationship between ethanol dose and brain HSP70 concentrations. Bees were placed in seven experimental groups, the three pretreatment groups as in Experiment 1 and four ethanol-fed groups. Bees in ethanol treatments were fed 1.5M sucrose (control) and 1.5M sucrose-ethanol solutions containing 2.5, 5, and 10% ethanol, allowed to sit for 4h, and dissected brains were assayed for HSP70. We observed ethanol-induced increases in honeybee brain HSP70 concentrations from the control group through the 5% ethanol group. Only bees in the 5% ethanol group had HSP70 concentrations significantly higher than the control group. The inverted U-shaped ethanol dose-HSP70 concentration response curve indicated that ingestion of 2.5% ethanol and 5% ethanol stimulated the stress response, whereas ingestion of 10% ethanol inhibited the stress response. Doses that show maximum HSP70 concentration (5% ethanol) or HSP70 inhibition (10% ethanol) correspond to those (> or =5% ethanol) that also impaired honeybees in previous studies. We conclude that acute ethanol intoxication by solutions containing > or =5% ethanol causes significant ethanol-induced stress in brain

Age structure is critical to the population dynamics and survival of honeybee colonies

PubMed Central

Betti, M. I.; Wahl, L. M.

2016-01-01

Age structure is an important feature of the division of labour within honeybee colonies, but its effects on colony dynamics have rarely been explored. We present a model of a honeybee colony that incorporates this key feature, and use this model to explore the effects of both winter and disease on the fate of the colony. The model offers a novel explanation for the frequently observed phenomenon of ‘spring dwindle’, which emerges as a natural consequence of the age-structured dynamics. Furthermore, the results indicate that a model taking age structure into account markedly affects the predicted timing and severity of disease within a bee colony. The timing of the onset of disease with respect to the changing seasons may also have a substantial impact on the fate of a honeybee colony. Finally, simulations predict that an infection may persist in a honeybee colony over several years, with effects that compound over time. Thus, the ultimate collapse of the colony may be the result of events several years past. PMID:28018627

Age structure is critical to the population dynamics and survival of honeybee colonies.

PubMed

Betti, M I; Wahl, L M; Zamir, M

2016-11-01

Age structure is an important feature of the division of labour within honeybee colonies, but its effects on colony dynamics have rarely been explored. We present a model of a honeybee colony that incorporates this key feature, and use this model to explore the effects of both winter and disease on the fate of the colony. The model offers a novel explanation for the frequently observed phenomenon of 'spring dwindle', which emerges as a natural consequence of the age-structured dynamics. Furthermore, the results indicate that a model taking age structure into account markedly affects the predicted timing and severity of disease within a bee colony. The timing of the onset of disease with respect to the changing seasons may also have a substantial impact on the fate of a honeybee colony. Finally, simulations predict that an infection may persist in a honeybee colony over several years, with effects that compound over time. Thus, the ultimate collapse of the colony may be the result of events several years past.

MALDI Imaging Analysis of Neuropeptides in Africanized Honeybee (Apis mellifera) Brain: Effect of Aggressiveness.

PubMed

Pratavieira, Marcel; Menegasso, Anally Ribeiro da Silva; Esteves, Franciele Grego; Sato, Kenny Umino; Malaspina, Osmar; Palma, Mario Sérgio

2018-05-18

The aggressiveness in honeybees seems to be regulated by multiple genes, under the influence of different factors, such as polyethism of workers, environmental factors, and response to alarm pheromones, creating a series of behavioral responses. It is suspected that neuropeptides seem to be involved with the regulation of the aggressive behavior. The role of allatostatin and tachykinin-related neuropeptides in honeybee brain during the aggressive behavior is unknown; thus, worker honeybees were stimulated to attack and to sting leather targets hanged in front of the colonies. The aggressive individuals were collected and immediately frozen in liquid nitrogen; the heads were removed, and sliced at sagittal plan. The brain slices were submitted to MALDI-Spectral-Imaging analysis, and the results of the present study reported the processing of the precursors proteins into mature forms of the neuropeptides AmAST A (59-76) (AYTYVSEYKRLPVYNFGL-NH2), AmAST A (69-76) (LPVYNFGL-NH2), AmTRP (88 - 96) (APMGFQGMR-NH2), and AmTRP (254 - 262) (ARMGFHGMR-NH2), which apparently acted in different neuropils of honeybee brain, during the aggressive behavior, possibly playing the neuromodulation of different aspects of this complex behavior. These results were biologically validated performing aggressiveness-related behavioral assays, using young honeybee workers that received 1 ng of AmAST A (69-76) or AmTRP (88 - 96) via hemocele. The young workers that were not expected to be aggressive individuals, presented a complete series of the aggressive behaviors, in presence of the neuropeptides, corroborating the hypothesis that correlates the presence of mature AmASTs A and AmTRPs in honeybee brain with the aggressiveness of this insect.

Interneurons in the Honeybee Primary Auditory Center Responding to Waggle Dance-Like Vibration Pulses.

PubMed

Ai, Hiroyuki; Kai, Kazuki; Kumaraswamy, Ajayrama; Ikeno, Hidetoshi; Wachtler, Thomas

2017-11-01

Female honeybees use the "waggle dance" to communicate the location of nectar sources to their hive mates. Distance information is encoded in the duration of the waggle phase (von Frisch, 1967). During the waggle phase, the dancer produces trains of vibration pulses, which are detected by the follower bees via Johnston's organ located on the antennae. To uncover the neural mechanisms underlying the encoding of distance information in the waggle dance follower, we investigated morphology, physiology, and immunohistochemistry of interneurons arborizing in the primary auditory center of the honeybee ( Apis mellifera ). We identified major interneuron types, named DL-Int-1, DL-Int-2, and bilateral DL-dSEG-LP, that responded with different spiking patterns to vibration pulses applied to the antennae. Experimental and computational analyses suggest that inhibitory connection plays a role in encoding and processing the duration of vibration pulse trains in the primary auditory center of the honeybee. SIGNIFICANCE STATEMENT The waggle dance represents a form of symbolic communication used by honeybees to convey the location of food sources via species-specific sound. The brain mechanisms used to decipher this symbolic information are unknown. We examined interneurons in the honeybee primary auditory center and identified different neuron types with specific properties. The results of our computational analyses suggest that inhibitory connection plays a role in encoding waggle dance signals. Our results are critical for understanding how the honeybee deciphers information from the sound produced by the waggle dance and provide new insights regarding how common neural mechanisms are used by different species to achieve communication. Copyright © 2017 the authors 0270-6474/17/3710624-12$15.00/0.

Honeybee foraging in differentially structured landscapes.

PubMed

Steffan-Dewenter, Ingolf; Kuhn, Arno

2003-03-22

Honeybees communicate the distance and location of resource patches by bee dances, but this spatial information has rarely been used to study their foraging ecology. We analysed, for the first time to the best of the authors' knowledge, foraging distances and dance activities of honeybees in relation to landscape structure, season and colony using a replicated experimental approach on a landscape scale. We compared three structurally simple landscapes characterized by a high proportion of arable land and large patches, with three complex landscapes with a high proportion of semi-natural perennial habitats and low mean patch size. Four observation hives were placed in the centre of the landscapes and switched at regular intervals between the six landscapes from the beginning of May to the end of July. A total of 1137 bee dances were observed and decoded. Overall mean foraging distance was 1526.1 +/- 37.2 m, the median 1181.5 m and range 62.1-10037.1 m. Mean foraging distances of all bees and foraging distances of nectar-collecting bees did not significantly differ between simple and complex landscapes, but varied between month and colonies. Foraging distances of pollen-collecting bees were significantly larger in simple (1743 +/- 95.6 m) than in complex landscapes (1543.4 +/- 71 m) and highest in June when resources were scarce. Dancing activity, i.e. the number of observed bee dances per unit time, was significantly higher in complex than in simple landscapes, presumably because of larger spatial and temporal variability of resource patches in complex landscapes. The results facilitate an understanding of how human landscape modification may change the evolutionary significance of bee dances and ecological interactions, such as pollination and competition between honeybees and other bee species.

Mast Cells Can Enhance Resistance to Snake and Honeybee Venoms

NASA Astrophysics Data System (ADS)

Metz, Martin; Piliponsky, Adrian M.; Chen, Ching-Cheng; Lammel, Verena; Åbrink, Magnus; Pejler, Gunnar; Tsai, Mindy; Galli, Stephen J.

2006-07-01

Snake or honeybee envenomation can cause substantial morbidity and mortality, and it has been proposed that the activation of mast cells by snake or insect venoms can contribute to these effects. We show, in contrast, that mast cells can significantly reduce snake-venom-induced pathology in mice, at least in part by releasing carboxypeptidase A and possibly other proteases, which can degrade venom components. Mast cells also significantly reduced the morbidity and mortality induced by honeybee venom. These findings identify a new biological function for mast cells in enhancing resistance to the morbidity and mortality induced by animal venoms.

Short-sighted evolution of virulence in parasitic honeybee workers ( Apis mellifera capensis Esch.)

NASA Astrophysics Data System (ADS)

Moritz, Robin F. A.; Pirk, Christian W. W.; Hepburn, H. Randall; Neumann, Peter

2008-06-01

The short-sighted selection hypothesis for parasite virulence predicts that winners of within-host competition are poorer at transmission to new hosts. Social parasitism by self-replicating, female-producing workers occurs in the Cape honeybee Apis mellifera capensis, and colonies of other honeybee subspecies are susceptible hosts. We found high within-host virulence but low transmission rates in a clone of social parasitic A. m. capensis workers invading the neighbouring subspecies A. m. scutellata. In contrast, parasitic workers from the endemic range of A. m. capensis showed low within-host virulence but high transmission rates. This suggests a short-sighted selection scenario for the host-parasite co-evolution in the invasive range of the Cape honeybee, probably facilitated by beekeeping-assisted parasite transmission in apiaries.

Therapeutic Properties of Bioactive Compounds from Different Honeybee Products

PubMed Central

Cornara, Laura; Biagi, Marco; Xiao, Jianbo; Burlando, Bruno

2017-01-01

Honeybees produce honey, royal jelly, propolis, bee venom, bee pollen, and beeswax, which potentially benefit to humans due to the bioactives in them. Clinical standardization of these products is hindered by chemical variability depending on honeybee and botanical sources, but different molecules have been isolated and pharmacologically characterized. Major honey bioactives include phenolics, methylglyoxal, royal jelly proteins (MRJPs), and oligosaccharides. In royal jelly there are antimicrobial jelleins and royalisin peptides, MRJPs, and hydroxy-decenoic acid derivatives, notably 10-hydroxy-2-decenoic acid (10-HDA), with antimicrobial, anti-inflammatory, immunomodulatory, neuromodulatory, metabolic syndrome preventing, and anti-aging activities. Propolis contains caffeic acid phenethyl ester and artepillin C, specific of Brazilian propolis, with antiviral, immunomodulatory, anti-inflammatory and anticancer effects. Bee venom consists of toxic peptides like pain-inducing melittin, SK channel blocking apamin, and allergenic phospholipase A2. Bee pollen is vitaminic, contains antioxidant and anti-inflammatory plant phenolics, as well as antiatherosclerotic, antidiabetic, and hypoglycemic flavonoids, unsaturated fatty acids, and sterols. Beeswax is widely used in cosmetics and makeup. Given the importance of drug discovery from natural sources, this review is aimed at providing an exhaustive screening of the bioactive compounds detected in honeybee products and of their curative or adverse biological effects. PMID:28701955

Optic flow informs distance but not profitability for honeybees.

PubMed

Shafir, Sharoni; Barron, Andrew B

2010-04-22

How do flying insects monitor foraging efficiency? Honeybees (Apis mellifera) use optic flow information as an odometer to estimate distance travelled, but here we tested whether optic flow informs estimation of foraging costs also. Bees were trained to feeders in flight tunnels such that bees experienced the greatest optic flow en route to the feeder closest to the hive. Analyses of dance communication showed that, as expected, bees indicated the close feeder as being further, but they also indicated this feeder as the more profitable, and preferentially visited this feeder when given a choice. We show that honeybee estimates of foraging cost are not reliant on optic flow information. Rather, bees can assess distance and profitability independently and signal these aspects as separate elements of their dances. The optic flow signal is sensitive to the nature of the environment travelled by the bee, and is therefore not a good index of flight energetic costs, but it provides a good indication of distance travelled for purpose of navigation and communication, as long as the dancer and recruit travel similar routes. This study suggests an adaptive dual processing system in honeybees for communicating and navigating distance flown and for evaluating its energetic costs.

Optic flow informs distance but not profitability for honeybees

PubMed Central

Shafir, Sharoni; Barron, Andrew B.

2010-01-01

How do flying insects monitor foraging efficiency? Honeybees (Apis mellifera) use optic flow information as an odometer to estimate distance travelled, but here we tested whether optic flow informs estimation of foraging costs also. Bees were trained to feeders in flight tunnels such that bees experienced the greatest optic flow en route to the feeder closest to the hive. Analyses of dance communication showed that, as expected, bees indicated the close feeder as being further, but they also indicated this feeder as the more profitable, and preferentially visited this feeder when given a choice. We show that honeybee estimates of foraging cost are not reliant on optic flow information. Rather, bees can assess distance and profitability independently and signal these aspects as separate elements of their dances. The optic flow signal is sensitive to the nature of the environment travelled by the bee, and is therefore not a good index of flight energetic costs, but it provides a good indication of distance travelled for purpose of navigation and communication, as long as the dancer and recruit travel similar routes. This study suggests an adaptive dual processing system in honeybees for communicating and navigating distance flown and for evaluating its energetic costs. PMID:20018787

Africanization in the United States: replacement of feral European honeybees (Apis mellifera L.) by an African hybrid swarm.

PubMed

Pinto, M Alice; Rubink, William L; Patton, John C; Coulson, Robert N; Johnston, J Spencer

2005-08-01

The expansion of Africanized honeybees from South America to the southwestern United States in <50 years is considered one of the most spectacular biological invasions yet documented. In the American tropics, it has been shown that during their expansion Africanized honeybees have low levels of introgressed alleles from resident European populations. In the United States, it has been speculated, but not shown, that Africanized honeybees would hybridize extensively with European honeybees. Here we report a continuous 11-year study investigating temporal changes in the genetic structure of a feral population from the southern United States undergoing Africanization. Our microsatellite data showed that (1) the process of Africanization involved both maternal and paternal bidirectional gene flow between European and Africanized honeybees and (2) the panmitic European population was replaced by panmitic mixtures of A. m. scutellata and European genes within 5 years after Africanization. The post-Africanization gene pool (1998-2001) was composed of a diverse array of recombinant classes with a substantial European genetic contribution (mean 25-37%). Therefore, the resulting feral honeybee population of south Texas was best viewed as a hybrid swarm.

Antibiotic exposure perturbs the gut microbiota and elevates mortality in honeybees

PubMed Central

Shaffer, Zack; Moran, Nancy A.

2017-01-01

Gut microbiomes play crucial roles in animal health, and shifts in the gut microbial community structure can have detrimental impacts on hosts. Studies with vertebrate models and human subjects suggest that antibiotic treatments greatly perturb the native gut community, thereby facilitating proliferation of pathogens. In fact, persistent infections following antibiotic treatment are a major medical issue. In apiculture, antibiotics are frequently used to prevent bacterial infections of larval bees, but the impact of antibiotic-induced dysbiosis (microbial imbalance) on bee health and susceptibility to disease has not been fully elucidated. Here, we evaluated the effects of antibiotic exposure on the size and composition of honeybee gut communities. We monitored the survivorship of bees following antibiotic treatment in order to determine if dysbiosis of the gut microbiome impacts honeybee health, and we performed experiments to determine whether antibiotic exposure increases susceptibility to infection by opportunistic pathogens. Our results show that antibiotic treatment can have persistent effects on both the size and composition of the honeybee gut microbiome. Antibiotic exposure resulted in decreased survivorship, both in the hive and in laboratory experiments in which bees were exposed to opportunistic bacterial pathogens. Together, these results suggest that dysbiosis resulting from antibiotic exposure affects bee health, in part due to increased susceptibility to ubiquitous opportunistic pathogens. Not only do our results highlight the importance of the gut microbiome in honeybee health, but they also provide insights into how antibiotic treatment affects microbial communities and host health. PMID:28291793

Queen promiscuity lowers disease within honeybee colonies

PubMed Central

Seeley, Thomas D; Tarpy, David R

2006-01-01

Most species of social insects have singly mated queens, but in some species each queen mates with numerous males to create a colony with a genetically diverse worker force. The adaptive significance of polyandry by social insect queens remains an evolutionary puzzle. Using the honeybee (Apis mellifera), we tested the hypothesis that polyandry improves a colony's resistance to disease. We established colonies headed by queens that had been artificially inseminated by either one or 10 drones. Later, we inoculated these colonies with spores of Paenibacillus larvae, the bacterium that causes a highly virulent disease of honeybee larvae (American foulbrood). We found that, on average, colonies headed by multiple-drone inseminated queens had markedly lower disease intensity and higher colony strength at the end of the summer relative to colonies headed by single-drone inseminated queens. These findings support the hypothesis that polyandry by social insect queens is an adaptation to counter disease within their colonies. PMID:17015336

Function and distribution of 5-HT2 receptors in the honeybee (Apis mellifera).

PubMed

Thamm, Markus; Rolke, Daniel; Jordan, Nadine; Balfanz, Sabine; Schiffer, Christian; Baumann, Arnd; Blenau, Wolfgang

2013-01-01

Serotonin plays a pivotal role in regulating and modulating physiological and behavioral processes in both vertebrates and invertebrates. In the honeybee (Apis mellifera), serotonin has been implicated in division of labor, visual processing, and learning processes. Here, we present the cloning, heterologous expression, and detailed functional and pharmacological characterization of two honeybee 5-HT2 receptors. Honeybee 5-HT2 receptor cDNAs were amplified from brain cDNA. Recombinant cell lines were established constitutively expressing receptor variants. Pharmacological properties of the receptors were investigated by Ca(2+) imaging experiments. Quantitative PCR was applied to explore the expression patterns of receptor mRNAs. The honeybee 5-HT2 receptor class consists of two subtypes, Am5-HT2α and Am5-HT2β. Each receptor gene also gives rise to alternatively spliced mRNAs that possibly code for truncated receptors. Only activation of the full-length receptors with serotonin caused an increase in the intracellular Ca(2+) concentration. The effect was mimicked by the agonists 5-methoxytryptamine and 8-OH-DPAT at low micromolar concentrations. Receptor activities were blocked by established 5-HT receptor antagonists such as clozapine, methiothepin, or mianserin. High transcript numbers were detected in exocrine glands suggesting that 5-HT2 receptors participate in secretory processes in the honeybee. This study marks the first molecular and pharmacological characterization of two 5-HT2 receptor subtypes in the same insect species. The results presented should facilitate further attempts to unravel central and peripheral effects of serotonin mediated by these receptors.

Molecular, pharmacological, and signaling properties of octopamine receptors from honeybee (Apis mellifera) brain.

PubMed

Balfanz, Sabine; Jordan, Nadine; Langenstück, Teresa; Breuer, Johanna; Bergmeier, Vera; Baumann, Arnd

2014-04-01

G protein-coupled receptors are important regulators of cellular signaling processes. Within the large family of rhodopsin-like receptors, those binding to biogenic amines form a discrete subgroup. Activation of biogenic amine receptors leads to transient changes of intracellular Ca²⁺-([Ca²⁺](i)) or 3',5'-cyclic adenosine monophosphate ([cAMP](i)) concentrations. Both second messengers modulate cellular signaling processes and thereby contribute to long-lasting behavioral effects in an organism. In vivo pharmacology has helped to reveal the functional effects of different biogenic amines in honeybees. The phenolamine octopamine is an important modulator of behavior. Binding of octopamine to its receptors causes elevation of [Ca²⁺](i) or [cAMP](i). To date, only one honeybee octopamine receptor that induces Ca²⁺ signals has been molecularly and pharmacologically characterized. Here, we examined the pharmacological properties of four additional honeybee octopamine receptors. When heterologously expressed, all receptors induced cAMP production after binding to octopamine with EC₅₀(s) in the nanomolar range. Receptor activity was most efficiently blocked by mianserin, a substance with antidepressant activity in vertebrates. The rank order of inhibitory potency for potential receptor antagonists was very similar on all four honeybee receptors with mianserin > cyproheptadine > metoclopramide > chlorpromazine > phentolamine. The subroot of octopamine receptors activating adenylyl cyclases is the largest that has so far been characterized in arthropods, and it should now be possible to unravel the contribution of individual receptors to the physiology and behavior of honeybees. © 2013 International Society for Neurochemistry.

Function and Distribution of 5-HT2 Receptors in the Honeybee (Apis mellifera)

PubMed Central

Thamm, Markus; Rolke, Daniel; Jordan, Nadine; Balfanz, Sabine; Schiffer, Christian; Baumann, Arnd; Blenau, Wolfgang

2013-01-01

Background Serotonin plays a pivotal role in regulating and modulating physiological and behavioral processes in both vertebrates and invertebrates. In the honeybee (Apis mellifera), serotonin has been implicated in division of labor, visual processing, and learning processes. Here, we present the cloning, heterologous expression, and detailed functional and pharmacological characterization of two honeybee 5-HT2 receptors. Methods Honeybee 5-HT2 receptor cDNAs were amplified from brain cDNA. Recombinant cell lines were established constitutively expressing receptor variants. Pharmacological properties of the receptors were investigated by Ca2+ imaging experiments. Quantitative PCR was applied to explore the expression patterns of receptor mRNAs. Results The honeybee 5-HT2 receptor class consists of two subtypes, Am5-HT2α and Am5-HT2β. Each receptor gene also gives rise to alternatively spliced mRNAs that possibly code for truncated receptors. Only activation of the full-length receptors with serotonin caused an increase in the intracellular Ca2+ concentration. The effect was mimicked by the agonists 5-methoxytryptamine and 8-OH-DPAT at low micromolar concentrations. Receptor activities were blocked by established 5-HT receptor antagonists such as clozapine, methiothepin, or mianserin. High transcript numbers were detected in exocrine glands suggesting that 5-HT2 receptors participate in secretory processes in the honeybee. Conclusions This study marks the first molecular and pharmacological characterization of two 5-HT2 receptor subtypes in the same insect species. The results presented should facilitate further attempts to unravel central and peripheral effects of serotonin mediated by these receptors. PMID:24324783

Resistance rather than tolerance explains survival of savannah honeybees (Apis mellifera scutellata) to infestation by the parasitic mite Varroa destructor.

PubMed

Strauss, Ursula; Dietemann, Vincent; Human, Hannelie; Crewe, Robin M; Pirk, Christian W W

2016-03-01

Varroa destructor is considered the most damaging parasite affecting honeybees (Apis mellifera L.). However, some honeybee populations such as the savannah honeybee (Apis mellifera scutellata) can survive mite infestation without treatment. It is unclear if survival is due to resistance mechanisms decreasing parasite reproduction or to tolerance mechanisms decreasing the detrimental effects of mites on the host. This study investigates both aspects by quantifying the reproductive output of V. destructor and its physiological costs at the individual host level. Costs measured were not consistently lower when compared with susceptible honeybee populations, indicating a lack of tolerance. In contrast, reproduction of V. destructor mites was distinctly lower than in susceptible populations. There was higher proportion of infertile individuals and the reproductive success of fertile mites was lower than measured to date, even in surviving populations. Our results suggest that survival of savannah honeybees is based on resistance rather than tolerance to this parasite. We identified traits that may be useful for breeding programmes aimed at increasing the survival of susceptible populations. African honeybees may have benefited from a lack of human interference, allowing natural selection to shape a population of honeybees that is more resistant to Varroa mite infestation.

Alfalfa (Medicago sativa L.) seed yield in relation to phosphorus fertilization and honeybee pollination.

PubMed

Al-Kahtani, Saad Naser; Taha, El-Kazafy Abdou; Al-Abdulsalam, Mohammed

2017-07-01

This investigation was conducted at the Agricultural and Veterinary Training and Research Station, King Faisal University, Al-Ahsa, Saudi Arabia, during the alfalfa growing season in 2014. The study aimed to evaluate the impact of phosphorus fertilization and honeybee pollination on alfalfa seed production. The experiment was divided into 9 treatments of open pollination, honeybee pollination, and non-pollination with three different levels (0, 300 or 600 kg P 2 O 5 /ha/year) of triple super phosphate. All vegetative growth attributes of Hassawi alfalfa were significantly higher in the non-insect pollination plots, while the yield and yield component traits were significantly higher with either open pollination or honeybee pollination in parallel with the increasing level of phosphorus fertilizer up to 600 kg P 2 O 5 /ha/year in light salt-affected loamy sand soils. There was no seed yield in Hassawi alfalfa without insect pollination. Therefore, placing honeybee colonies near the fields of Hassawi alfalfa and adding 600 kg P 2 O 5 /ha/year can increase seed production.

Temporal pattern of africanization in a feral honeybee population from Texas inferred from mitochondrial DNA.

PubMed

Pinto, M Alice; Rubink, William L; Coulson, Robert N; Patton, John C; Johnston, J Spencer

2004-05-01

The invasion of Africanized honeybees (Apis mellifera L.) in the Americas provides a window of opportunity to study the dynamics of secondary contact of subspecies of bees that evolved in allopatry in ecologically distinctive habitats of the Old World. We report here the results of an 11-year mitochondrial DNA survey of a feral honeybee population from southern United States (Texas). The mitochondrial haplotype (mitotype) frequencies changed radically during the 11-year study period. Prior to immigration of Africanized honeybees, the resident population was essentially of eastern and western European maternal ancestry. Three years after detection of the first Africanized swarm there was a mitotype turnover in the population from predominantly eastern European to predominantly A. m. scutellata (ancestor of Africanized honeybees). This remarkable change in the mitotype composition coincided with arrival of the parasitic mite Varroa destructor, which was likely responsible for severe losses experienced by colonies of European ancestry. From 1997 onward the population stabilized with most colonies of A. m. scutellata maternal origin.

Honeybee colony disorder in crop areas: the role of pesticides and viruses.

PubMed

Simon-Delso, Noa; San Martin, Gilles; Bruneau, Etienne; Minsart, Laure-Anne; Mouret, Coralie; Hautier, Louis

2014-01-01

As in many other locations in the world, honeybee colony losses and disorders have increased in Belgium. Some of the symptoms observed rest unspecific and their causes remain unknown. The present study aims to determine the role of both pesticide exposure and virus load on the appraisal of unexplained honeybee colony disorders in field conditions. From July 2011 to May 2012, 330 colonies were monitored. Honeybees, wax, beebread and honey samples were collected. Morbidity and mortality information provided by beekeepers, colony clinical visits and availability of analytical matrix were used to form 2 groups: healthy colonies and colonies with disorders (n = 29, n = 25, respectively). Disorders included: (1) dead colonies or colonies in which part of the colony appeared dead, or had disappeared; (2) weak colonies; (3) queen loss; (4) problems linked to brood and not related to any known disease. Five common viruses and 99 pesticides (41 fungicides, 39 insecticides and synergist, 14 herbicides, 5 acaricides and metabolites) were quantified in the samples.The main symptoms observed in the group with disorders are linked to brood and queens. The viruses most frequently found are Black Queen Cell Virus, Sac Brood Virus, Deformed Wing Virus. No significant difference in virus load was observed between the two groups. Three acaricides, 5 insecticides and 13 fungicides were detected in the analysed samples. A significant correlation was found between the presence of fungicide residues and honeybee colony disorders. A significant positive link could also be established between the observation of disorder and the abundance of crop surface around the beehive. According to our results, the role of fungicides as a potential stressor for honeybee colonies should be further studied, either by their direct and/or indirect impacts on bees and bee colonies.

Honeybee Colony Disorder in Crop Areas: The Role of Pesticides and Viruses

PubMed Central

Simon-Delso, Noa; San Martin, Gilles; Bruneau, Etienne; Minsart, Laure-Anne; Mouret, Coralie; Hautier, Louis

2014-01-01

As in many other locations in the world, honeybee colony losses and disorders have increased in Belgium. Some of the symptoms observed rest unspecific and their causes remain unknown. The present study aims to determine the role of both pesticide exposure and virus load on the appraisal of unexplained honeybee colony disorders in field conditions. From July 2011 to May 2012, 330 colonies were monitored. Honeybees, wax, beebread and honey samples were collected. Morbidity and mortality information provided by beekeepers, colony clinical visits and availability of analytical matrix were used to form 2 groups: healthy colonies and colonies with disorders (n = 29, n = 25, respectively). Disorders included: (1) dead colonies or colonies in which part of the colony appeared dead, or had disappeared; (2) weak colonies; (3) queen loss; (4) problems linked to brood and not related to any known disease. Five common viruses and 99 pesticides (41 fungicides, 39 insecticides and synergist, 14 herbicides, 5 acaricides and metabolites) were quantified in the samples.The main symptoms observed in the group with disorders are linked to brood and queens. The viruses most frequently found are Black Queen Cell Virus, Sac Brood Virus, Deformed Wing Virus. No significant difference in virus load was observed between the two groups. Three acaricides, 5 insecticides and 13 fungicides were detected in the analysed samples. A significant correlation was found between the presence of fungicide residues and honeybee colony disorders. A significant positive link could also be established between the observation of disorder and the abundance of crop surface around the beehive. According to our results, the role of fungicides as a potential stressor for honeybee colonies should be further studied, either by their direct and/or indirect impacts on bees and bee colonies. PMID:25048715

Honeybees Learn Odour Mixtures via a Selection of Key Odorants

PubMed Central

Reinhard, Judith; Sinclair, Michael; Srinivasan, Mandyam V.; Claudianos, Charles

2010-01-01

Background The honeybee has to detect, process and learn numerous complex odours from her natural environment on a daily basis. Most of these odours are floral scents, which are mixtures of dozens of different odorants. To date, it is still unclear how the bee brain unravels the complex information contained in scent mixtures. Methodology/Principal Findings This study investigates learning of complex odour mixtures in honeybees using a simple olfactory conditioning procedure, the Proboscis-Extension-Reflex (PER) paradigm. Restrained honeybees were trained to three scent mixtures composed of 14 floral odorants each, and then tested with the individual odorants of each mixture. Bees did not respond to all odorants of a mixture equally: They responded well to a selection of key odorants, which were unique for each of the three scent mixtures. Bees showed less or very little response to the other odorants of the mixtures. The bees' response to mixtures composed of only the key odorants was as good as to the original mixtures of 14 odorants. A mixture composed of the other, non-key-odorants elicited a significantly lower response. Neither an odorant's volatility or molecular structure, nor learning efficiencies for individual odorants affected whether an odorant became a key odorant for a particular mixture. Odorant concentration had a positive effect, with odorants at high concentration likely to become key odorants. Conclusions/Significance Our study suggests that the brain processes complex scent mixtures by predominantly learning information from selected key odorants. Our observations on key odorant learning lend significant support to previous work on olfactory learning and mixture processing in honeybees. PMID:20161714

Worker honeybee sterility: a proteomic analysis of suppressed ovary activation.

PubMed

Cardoen, Dries; Ernst, Ulrich R; Boerjan, Bart; Bogaerts, Annelies; Formesyn, Ellen; de Graaf, Dirk C; Wenseleers, Tom; Schoofs, Liliane; Verleyen, Peter

2012-05-04

Eusocial behavior is extensively studied in the honeybee, Apis mellifera, as it displays an extreme form of altruism. Honeybee workers are generally obligatory sterile in a bee colony headed by a queen, but the inhibition of ovary activation is lifted upon the absence of queen and larvae. Worker bees are then able to develop mature, viable eggs. The detailed repressive physiological mechanisms that are responsible for this remarkable phenomenon are as of yet largely unknown. Physiological studies today mainly focus on the transcriptome, while the proteome stays rather unexplored. Here, we present a quantitative 2-dimensional differential gel electrophoresis comparison between activated and inactivated worker ovaries and brains of reproductive and sterile worker bees, including a spot map of ovaries, containing 197 identified spots. Our findings suggest that suppression of ovary activation might involve a constant interplay between primordial oogenesis and subsequent degradation, which is probably mediated through steroid and neuropeptide hormone signaling. Additionally, the observation of higher viral protein loads in both the brains and ovaries of sterile workers is particularly noteworthy. This data set will be of great value for future research unraveling the physiological mechanisms underlying the altruistic sterility in honeybee workers.

Mechanisms, functions and ecology of colour vision in the honeybee.

PubMed

Hempel de Ibarra, N; Vorobyev, M; Menzel, R

2014-06-01

Research in the honeybee has laid the foundations for our understanding of insect colour vision. The trichromatic colour vision of honeybees shares fundamental properties with primate and human colour perception, such as colour constancy, colour opponency, segregation of colour and brightness coding. Laborious efforts to reconstruct the colour vision pathway in the honeybee have provided detailed descriptions of neural connectivity and the properties of photoreceptors and interneurons in the optic lobes of the bee brain. The modelling of colour perception advanced with the establishment of colour discrimination models that were based on experimental data, the Colour-Opponent Coding and Receptor Noise-Limited models, which are important tools for the quantitative assessment of bee colour vision and colour-guided behaviours. Major insights into the visual ecology of bees have been gained combining behavioural experiments and quantitative modelling, and asking how bee vision has influenced the evolution of flower colours and patterns. Recently research has focussed on the discrimination and categorisation of coloured patterns, colourful scenes and various other groupings of coloured stimuli, highlighting the bees' behavioural flexibility. The identification of perceptual mechanisms remains of fundamental importance for the interpretation of their learning strategies and performance in diverse experimental tasks.

Characterization of the honeybee AmNaV1 channel and tools to assess the toxicity of insecticides.

PubMed

Gosselin-Badaroudine, Pascal; Moreau, Adrien; Delemotte, Lucie; Cens, Thierry; Collet, Claude; Rousset, Matthieu; Charnet, Pierre; Klein, Michael L; Chahine, Mohamed

2015-07-23

Pollination is important for both agriculture and biodiversity. For a significant number of plants, this process is highly, and sometimes exclusively, dependent on the pollination activity of honeybees. The large numbers of honeybee colony losses reported in recent years have been attributed to colony collapse disorder. Various hypotheses, including pesticide overuse, have been suggested to explain the disorder. Using the Xenopus oocytes expression system and two microelectrode voltage-clamp, we report the functional expression and the molecular, biophysical, and pharmacological characterization of the western honeybee's sodium channel (Apis Mellifera NaV1). The NaV1 channel is the primary target for pyrethroid insecticides in insect pests. We further report that the honeybee's channel is also sensitive to permethrin and fenvalerate, respectively type I and type II pyrethroid insecticides. Molecular docking of these insecticides revealed a binding site that is similar to sites previously identified in other insects. We describe in vitro and in silico tools that can be used to test chemical compounds. Our findings could be used to assess the risks that current and next generation pesticides pose to honeybee populations.

Neural organization and visual processing in the anterior optic tubercle of the honeybee brain.

PubMed

Mota, Theo; Yamagata, Nobuhiro; Giurfa, Martin; Gronenberg, Wulfila; Sandoz, Jean-Christophe

2011-08-10

The honeybee Apis mellifera represents a valuable model for studying the neural segregation and integration of visual information. Vision in honeybees has been extensively studied at the behavioral level and, to a lesser degree, at the physiological level using intracellular electrophysiological recordings of single neurons. However, our knowledge of visual processing in honeybees is still limited by the lack of functional studies of visual processing at the circuit level. Here we contribute to filling this gap by providing a neuroanatomical and neurophysiological characterization at the circuit level of a practically unstudied visual area of the bee brain, the anterior optic tubercle (AOTu). First, we analyzed the internal organization and neuronal connections of the AOTu. Second, we established a novel protocol for performing optophysiological recordings of visual circuit activity in the honeybee brain and studied the responses of AOTu interneurons during stimulation of distinct eye regions. Our neuroanatomical data show an intricate compartmentalization and connectivity of the AOTu, revealing a dorsoventral segregation of the visual input to the AOTu. Light stimuli presented in different parts of the visual field (dorsal, lateral, or ventral) induce distinct patterns of activation in AOTu output interneurons, retaining to some extent the dorsoventral input segregation revealed by our neuroanatomical data. In particular, activity patterns evoked by dorsal and ventral eye stimulation are clearly segregated into distinct AOTu subunits. Our results therefore suggest an involvement of the AOTu in the processing of dorsoventrally segregated visual information in the honeybee brain.

Estimating the density of honeybee colonies across their natural range to fill the gap in pollinator decline censuses.

PubMed

Jaffé, Rodolfo; Dietemann, Vincent; Allsopp, Mike H; Costa, Cecilia; Crewe, Robin M; Dall'olio, Raffaele; DE LA Rúa, Pilar; El-Niweiri, Mogbel A A; Fries, Ingemar; Kezic, Nikola; Meusel, Michael S; Paxton, Robert J; Shaibi, Taher; Stolle, Eckart; Moritz, Robin F A

2010-04-01

Although pollinator declines are a global biodiversity threat, the demography of the western honeybee (Apis mellifera) has not been considered by conservationists because it is biased by the activity of beekeepers. To fill this gap in pollinator decline censuses and to provide a broad picture of the current status of honeybees across their natural range, we used microsatellite genetic markers to estimate colony densities and genetic diversity at different locations in Europe, Africa, and central Asia that had different patterns of land use. Genetic diversity and colony densities were highest in South Africa and lowest in Northern Europe and were correlated with mean annual temperature. Confounding factors not related to climate, however, are also likely to influence genetic diversity and colony densities in honeybee populations. Land use showed a significantly negative influence over genetic diversity and the density of honeybee colonies over all sampling locations. In Europe honeybees sampled in nature reserves had genetic diversity and colony densities similar to those sampled in agricultural landscapes, which suggests that the former are not wild but may have come from managed hives. Other results also support this idea: putative wild bees were rare in our European samples, and the mean estimated density of honeybee colonies on the continent closely resembled the reported mean number of managed hives. Current densities of European honeybee populations are in the same range as those found in the adverse climatic conditions of the Kalahari and Saharan deserts, which suggests that beekeeping activities do not compensate for the loss of wild colonies. Our findings highlight the importance of reconsidering the conservation status of honeybees in Europe and of regarding beekeeping not only as a profitable business for producing honey, but also as an essential component of biodiversity conservation.

Honeybees, Butterflies, and Ladybugs: Partners to Plants

ERIC Educational Resources Information Center

Campbell, Ashley

2009-01-01

Honeybees, butterflies, and ladybugs all have fascinating mutually beneficial relationships with plants and play important ecosystem roles. Children also love these creatures. But how do we teach children about these symbiotic interactions and help them appreciate their vital roles in our environment? One must is to give children direct experience…

Evaluating exposure and potential effects on honeybee brood (Apis mellifera) development using glyphosate as an example

PubMed Central

Thompson, Helen M; Levine, Steven L; Doering, Janine; Norman, Steve; Manson, Philip; Sutton, Peter; von Mérey, Georg

2014-01-01

This study aimed to develop an approach to evaluate potential effects of plant protection products on honeybee brood with colonies at realistic worst-case exposure rates. The approach comprised 2 stages. In the first stage, honeybee colonies were exposed to a commercial formulation of glyphosate applied to flowering Phacelia tanacetifolia with glyphosate residues quantified in relevant matrices (pollen and nectar) collected by foraging bees on days 1, 2, 3, 4, and 7 postapplication and glyphosate levels in larvae were measured on days 4 and 7. Glyphosate levels in pollen were approximately 10 times higher than in nectar and glyphosate demonstrated rapid decline in both matrices. Residue data along with foraging rates and food requirements of the colony were then used to set dose rates in the effects study. In the second stage, the toxicity of technical glyphosate to developing honeybee larvae and pupae, and residues in larvae, were then determined by feeding treated sucrose directly to honeybee colonies at dose rates that reflect worst-case exposure scenarios. There were no significant effects from glyphosate observed in brood survival, development, and mean pupal weight. Additionally, there were no biologically significant levels of adult mortality observed in any glyphosate treatment group. Significant effects were observed only in the fenoxycarb toxic reference group and included increased brood mortality and a decline in the numbers of bees and brood. Mean glyphosate residues in larvae were comparable at 4 days after spray application in the exposure study and also following dosing at a level calculated from the mean measured levels in pollen and nectar, showing the applicability and robustness of the approach for dose setting with honeybee brood studies. This study has developed a versatile and predictive approach for use in higher tier honeybee toxicity studies. It can be used to realistically quantify exposure of colonies to pesticides to allow the

Evaluating exposure and potential effects on honeybee brood (Apis mellifera) development using glyphosate as an example.

PubMed

Thompson, Helen M; Levine, Steven L; Doering, Janine; Norman, Steve; Manson, Philip; Sutton, Peter; von Mérey, Georg

2014-07-01

This study aimed to develop an approach to evaluate potential effects of plant protection products on honeybee brood with colonies at realistic worst-case exposure rates. The approach comprised 2 stages. In the first stage, honeybee colonies were exposed to a commercial formulation of glyphosate applied to flowering Phacelia tanacetifolia with glyphosate residues quantified in relevant matrices (pollen and nectar) collected by foraging bees on days 1, 2, 3, 4, and 7 postapplication and glyphosate levels in larvae were measured on days 4 and 7. Glyphosate levels in pollen were approximately 10 times higher than in nectar and glyphosate demonstrated rapid decline in both matrices. Residue data along with foraging rates and food requirements of the colony were then used to set dose rates in the effects study. In the second stage, the toxicity of technical glyphosate to developing honeybee larvae and pupae, and residues in larvae, were then determined by feeding treated sucrose directly to honeybee colonies at dose rates that reflect worst-case exposure scenarios. There were no significant effects from glyphosate observed in brood survival, development, and mean pupal weight. Additionally, there were no biologically significant levels of adult mortality observed in any glyphosate treatment group. Significant effects were observed only in the fenoxycarb toxic reference group and included increased brood mortality and a decline in the numbers of bees and brood. Mean glyphosate residues in larvae were comparable at 4 days after spray application in the exposure study and also following dosing at a level calculated from the mean measured levels in pollen and nectar, showing the applicability and robustness of the approach for dose setting with honeybee brood studies. This study has developed a versatile and predictive approach for use in higher tier honeybee toxicity studies. It can be used to realistically quantify exposure of colonies to pesticides to allow the

Fighting Off Wound Pathogens in Horses with Honeybee Lactic Acid Bacteria.

PubMed

Olofsson, Tobias C; Butler, Éile; Lindholm, Christina; Nilson, Bo; Michanek, Per; Vásquez, Alejandra

2016-10-01

In the global perspective of antibiotic resistance, it is urgent to find potent topical antibiotics for the use in human and animal infection. Healing of equine wounds, particularly in the limbs, is difficult due to hydrostatic factors and exposure to environmental contaminants, which can lead to heavy bio-burden/biofilm formation and sometimes to infection. Therefore, antibiotics are often prescribed. Recent studies have shown that honeybee-specific lactic acid bacteria (LAB), involved in honey production, and inhibit human wound pathogens. The aim of this pilot study was to investigate the effects on the healing of hard-to-heal equine wounds after treatment with these LAB symbionts viable in a heather honey formulation. For this, we included ten horses with wound duration of >1 year, investigated the wound microbiota, and treated wounds with the novel honeybee LAB formulation. We identified the microbiota using MALDI-TOF mass spectrometry and DNA sequencing. In addition, the antimicrobial properties of the honeybee LAB formulation were tested against all wound isolates in vitro. Our results indicate a diverse wound microbiota including fifty-three bacterial species that showed 90 % colonization by at least one species of Staphylococcus. Treatment with the formulation promoted wound healing in all cases already after the first application and the wounds were either completely healed (n = 3) in less than 20 days or healing was in progress. Furthermore, the honeybee LAB formulation inhibited all pathogens when tested in vitro. Consequently, this new treatment option presents as a powerful candidate for the topical treatment of hard-to-heal wounds in horses.

Behavioral and Neurophysiological Study of Olfactory Perception and Learning in Honeybees

PubMed Central

Sandoz, Jean Christophe

2011-01-01

The honeybee Apis mellifera has been a central insect model in the study of olfactory perception and learning for more than a century, starting with pioneer work by Karl von Frisch. Research on olfaction in honeybees has greatly benefited from the advent of a range of behavioral and neurophysiological paradigms in the Lab. Here I review major findings about how the honeybee brain detects, processes, and learns odors, based on behavioral, neuroanatomical, and neurophysiological approaches. I first address the behavioral study of olfactory learning, from experiments on free-flying workers visiting artificial flowers to laboratory-based conditioning protocols on restrained individuals. I explain how the study of olfactory learning has allowed understanding the discrimination and generalization ability of the honeybee olfactory system, its capacity to grant special properties to olfactory mixtures as well as to retain individual component information. Next, based on the impressive amount of anatomical and immunochemical studies of the bee brain, I detail our knowledge of olfactory pathways. I then show how functional recordings of odor-evoked activity in the brain allow following the transformation of the olfactory message from the periphery until higher-order central structures. Data from extra- and intracellular electrophysiological approaches as well as from the most recent optical imaging developments are described. Lastly, I discuss results addressing how odor representation changes as a result of experience. This impressive ensemble of behavioral, neuroanatomical, and neurophysiological data available in the bee make it an attractive model for future research aiming to understand olfactory perception and learning in an integrative fashion. PMID:22163215

Transcriptome Analysis of Honeybee (Apis Mellifera) Haploid and Diploid Embryos Reveals Early Zygotic Transcription during Cleavage

PubMed Central

Pires, Camilla Valente; Freitas, Flávia Cristina de Paula; Cristino, Alexandre S.; Dearden, Peter K.; Simões, Zilá Luz Paulino

2016-01-01

In honeybees, the haplodiploid sex determination system promotes a unique embryogenesis process wherein females develop from fertilized eggs and males develop from unfertilized eggs. However, the developmental strategies of honeybees during early embryogenesis are virtually unknown. Similar to most animals, the honeybee oocytes are supplied with proteins and regulatory elements that support early embryogenesis. As the embryo develops, the zygotic genome is activated and zygotic products gradually replace the preloaded maternal material. The analysis of small RNA and mRNA libraries of mature oocytes and embryos originated from fertilized and unfertilized eggs has allowed us to explore the gene expression dynamics in the first steps of development and during the maternal-to-zygotic transition (MZT). We localized a short sequence motif identified as TAGteam motif and hypothesized to play a similar role in honeybees as in fruit flies, which includes the timing of early zygotic expression (MZT), a function sustained by the presence of the zelda ortholog, which is the main regulator of genome activation. Predicted microRNA (miRNA)-target interactions indicated that there were specific regulators of haploid and diploid embryonic development and an overlap of maternal and zygotic gene expression during the early steps of embryogenesis. Although a number of functions are highly conserved during the early steps of honeybee embryogenesis, the results showed that zygotic genome activation occurs earlier in honeybees than in Drosophila based on the presence of three primary miRNAs (pri-miRNAs) (ame-mir-375, ame-mir-34 and ame-mir-263b) during the cleavage stage in haploid and diploid embryonic development. PMID:26751956

Social learning of floral odours inside the honeybee hive.

PubMed

Farina, Walter M; Grüter, Christoph; Díaz, Paula C

2005-09-22

A honeybee hive serves as an information centre in which communication among bees allows the colony to exploit the most profitable resources in a continuously changing environment. The best-studied communication behaviour in this context is the waggle dance performed by returning foragers, which encodes information about the distance and direction to the food source. It has been suggested that another information cue, floral scents transferred within the hive, is also important for recruitment to food sources, as bee recruits are more strongly attracted to odours previously brought back by foragers in both honeybees and bumble-bees. These observations suggested that honeybees learn the odour from successful foragers before leaving the hive. However, this has never been shown directly and the mechanisms and properties of the learning process remain obscure. We tested the learning and memory of recruited bees in the laboratory using the proboscis extension response (PER) paradigm, and show that recruits indeed learn the nectar odours brought back by foragers by associative learning and retrieve this memory in the PER paradigm. The associative nature of this learning reveals that information was gained during mouth-to-mouth contacts among bees (trophallaxis). Results further suggest that the information is transferred to long-term memory. Associative learning of food odours in a social context may help recruits to find a particular food source faster.

MtDNA COI-COII marker and drone congregation area: an efficient method to establish and monitor honeybee (Apis mellifera L.) conservation centres.

PubMed

Bertrand, Bénédicte; Alburaki, Mohamed; Legout, Hélène; Moulin, Sibyle; Mougel, Florence; Garnery, Lionel

2015-05-01

Honeybee subspecies have been affected by human activities in Europe over the past few decades. One such example is the importation of nonlocal subspecies of bees which has had an adverse impact on the geographical repartition and subsequently on the genetic diversity of the black honeybee Apis mellifera mellifera. To restore the original diversity of this local honeybee subspecies, different conservation centres were set up in Europe. In this study, we established a black honeybee conservation centre Conservatoire de l'Abeille Noire d'Ile de France (CANIF) in the region of Ile-de-France, France. CANIF's honeybee colonies were intensively studied over a 3-year period. This study included a drone congregation area (DCA) located in the conservation centre. MtDNA COI-COII marker was used to evaluate the genetic diversity of CANIF's honeybee populations and the drones found and collected from the DCA. The same marker (mtDNA) was used to estimate the interactions and the haplotype frequency between CANIF's honeybee populations and 10 surrounding honeybee apiaries located outside of the CANIF. Our results indicate that the colonies of the conservation centre and the drones of the DCA show similar stable profiles compared to the surrounding populations with lower level of introgression. The mtDNA marker used on both DCA and colonies of the conservation centre seems to be an efficient approach to monitor and maintain the genetic diversity of the protected honeybee populations. © 2014 John Wiley & Sons Ltd.

Understanding the Logics of Pheromone Processing in the Honeybee Brain: From Labeled-Lines to Across-Fiber Patterns

PubMed Central

Sandoz, Jean-Christophe; Deisig, Nina; de Brito Sanchez, Maria Gabriela; Giurfa, Martin

2007-01-01

Honeybees employ a very rich repertoire of pheromones to ensure intraspecific communication in a wide range of behavioral contexts. This communication can be complex, since the same compounds can have a variety of physiological and behavioral effects depending on the receiver. Honeybees constitute an ideal model to study the neurobiological basis of pheromonal processing, as they are already one of the most influential animal models for the study of general odor processing and learning at behavioral, cellular and molecular levels. Accordingly, the anatomy of the bee brain is well characterized and electro- and opto-physiological recording techniques at different stages of the olfactory circuit are possible in the laboratory. Here we review pheromone communication in honeybees and analyze the different stages of olfactory processing in the honeybee brain, focusing on available data on pheromone detection, processing and representation at these different stages. In particular, we argue that the traditional distinction between labeled-line and across-fiber pattern processing, attributed to pheromone and general odors respectively, may not be so clear in the case of honeybees, especially for social-pheromones. We propose new research avenues for stimulating future work in this area. PMID:18958187

Sublethal effects of acaricides and Nosema ceranae infection on immune related gene expression in honeybees.

PubMed

Garrido, Paula Melisa; Porrini, Martín Pablo; Antúnez, Karina; Branchiccela, Belén; Martínez-Noël, Giselle María Astrid; Zunino, Pablo; Salerno, Graciela; Eguaras, Martín Javier; Ieno, Elena

2016-04-26

Nosema ceranae is an obligate intracellular parasite and the etiologic agent of Nosemosis that affects honeybees. Beside the stress caused by this pathogen, honeybee colonies are exposed to pesticides under beekeeper intervention, such as acaricides to control Varroa mites. These compounds can accumulate at high concentrations in apicultural matrices. In this work, the effects of parasitosis/acaricide on genes involved in honeybee immunity and survival were evaluated. Nurse bees were infected with N. ceranae and/or were chronically treated with sublethal doses of coumaphos or tau-fluvalinate, the two most abundant pesticides recorded in productive hives. Our results demonstrate the following: (1) honeybee survival was not affected by any of the treatments; (2) parasite development was not altered by acaricide treatments; (3) coumaphos exposure decreased lysozyme expression; (4) N. ceranae reduced levels of vitellogenin transcripts independently of the presence of acaricides. However, combined effects among stressors on imagoes were not recorded. Sublethal doses of acaricides and their interaction with other ubiquitous parasites in colonies, extending the experimental time, are of particular interest in further research work.

Honeybees Increase Fruit Set in Native Plant Species Important for Wildlife Conservation

NASA Astrophysics Data System (ADS)

Cayuela, Luis; Ruiz-Arriaga, Sarah; Ozers, Christian P.

2011-11-01

Honeybee colonies are declining in some parts of the world. This may have important consequences for the pollination of crops and native plant species. In Spain, as in other parts of Europe, land abandonment has led to a decrease in the number of non professional beekeepers, which aggravates the problem of honeybee decline as a result of bee diseases In this study, we investigated the effects of honeybees on the pollination of three native plant species in northern Spain, namely wildcherry Prunus avium L., hawthorn Crataegus monogyna Jacq., and bilberry Vaccinium myrtillus L. We quantified fruit set of individuals from the target species along transects established from an apiary outwards. Half the samples were bagged in a nylon mesh to avoid insect pollination. Mixed-effects models were used to test the effect of distance to the apiary on fruit set in non-bagged samples. The results showed a negative significant effect of distance from the apiary on fruit set for hawthorn and bilberry, but no significant effects were detected for wildcherry. This suggests that the use of honeybees under traditional farming practices might be a good instrument to increase fruit production of some native plants. This may have important consequences for wildlife conservation, since fruits, and bilberries in particular, constitute an important feeding resource for endangered species, such as the brown bear Ursus arctos L. or the capercaillie Tetrao urogallus cantabricus L.

Honeybees increase fruit set in native plant species important for wildlife conservation.

PubMed

Cayuela, Luis; Ruiz-Arriaga, Sarah; Ozers, Christian P

2011-11-01

Honeybee colonies are declining in some parts of the world. This may have important consequences for the pollination of crops and native plant species. In Spain, as in other parts of Europe, land abandonment has led to a decrease in the number of non professional beekeepers, which aggravates the problem of honeybee decline as a result of bee diseases In this study, we investigated the effects of honeybees on the pollination of three native plant species in northern Spain, namely wildcherry Prunus avium L., hawthorn Crataegus monogyna Jacq., and bilberry Vaccinium myrtillus L. We quantified fruit set of individuals from the target species along transects established from an apiary outwards. Half the samples were bagged in a nylon mesh to avoid insect pollination. Mixed-effects models were used to test the effect of distance to the apiary on fruit set in non-bagged samples. The results showed a negative significant effect of distance from the apiary on fruit set for hawthorn and bilberry, but no significant effects were detected for wild cherry. This suggests that the use of honeybees under traditional farming practices might be a good instrument to increase fruit production of some native plants. This may have important consequences for wildlife conservation, since fruits, and bilberries in particular, constitute an important feeding resource for endangered species, such as the brown bear Ursus arctos L. or the capercaillie Tetrao urogallus cantabricus L.

Honeybee (Apis mellifera ligustica) drone embryo proteomes.

PubMed

Li, Jianke; Fang, Yu; Zhang, Lan; Begna, Desalegn

2011-03-01

Little attention has been paid to the drone honeybee (Apis mellifera ligustica) which is a haploid individual carrying only the set of alleles that it inherits from its mother. Molecular mechanisms underlying drone embryogenesis are poorly understood. This study evaluated protein expression profiles of drone embryogenesis at embryonic ages of 24, 48 and 72h. More than 100 reproducible proteins were analyzed by mass spectrometry on 2D electrophoresis gels. Sixty-two proteins were significantly changed at the selected three experimental age points. Expression of the metabolic energy requirement-related protein peaked at the embryonic age of 48h, whereas development and metabolizing amino acid-related proteins expressed optimally at 72h. Cytoskeleton, protein folding and antioxidant-related proteins were highly expressed at 48 and 72h. Protein networks of the identified proteins were constructed and protein expressions were validated at the transcription level. This first proteomic study of drone embryogenesis in the honeybee may provide geneticists an exact timetable and candidate protein outline for further manipulations of drone stem cells. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Physiological State Influences the Social Interactions of Two Honeybee Nest Mates

PubMed Central

Wright, Geraldine A.; Lillvis, Joshua L.; Bray, Helen J.; Mustard, Julie A.

2012-01-01

Physiological state profoundly influences the expression of the behaviour of individuals and can affect social interactions between animals. How physiological state influences food sharing and social behaviour in social insects is poorly understood. Here, we examined the social interactions and food sharing behaviour of honeybees with the aim of developing the honeybee as a model for understanding how an individual's state influences its social interactions. The state of individual honeybees was manipulated by either starving donor bees or feeding them sucrose or low doses of ethanol to examine how a change in hunger or inebriation state affected the social behaviours exhibited by two closely-related nestmates. Using a lab-based assay for measuring individual motor behaviour and social behaviour, we found that behaviours such as antennation, willingness to engage in trophallaxis, and mandible opening were affected by both hunger and ethanol intoxication. Inebriated bees were more likely to exhibit mandible opening, which may represent a form of aggression, than bees fed sucrose alone. However, intoxicated bees were as willing to engage in trophallaxis as the sucrose-fed bees. The effects of ethanol on social behaviors were dose-dependent, with higher doses of ethanol producing larger effects on behaviour. Hungry donor bees, on the other hand, were more likely to engage in begging for food and less likely to antennate and to display mandible opening. We also found that when nestmates received food from donors previously fed ethanol, they began to display evidence of inebriation, indicating that ethanol can be retained in the crop for several hours and that it can be transferred between honeybee nestmates during trophallaxis. PMID:22427864

Mechanism of action of recombinant Acc-royalisin from royal jelly of Chinese honeybee against gram-positive bacteria

USDA-ARS?s Scientific Manuscript database

The antibacterial activity of royalisin, an antimicrobial peptide from the royal jelly produced by honeybees has been addressed extensively. However, its mechanism of action remains unclear. In this study, a recombinant royalisin, RAcc-royalisin from the royal jelly of Chinese honeybee Apis cerana...

Effects of erectable glossal hairs on a honeybee's nectar-drinking strategy

NASA Astrophysics Data System (ADS)

Yang, Heng; Wu, Jianing; Yan, Shaoze

2014-06-01

With the use of a scanning electron microscope, we observe specific microstructures of the mouthpart of the Italian bee (Apis mellifera ligustica), especially the distribution and dimensions of hairs on its glossa. Considering the erection of glossal hairs for trapping nectar modifies the viscous dipping model in analyzing the drinking strategy of a honeybee. Theoretical estimations of volume intake rates with respect to sucrose solutions of different concentrations agree with experimental data, which indicates that erectable hairs can significantly increase the ability of a bee to acquire nectar efficiently. The comparison with experimental results also indicates that a honeybee may continuously augment its pumping power, rather than keep it constant, to drink nectar with sharply increasing viscosity. Under the modified assumption of increasing working power, we introduce the rate at which working power increases with viscosity and discuss the nature-preferred nectar concentration of 35% by theoretically calculating optimal concentration maximizing energetic intake rates under varying increasing rates. Finally, the ability of the mouthparts of the honeybee to transfer viscous nectar may inspire a concept for transporting microfluidics with a wide range of viscosities.

Plant origin of Okinawan propolis: honeybee behavior observation and phytochemical analysis

NASA Astrophysics Data System (ADS)

Kumazawa, Shigenori; Nakamura, Jun; Murase, Masayo; Miyagawa, Mariko; Ahn, Mok-Ryeon; Fukumoto, Shuichi

2008-08-01

Propolis is a natural resinous product collected by honeybees from certain plants. It has gained popularity as a food and alternative medicine. Poplar and Baccharis are well known as the source plants of European and Brazilian propolis, respectively. However, the propolis from Okinawa, Japan, contains some prenylflavonoids not seen in other regions such as Europe and Brazil, suggesting that the plant origin of Okinawan propolis is a particular plant that grows in Okinawa. To identify the plant origin of Okinawan propolis, we observed the behavior of honeybees as they collected material from plants and caulked it inside the hive. Honeybees scraped resinous material from the surface of plant fruits of Macaranga tanarius and brought it back to their hive to use it as propolis. We collected samples of the plant and propolis, and compared their constituents by high-performance liquid chromatography with a photo-diode array detector. We also compared their 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity. The chemical constituents and biological activity of the ethanol extracts of the plant did not differ from those of propolis. This indicates directly that the plant origin of Okinawan propolis is M. tanarius.

Energy saving strategies of honeybees in dipping nectar

PubMed Central

Wu, Jianing; Yang, Heng; Yan, Shaoze

2015-01-01

The honeybee’s drinking process has generally been simplified because of its high speed and small scale. In this study, we clearly observed the drinking cycle of the Italian honeybee using a specially designed high-speed camera system. We analysed the pattern of glossal hair erection and the movement kinematics of the protracting tongue (glossa). Results showed that the honeybee used two special protraction strategies to save energy. First, the glossal hairs remain adpressed until the end of the protraction, which indicates that the hydraulic resistance is reduced to less than 1/3 of that in the case if the hairs remain erect. Second, the glossa protracts with a specific velocity profile and we quantitatively demonstrated that this moving strategy helps reduce the total energy needed for protraction compared with the typical form of protraction with constant acceleration and deceleration. These findings suggest effective methods to optimise the control policies employed by next-generation microfluidic pumps. PMID:26446300

Modeling colony collapse disorder in honeybees as a contagion.

PubMed

Kribs-Zaleta, Christopher M; Mitchell, Christopher

2014-12-01

Honeybee pollination accounts annually for over $14 billion in United States agriculture alone. Within the past decade there has been a mysterious mass die-off of honeybees, an estimated 10 million beehives and sometimes as much as 90% of an apiary. There is still no consensus on what causes this phenomenon, called Colony Collapse Disorder, or CCD. Several mathematical models have studied CCD by only focusing on infection dynamics. We created a model to account for both healthy hive dynamics and hive extinction due to CCD, modeling CCD via a transmissible infection brought to the hive by foragers. The system of three ordinary differential equations accounts for multiple hive population behaviors including Allee effects and colony collapse. Numerical analysis leads to critical hive sizes for multiple scenarios and highlights the role of accelerated forager recruitment in emptying hives during colony collapse.

Morphofunctional Experience-Dependent Plasticity in the Honeybee Brain

ERIC Educational Resources Information Center

Andrione, Mara; Timberlake, Benjamin F.; Vallortigara, Giorgio; Antolini, Renzo; Haase, Albrecht

2017-01-01

Repeated or prolonged exposure to an odorant without any positive or negative reinforcement produces experience-dependent plasticity, which results in habituation and latent inhibition. In the honeybee ("Apis mellifera"), it has been demonstrated that, even if the absolute neural representation of an odor in the primary olfactory center,…

From honeybees to Internet servers: biomimicry for distributed management of Internet hosting centers.

PubMed

Nakrani, Sunil; Tovey, Craig

2007-12-01

An Internet hosting center hosts services on its server ensemble. The center must allocate servers dynamically amongst services to maximize revenue earned from hosting fees. The finite server ensemble, unpredictable request arrival behavior and server reallocation cost make server allocation optimization difficult. Server allocation closely resembles honeybee forager allocation amongst flower patches to optimize nectar influx. The resemblance inspires a honeybee biomimetic algorithm. This paper describes details of the honeybee self-organizing model in terms of information flow and feedback, analyzes the homology between the two problems and derives the resulting biomimetic algorithm for hosting centers. The algorithm is assessed for effectiveness and adaptiveness by comparative testing against benchmark and conventional algorithms. Computational results indicate that the new algorithm is highly adaptive to widely varying external environments and quite competitive against benchmark assessment algorithms. Other swarm intelligence applications are briefly surveyed, and some general speculations are offered regarding their various degrees of success.

Amtyr1: characterization of a gene from honeybee (Apis mellifera) brain encoding a functional tyramine receptor.

PubMed

Blenau, W; Balfanz, S; Baumann, A

2000-03-01

Biogenic amine receptors are involved in the regulation and modulation of various physiological and behavioral processes in both vertebrates and invertebrates. We have cloned a member of this gene family from the CNS of the honeybee, Apis mellifera. The deduced amino acid sequence is homologous to tyramine receptors cloned from Locusta migratoria and Drosophila melanogaster as well as to an octopamine receptor cloned from Heliothis virescens. Functional properties of the honeybee receptor were studied in stably transfected human embryonic kidney 293 cells. Tyramine reduced forskolin-induced cyclic AMP production in a dose-dependent manner with an EC50 of approximately 130 nM. A similar effect of tyramine was observed in membrane homogenates of honeybee brains. Octopamine also reduced cyclic AMP production in the transfected cell line but was both less potent (EC50 of approximately 3 microM) and less efficacious than tyramine. Receptor-encoding mRNA has a wide-spread distribution in the brain and subesophageal ganglion of the honeybee, suggesting that this tyramine receptor is involved in sensory signal processing as well as in higher-order brain functions.

Biased gene expression in early honeybee larval development

PubMed Central

2013-01-01

Background Female larvae of the honeybee (Apis mellifera) develop into either queens or workers depending on nutrition. This nutritional stimulus triggers different developmental trajectories, resulting in adults that differ from each other in physiology, behaviour and life span. Results To understand how these trajectories are established we have generated a comprehensive atlas of gene expression throughout larval development. We found substantial differences in gene expression between worker and queen-destined larvae at 6 hours after hatching. Some of these early changes in gene expression are maintained throughout larval development, indicating that caste-specific developmental trajectories are established much earlier than previously thought. Within our gene expression data we identified processes that potentially underlie caste differentiation. Queen-destined larvae have higher expression of genes involved in transcription, translation and protein folding early in development with a later switch to genes involved in energy generation. Using RNA interference, we were able to demonstrate that one of these genes, hexamerin 70b, has a role in caste differentiation. Both queen and worker developmental trajectories are associated with the expression of genes that have alternative splice variants, although only a single variant of a gene tends to be differentially expressed in a given caste. Conclusions Our data, based on the biases in gene expression early in development together with published data, supports the idea that caste development in the honeybee consists of two phases; an initial biased phase of development, where larvae can still switch to the other caste by differential feeding, followed by commitment to a particular developmental trajectory. PMID:24350621

An Early Sensitive Period Induces Long-Lasting Plasticity in the Honeybee Nervous System

PubMed Central

Grosso, Juan P.; Barneto, Jesica A.; Velarde, Rodrigo A.; Pagano, Eduardo A.; Zavala, Jorge A.; Farina, Walter M.

2018-01-01

The effect of early experiences on the brain during a sensitive period exerts a long-lasting influence on the mature individual. Despite behavioral and neural plasticity caused by early experiences having been reported in the honeybee Apis mellifera, the presence of a sensitive period in which associative experiences lead to pronounced modifications in the adult nervous system is still unclear. Laboratory-reared bees were fed with scented food within specific temporal windows and were assessed for memory retention, in the regulation of gene expression related to the synaptic formation and in the olfactory perception of their antennae at 17 days of age. Bees were able to retain a food-odor association acquired 5–8 days after emergence, but not before, and showed better retention than those exposed to an odor at 9–12 days. In the brain, the odor-rewarded experiences that occurred at 5–8 days of age boosted the expression levels of the cell adhesion proteins neurexin 1 (Nrx1) and neuroligin 2 (Nlg2) involved in synaptic strength. At the antennae, the experiences increased the electrical response to a novel odor but not to the one experienced. Therefore, a sensitive period that induces long-lasting behavioral, functional and structural changes is found in adult honeybees. PMID:29449804

An Early Sensitive Period Induces Long-Lasting Plasticity in the Honeybee Nervous System.

PubMed

Grosso, Juan P; Barneto, Jesica A; Velarde, Rodrigo A; Pagano, Eduardo A; Zavala, Jorge A; Farina, Walter M

2018-01-01

The effect of early experiences on the brain during a sensitive period exerts a long-lasting influence on the mature individual. Despite behavioral and neural plasticity caused by early experiences having been reported in the honeybee Apis mellifera , the presence of a sensitive period in which associative experiences lead to pronounced modifications in the adult nervous system is still unclear. Laboratory-reared bees were fed with scented food within specific temporal windows and were assessed for memory retention, in the regulation of gene expression related to the synaptic formation and in the olfactory perception of their antennae at 17 days of age. Bees were able to retain a food-odor association acquired 5-8 days after emergence, but not before, and showed better retention than those exposed to an odor at 9-12 days. In the brain, the odor-rewarded experiences that occurred at 5-8 days of age boosted the expression levels of the cell adhesion proteins neurexin 1 ( Nrx1 ) and neuroligin 2 ( Nlg2 ) involved in synaptic strength. At the antennae, the experiences increased the electrical response to a novel odor but not to the one experienced. Therefore, a sensitive period that induces long-lasting behavioral, functional and structural changes is found in adult honeybees.

Biomonitoring, status and source risk assessment of polycyclic aromatic hydrocarbons (PAHs) using honeybees, pine tree leaves, and propolis.

PubMed

Kargar, Navid; Matin, Golnar; Matin, Amir Abbas; Buyukisik, Hasan Baha

2017-11-01

In this study, to identify and quantify the sources of airborne polycyclic aromatic hydrocarbons (PAHs), we gathered honeybee, pine tree leaf, and propolis samples to serve as bioindicators from five stations in the village of "Bozkoy" in the Aliaga industrial district of Izmir (Turkey) during April-May 2014. The PAH concentrations which measured by gas chromatography (GC) varied from 261.18 to 553.33 μg kg -1 dry weight (dw) in honeybee samples, 138.57-853.67 μg kg -1 dw in pine leaf samples, and 798.61-2905.53 μg kg -1 dw in propolis samples. The total PAH concentrations can be ranked as follows: propolis > pine leaves > honeybees. The ring sequence pattern was 5 > 3 > 6 > 4 > 2 for honeybees, 5 > 3 > 4 > 6 > 2 for pine leaves, and 5 > 4 > 6 > 3 > 2 for propolis. The diagnostic ratios [fluoranthene/fluoranthene + pyrene], [indeno(1,2,3-c,d)pyrene/indeno(1,2,3-c,d)pyrene + benzo(g,h,i)perylene], and [benzo(a)anthracene/benzo(a)anthracene + chrysene] indicate coal and biomass combustion to be the dominant PAH source in the study area. In biomonitoring studies of airborne PAHs based on honeybees, fluoranthene is considered to be a characteristic PAH compound. Distribution maps with different numbers of PAH rings among the sampling sites show the advantages of honeybee samples as indicators due to the honeybee's provision of a broader range of information with respect to heavier pollutants that are typically not in the gas or suspended phase for long periods of time. Our correlation, factor analysis, and principal components analysis (PCA) results indicate potential sources of PAH pollution in pine leaves and honeybees from airborne emissions, but we found propolis to be contaminated by PAHs due to the replacement of herbal sources of resins with synthetic gummy substances from paving materials (e.g., asphalt and tar leaks). Copyright © 2017 Elsevier Ltd. All rights reserved.

Mathematical analysis of the honeybee waggle dance.

PubMed

Okada, R; Ikeno, H; Kimura, T; Ohashi, Mizue; Aonuma, H; Ito, E

2012-01-01

A honeybee informs her nestmates of the location of a flower by doing a waggle dance. The waggle dance encodes both the direction of and distance to the flower from the hive. To reveal how the waggle dance benefits the colony, we created a Markov model of bee foraging behavior and performed simulation experiments by incorporating the biological parameters that we obtained from our own observations of real bees as well as from the literature. When two feeders were each placed 400 m away from the hive in different directions, a virtual colony in which honeybees danced and correctly transferred information (a normal, real bee colony) made significantly greater numbers of successful visits to the feeders compared to a colony with inaccurate information transfer. Howerer, when five feeders were each located 400 m from the hive, the inaccurate information transfer colony performed better than the normal colony. These results suggest that dancing's ability to communicate accurate information depends on the number of feeders. Furthermore, because non-dancing colonies always made significantly fewer visits than those two colonies, we concluded that dancing behavior is beneficial for hives' ability to visit food sources.

Odour concentration affects odour identity in honeybees

PubMed Central

Wright, Geraldine A; Thomson, Mitchell G.A; Smith, Brian H

2005-01-01

The fact that most types of sensory stimuli occur naturally over a large range of intensities is a challenge to early sensory processing. Sensory mechanisms appear to be optimized to extract perceptually significant stimulus fluctuations that can be analysed in a manner largely independent of the absolute stimulus intensity. This general principle may not, however, extend to olfaction; many studies have suggested that olfactory stimuli are not perceptually invariant with respect to odour intensity. For many animals, absolute odour intensity may be a feature in itself, such that it forms a part of odour identity and thus plays an important role in discrimination alongside other odour properties such as the molecular identity of the odorant. The experiments with honeybees reported here show a departure from odour-concentration invariance and are consistent with a lower-concentration regime in which odour concentration contributes to overall odour identity and a higher-concentration regime in which it may not. We argue that this could be a natural consequence of odour coding and suggest how an ‘intensity feature’ might be useful to the honeybee in natural odour detection and discrimination. PMID:16243694

Chemicals involved in honeybee-sunflower relationship.

PubMed

Pham-Delegue, M H; Etievant, P; Guichard, E; Marilleau, R; Douault, P; Chauffaille, J; Masson, C

1990-11-01

We present a review of work on the plant chemicals involved in the honeybee-sunflower model system. Combined behavioral and chemical analyses were conducted under natural and controlled conditions. First the distribution of forager bees' visits on two pairs of sunflower genotypes producing a different level of hybrid seed yield was recorded under pollen-proof tunnels. Mirasol parental lines producing high seed yields were visited at random, whereas forager bees visited preferentially the female parental line of Marianne, resulting in low seed yield. Nectar samples collected on the genotypes were analyzed by gas chromatography. Fructose, glucose, and sucrose were identified. Parental lines of Mirasol showed similar sugar profiles, whereas the female line of Marianne contained higher amounts of sucrose than the male line. We assume that the bees' preferences between genotypes might rely on differences in the sugar composition of floral nectars, especially in the amount of sucrose. Aromas from headspace collection were compared between pairs and periodically during the flowering period. Of the 144 components indexed for Marianne lines and 136 components for Mirasol lines, 17 of the components for Marianne lines and 18 for Mirasol lines differed significantly according to flowering stage. Significant differences appeared in eight of the 134 components of Marianne lines and in 20 of the 250 components for Mirasol lines. Such differences, even restricted to a few components, might account for honeybees' discrimination between genotypes or flowering stage. Experiments then were conducted in a flight room using an artificial flower device. A total volatile extract was used as a conditioning scent previous to the test where the total extract was successively compared to several of its subfractions. Fractions significantly less visited than the total extract were discarded, whereas fractions confused with the total extract were kept. From step to step, a restricted fraction

Associative Learning during Early Adulthood Enhances Later Memory Retention in Honeybees

PubMed Central

Arenas, Andrés; Fernández, Vanesa M.; Farina, Walter M.

2009-01-01

Background Cognitive experiences during the early stages of life play an important role in shaping the future behavior in mammals but also in insects, in which precocious learning can directly modify behaviors later in life depending on both the timing and the rearing environment. However, whether olfactory associative learning acquired early in the adult stage of insects affect memorizing of new learning events has not been studied yet. Methodology Groups of adult honeybee workers that experienced an odor paired with a sucrose solution 5 to 8 days or 9 to 12 days after emergence were previously exposed to (i) a rewarded experience through the offering of scented food, or (ii) a non-rewarded experience with a pure volatile compound in the rearing environment. Principal Findings Early rewarded experiences (either at 1–4 or 5–8 days of adult age) enhanced retention performance in 9–12-day-conditioned bees when they were tested at 17 days of age. The highest retention levels at this age, which could not be improved with prior rewarded experiences, were found for memories established at 5–8 days of adult age. Associative memories acquired at 9–12 days of age showed a weak effect on retention for some pure pre-exposed volatile compounds; whereas the sole exposure of an odor at any younger age did not promote long-term effects on learning performance. Conclusions The associative learning events that occurred a few days after adult emergence improved memorizing in middle-aged bees. In addition, both the timing and the nature of early sensory inputs interact to enhance retention of new learning events acquired later in life, an important matter in the social life of honeybees. PMID:19956575

Effectiveness of tilmicosin against Paenibacillus larvae, the causal agent of American Foulbrood disease of honeybees.

PubMed

Reynaldi, Francisco J; Albo, Graciela N; Alippi, Adriana M

2008-11-25

American Foulbrood (AFB) of honeybees (Apis mellifera L.), caused by the Gram-positive bacterium Paenibacillus larvae is one of the most serious diseases affecting the larval and pupal stages of honeybees (A. mellifera L.). The aim of the present work was to asses the response of 23 strains of P. larvae from diverse geographical origins to tilmicosin, a macrolide antibiotic developed for exclusive use in veterinary medicine, by means of the minimal inhibitory concentration (MIC) and the agar diffusion test (ADT). All the strains tested were highly susceptible to tilmicosin with MIC values ranging between 0.0625 and 0.5 microg ml(-1), and with MIC(50) and MIC(90) values of 0.250 microg ml(-1). The ADT tests results for 23 P. larvae strains tested showed that all were susceptible to tilmicosin with inhibition zones around 15 microg tilmicosin disks ranging between 21 and 50mm in diameter. Oral acute toxicity of tilmicosin was evaluated and the LD(50) values obtained demonstrated that it was virtually non-toxic for adult bees and also resulted non-toxic for larvae when compared with the normal brood mortality. Dosage of 1000 mg a.i. of tilmicosin applied in a 55 g candy resulted in a total suppression of AFB clinical signs in honeybee colonies 60 days after initial treatment. To our knowledge, this is the first report of the effectiveness of tilmicosin against P. larvae both in vitro and in vivo.

Pharmacologic inhibition of phospholipase C in the brain attenuates early memory formation in the honeybee (Apis mellifera L.)

PubMed Central

Iino, Shiori; Kubo, Takeo

2018-01-01

ABSTRACT Although the molecular mechanisms involved in learning and memory in insects have been studied intensively, the intracellular signaling mechanisms involved in early memory formation are not fully understood. We previously demonstrated that phospholipase C epsilon (PLCe), whose product is involved in calcium signaling, is almost selectively expressed in the mushroom bodies, a brain structure important for learning and memory in the honeybee. Here, we pharmacologically examined the role of phospholipase C (PLC) in learning and memory in the honeybee. First, we identified four genes for PLC subtypes in the honeybee genome database. Quantitative reverse transcription-polymerase chain reaction revealed that, among these four genes, three, including PLCe, were expressed higher in the brain than in sensory organs in worker honeybees, suggesting their main roles in the brain. Edelfosine and neomycin, pan-PLC inhibitors, significantly decreased PLC activities in homogenates of the brain tissues. These drugs injected into the head of foragers significantly attenuated memory acquisition in comparison with the control groups, whereas memory retention was not affected. These findings suggest that PLC in the brain is involved in early memory formation in the honeybee. To our knowledge, this is the first report of a role for PLC in learning and memory in an insect. PMID:29330349

Spider movement, UV reflectance and size, but not spider crypsis, affect the response of honeybees to Australian crab spiders.

PubMed

Llandres, Ana L; Rodríguez-Gironés, Miguel A

2011-02-16

According to the crypsis hypothesis, the ability of female crab spiders to change body colour and match the colour of flowers has been selected because flower visitors are less likely to detect spiders that match the colour of the flowers used as hunting platform. However, recent findings suggest that spider crypsis plays a minor role in predator detection and some studies even showed that pollinators can become attracted to flowers harbouring Australian crab spider when the UV contrast between spider and flower increases. Here we studied the response of Apis mellifera honeybees to the presence of white or yellow Thomisus spectabilis Australian crab spiders sitting on Bidens alba inflorescences and also the response of honeybees to crab spiders that we made easily detectable painting blue their forelimbs or abdomen. To account for the visual systems of crab spider's prey, we measured the reflectance properties of the spiders and inflorescences used for the experiments. We found that honeybees did not respond to the degree of matching between spiders and inflorescences (either chromatic or achromatic contrast): they responded similarly to white and yellow spiders, to control and painted spiders. However spider UV reflection, spider size and spider movement determined honeybee behaviour: the probability that honeybees landed on spider-harbouring inflorescences was greatest when the spiders were large and had high UV reflectance or when spiders were small and reflected little UV, and honeybees were more likely to reject inflorescences if spiders moved as the bee approached the inflorescence. Our study suggests that only the large, but not the small Australian crab spiders deceive their preys by reflecting UV light, and highlights the importance of other cues that elicited an anti-predator response in honeybees.

The endangered Iris atropurpurea (Iridaceae) in Israel: honey-bees, night-sheltering male bees and female solitary bees as pollinators.

PubMed

Watts, Stella; Sapir, Yuval; Segal, Bosmat; Dafni, Amots

2013-03-01

The coastal plain of Israel hosts the last few remaining populations of the endemic Iris atropurpurea (Iridaceae), a Red List species of high conservation priority. The flowers offer no nectar reward. Here the role of night-sheltering male solitary bees, honey-bees and female solitary bees as pollinators of I. atropurpurea is documented. Breeding system, floral longevity, stigma receptivity, visitation rates, pollen loads, pollen deposition and removal and fruit- and seed-set were investigated. The main wild pollinators of this plant are male eucerine bees, and to a lesser extent, but with the potential to transfer pollen, female solitary bees. Honey-bees were found to be frequent diurnal visitors; they removed large quantities of pollen and were as effective as male sheltering bees at pollinating this species. The low density of pollen carried by male solitary bees was attributed to grooming activities, pollen displacement when bees aggregated together in flowers and pollen depletion by honey-bees. In the population free of honey-bee hives, male bees carried significantly more pollen grains on their bodies. Results from pollen analysis and pollen deposited on stigmas suggest that inadequate pollination may be an important factor limiting fruit-set. In the presence of honey-bees, eucerine bees were low removal-low deposition pollinators, whereas honey-bees were high removal-low deposition pollinators, because they removed large amounts into corbiculae and deposited relatively little onto receptive stigmas. Even though overall, both bee taxa were equally effective pollinators, we suggest that honey-bees have the potential to reduce the amount of pollen available for plant reproduction, and to reduce the amount of resources available to solitary bee communities. The results of this study have potential implications for the conservation of this highly endangered plant species if hives are permitted inside reserves, where the bulk of Oncocyclus iris species are

Spider Movement, UV Reflectance and Size, but Not Spider Crypsis, Affect the Response of Honeybees to Australian Crab Spiders

PubMed Central

Llandres, Ana L.; Rodríguez-Gironés, Miguel A.

2011-01-01

According to the crypsis hypothesis, the ability of female crab spiders to change body colour and match the colour of flowers has been selected because flower visitors are less likely to detect spiders that match the colour of the flowers used as hunting platform. However, recent findings suggest that spider crypsis plays a minor role in predator detection and some studies even showed that pollinators can become attracted to flowers harbouring Australian crab spider when the UV contrast between spider and flower increases. Here we studied the response of Apis mellifera honeybees to the presence of white or yellow Thomisus spectabilis Australian crab spiders sitting on Bidens alba inflorescences and also the response of honeybees to crab spiders that we made easily detectable painting blue their forelimbs or abdomen. To account for the visual systems of crab spider's prey, we measured the reflectance properties of the spiders and inflorescences used for the experiments. We found that honeybees did not respond to the degree of matching between spiders and inflorescences (either chromatic or achromatic contrast): they responded similarly to white and yellow spiders, to control and painted spiders. However spider UV reflection, spider size and spider movement determined honeybee behaviour: the probability that honeybees landed on spider-harbouring inflorescences was greatest when the spiders were large and had high UV reflectance or when spiders were small and reflected little UV, and honeybees were more likely to reject inflorescences if spiders moved as the bee approached the inflorescence. Our study suggests that only the large, but not the small Australian crab spiders deceive their preys by reflecting UV light, and highlights the importance of other cues that elicited an anti-predator response in honeybees. PMID:21359183

The use of honeybees reared in a thermostatic chamber for aging studies.

PubMed

Hsu, Chin-Yuan; Chan, Yu-Pei

2013-02-01

Honeybees (Apis mellifera) are an attractive model system for studying aging. However, the aging level of worker honeybees from the field hive is in dispute. To eliminate the influence of task performance and confirm the relationship between chronological age and aging, we reared newly emerged workers in a thermostat at 34°C throughout their lives. A survivorship curve was obtained, indicating that workers can be reared away from the field hive, and the only difference between these workers is age. To confirm that these workers can be used for aging studies, we assayed age-related molecules in the trophocytes and fat cells of young and old workers. Old workers expressed more senescence-associated β-galactosidase, lipofuscin granules, lipid peroxidation, and protein oxidation than young workers. Furthermore, cellular energy metabolism molecules were also assayed. Old workers exhibited less ATP concentration, β-oxidation, and microtubule-associated protein light chain 3 (LC3) than young workers. These results demonstrate that honeybees reared in a thermostatic chamber can be used for aging studies and cellular energy metabolism in the trophocytes and fat cells of workers changes with advancing age.

Genetics of reproduction and regulation of honeybee (Apis mellifera L.) social behavior.

PubMed

Page, Robert E; Rueppell, Olav; Amdam, Gro V

2012-01-01

Honeybees form complex societies with a division of labor for reproduction, nutrition, nest construction and maintenance, and defense. How does it evolve? Tasks performed by worker honeybees are distributed in time and space. There is no central control over behavior and there is no central genome on which selection can act and effect adaptive change. For 22 years, we have been addressing these questions by selecting on a single social trait associated with nutrition: the amount of surplus pollen (a source of protein) that is stored in the combs of the nest. Forty-two generations of selection have revealed changes at biological levels extending from the society down to the level of the gene. We show how we constructed this vertical understanding of social evolution using behavioral and anatomical analyses, physiology, genetic mapping, and gene knockdowns. We map out the phenotypic and genetic architectures of food storage and foraging behavior and show how they are linked through broad epistasis and pleiotropy affecting a reproductive regulatory network that influences foraging behavior. This is remarkable because worker honeybees have reduced reproductive organs and are normally sterile; however, the reproductive regulatory network has been co-opted for behavioral division of labor.

Thelytokous Parthenogenesis in Unmated Queen Honeybees (Apis mellifera capensis): Central Fusion and High Recombination Rates

PubMed Central

Oldroyd, Benjamin P.; Allsopp, Michael H.; Gloag, Rosalyn S.; Lim, Julianne; Jordan, Lyndon A.; Beekman, Madeleine

2008-01-01

The subspecies of honeybee indigenous to the Cape region of South Africa, Apis mellifera capensis, is unique because a high proportion of unmated workers can lay eggs that develop into females via thelytokous parthenogenesis involving central fusion of meiotic products. This ability allows pseudoclonal lineages of workers to establish, which are presently widespread as reproductive parasites within the honeybee populations of South Africa. Successful long-term propagation of a parthenogen requires the maintenance of heterozygosity at the sex locus, which in honeybees must be heterozygous for the expression of female traits. Thus, in successful lineages of parasitic workers, recombination events are reduced by an order of magnitude relative to meiosis in queens of other honeybee subspecies. Here we show that in unmated A. m. capensis queens treated to induce oviposition, no such reduction in recombination occurs, indicating that thelytoky and reduced recombination are not controlled by the same gene. Our virgin queens were able to lay both arrhenotokous male-producing haploid eggs and thelytokous female-producing diploid eggs at the same time, with evidence that they have some voluntary control over which kind of egg was laid. If so, they are able to influence the kind of second-division meiosis that occurs in their eggs post partum. PMID:18716331

Synergistic Parasite-Pathogen Interactions Mediated by Host Immunity Can Drive the Collapse of Honeybee Colonies

PubMed Central

Nazzi, Francesco; Brown, Sam P.; Annoscia, Desiderato; Del Piccolo, Fabio; Di Prisco, Gennaro; Varricchio, Paola; Della Vedova, Giorgio; Cattonaro, Federica; Caprio, Emilio; Pennacchio, Francesco

2012-01-01

The health of the honeybee and, indirectly, global crop production are threatened by several biotic and abiotic factors, which play a poorly defined role in the induction of widespread colony losses. Recent descriptive studies suggest that colony losses are often related to the interaction between pathogens and other stress factors, including parasites. Through an integrated analysis of the population and molecular changes associated with the collapse of honeybee colonies infested by the parasitic mite Varroa destructor, we show that this parasite can de-stabilise the within-host dynamics of Deformed wing virus (DWV), transforming a cryptic and vertically transmitted virus into a rapidly replicating killer, which attains lethal levels late in the season. The de-stabilisation of DWV infection is associated with an immunosuppression syndrome, characterized by a strong down-regulation of the transcription factor NF-κB. The centrality of NF-κB in host responses to a range of environmental challenges suggests that this transcription factor can act as a common currency underlying colony collapse that may be triggered by different causes. Our results offer an integrated account for the multifactorial origin of honeybee losses and a new framework for assessing, and possibly mitigating, the impact of environmental challenges on honeybee health. PMID:22719246

On the Front Line: Quantitative Virus Dynamics in Honeybee (Apis mellifera L.) Colonies along a New Expansion Front of the Parasite Varroa destructor

PubMed Central

Mondet, Fanny; de Miranda, Joachim R.; Kretzschmar, Andre; Le Conte, Yves; Mercer, Alison R.

2014-01-01

Over the past fifty years, annual honeybee (Apis mellifera) colony losses have been steadily increasing worldwide. These losses have occurred in parallel with the global spread of the honeybee parasite Varroa destructor. Indeed, Varroa mite infestations are considered to be a key explanatory factor for the widespread increase in annual honeybee colony mortality. The host-parasite relationship between honeybees and Varroa is complicated by the mite's close association with a range of honeybee viral pathogens. The 10-year history of the expanding front of Varroa infestation in New Zealand offered a rare opportunity to assess the dynamic quantitative and qualitative changes in honeybee viral landscapes in response to the arrival, spread and level of Varroa infestation. We studied the impact of de novo infestation of bee colonies by Varroa on the prevalence and titres of seven well-characterised honeybee viruses in both bees and mites, using a large-scale molecular ecology approach. We also examined the effect of the number of years since Varroa arrival on honeybee and mite viral titres. The dynamic shifts in the viral titres of black queen cell virus and Kashmir bee virus mirrored the patterns of change in Varroa infestation rates along the Varroa expansion front. The deformed wing virus (DWV) titres in bees continued to increase with Varroa infestation history, despite dropping infestation rates, which could be linked to increasing DWV titres in the mites. This suggests that the DWV titres in mites, perhaps boosted by virus replication, may be a major factor in maintaining the DWV epidemic after initial establishment. Both positive and negative associations were identified for several pairs of viruses, in response to the arrival of Varroa. These findings provide important new insights into the role of the parasitic mite Varroa destructor in influencing the viral landscape that affects honeybee colonies. PMID:25144447

Vision and air flow combine to streamline flying honeybees

PubMed Central

Taylor, Gavin J.; Luu, Tien; Ball, David; Srinivasan, Mandyam V.

2013-01-01

Insects face the challenge of integrating multi-sensory information to control their flight. Here we study a ‘streamlining' response in honeybees, whereby honeybees raise their abdomen to reduce drag. We find that this response, which was recently reported to be mediated by optic flow, is also strongly modulated by the presence of air flow simulating a head wind. The Johnston's organs in the antennae were found to play a role in the measurement of the air speed that is used to control the streamlining response. The response to a combination of visual motion and wind is complex and can be explained by a model that incorporates a non-linear combination of the two stimuli. The use of visual and mechanosensory cues increases the strength of the streamlining response when the stimuli are present concurrently. We propose this multisensory integration will make the response more robust to transient disturbances in either modality. PMID:24019053

Differential antennal proteome comparison of adult honeybee drone, worker and queen (Apis mellifera L.).

PubMed

Fang, Yu; Song, Feifei; Zhang, Lan; Aleku, Dereje Woltedji; Han, Bin; Feng, Mao; Li, Jianke

2012-01-04

To understand the olfactory mechanism of honeybee antennae in detecting specific volatile compounds in the atmosphere, antennal proteome differences of drone, worker and queen were compared using 2-DE, mass spectrometry and bioinformatics. Therefore, 107 proteins were altered their expressions in the antennae of drone, worker and queen bees. There were 54, 21 and 32 up-regulated proteins in the antennae of drone, worker and queen, respectively. Proteins upregulated in the drone antennae were involved in fatty acid metabolism, antioxidation, carbohydrate metabolism and energy production, protein folding and cytoskeleton. Proteins upregulated in the antennae of worker and queen bees were related to carbohydrate metabolism and energy production while molecular transporters were upregulated in the queen antennae. Our results explain the role played by the antennae of drone is to aid in perceiving the queen sexual pheromones, in the worker antennae to assist for food search and social communication and in the queen antennae to help pheromone communication with the worker and the drone during the mating flight. This first proteomic study significantly extends our understanding of honeybee olfactory activities and the possible mechanisms played by the antennae in response to various environmental, social, biological and biochemical signals. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Changes in sulfhydryl groups of honeybee glyceraldehyde phosphate dehydrogenase associated with generation of the intermediate plateau in its saturation kinetics

NASA Technical Reports Server (NTRS)

Gelb, W. G.; Brandts, J. F.; Nordin, J. H.

1973-01-01

Honeybee and rabbit muscle GPDH were studied to obtain information at the chemical level regarding anomolous saturation kinetics of the honeybee enzyme. Results demonstrate that the enzyme's sulfhydryl groups are implicated in the process. Measured by DTNB titration, native honeybee GPDH has one less active SH than the native rabbit muscle enzyme and displays changes in overall sulfhydryl reactivity after preincubation with G-3-P or G-3-P plus NAD+. The total DTNB reactive sulfhydryls of rabbit muscle GPDH are not changed by preincubation with NAD+ or G-3-P; honeybee GPDH, under certain conductions of preincubation with these ligands, shows a decrease of two total DTNB reactive SH groups. This difference has been confirmed by an independent experiment in which the two enzymes were carboxymethylated with C-14 bromoacetic acid.

Effect of Flumethrin on Survival and Olfactory Learning in Honeybees

PubMed Central

Tan, Ken; Yang, Shuang; Wang, Zhengwei; Menzel, Randolf

2013-01-01

Flumethrin has been widely used as an acaricide for the control of Varroa mites in commercial honeybee keeping throughout the world for many years. Here we test the mortality of the Asian honeybee Apis cerana cerana after treatment with flumethrin. We also ask (1) how bees react to the odor of flumethrin, (2) whether its odor induces an innate avoidance response, (3) whether its taste transmits an aversive reinforcing component in olfactory learning, and (4) whether its odor or taste can be associated with reward in classical conditioning. Our results show that flumethrin has a negative effect on Apis ceranàs lifespan, induces an innate avoidance response, acts as a punishing reinforcer in olfactory learning, and interferes with the association of an appetitive conditioned stimulus. Furthermore flumethrin uptake within the colony reduces olfactory learning over an extended period of time. PMID:23785490

In-depth phosphoproteomic analysis of royal jelly derived from western and eastern honeybee species.

PubMed

Han, Bin; Fang, Yu; Feng, Mao; Lu, Xiaoshan; Huo, Xinmei; Meng, Lifeng; Wu, Bin; Li, Jianke

2014-12-05

The proteins in royal jelly (RJ) play a pivotal role in the nutrition, immune defense, and cast determination of honeybee larvae and have a wide range of pharmacological and health-promoting functions for humans as well. Although the importance of post-translational modifications (PTMs) in protein function is known, investigation of protein phosphorylation of RJ proteins is still very limited. To this end, two complementary phosphopeptide enrichment materials (Ti(4+)-IMAC and TiO2) and high-sensitivity mass spectrometry were applied to establish a detailed phosphoproteome map and to qualitatively and quantitatively compare the phosphoproteomes of RJ produced by Apis mellifera ligustica (Aml) and Apis cerana cerana (Acc). In total, 16 phosphoproteins carrying 67 phosphorylation sites were identified in RJ derived from western bees, and nine proteins phosphorylated on 71 sites were found in RJ produced by eastern honeybees. Of which, eight phosphorylated proteins were common to both RJ samples, and the same motif ([S-x-E]) was extracted, suggesting that the function of major RJ proteins as nutrients and immune agents is evolutionary preserved in both of these honeybee species. All eight overlapping phosphoproteins showed significantly higher abundance in Acc-RJ than in Aml-RJ, and the phosphorylation of Jelleine-II (an antimicrobial peptide, TPFKLSLHL) at S(6) in Acc-RJ had stronger antimicrobial properties than that at T(1) in Aml-RJ even though the overall antimicrobial activity of Jelleine-II was found to decrease after phosphorylation. The differences in phosphosites, peptide abundance, and antimicrobial activity of the phosphorylated RJ proteins indicate that the two major honeybee species employ distinct phosphorylation strategies that align with their different biological characteristics shaped by evolution. The phosphorylation of RJ proteins are potentially driven by the activity of extracellular serine/threonine protein kinase FAM20C-like protein (FAM20C

How regulation based on a common stomach leads to economic optimization of honeybee foraging.

PubMed

Schmickl, Thomas; Karsai, Istvan

2016-01-21

Simple regulatory mechanisms based on the idea of the saturable 'common stomach' can control the regulation of protein foraging and protein allocation in honeybee colonies and colony-level responses to environmental changes. To study the economic benefits of pollen and nectar foraging strategies of honeybees to both plants and honeybees under different environmental conditions, a model was developed and analyzed. Reallocation of the foraging workforce according to the quality and availability of resources (an 'adaptive' strategy used by honeybees) is not only a successful strategy for the bees but also for plants, because intensified pollen foraging after rain periods (when nectar quality is low) compensates a major fraction of the pollination flights lost during the rain. The 'adaptive' strategy performed better than the'fixed' (steady, minimalistic, and non-adaptive foraging without feedback) or the 'proactive' (stockpiling in anticipation of rain) strategies in brood survival and or in nectar/sugar economics. The time pattern of rain periods has profound effect on the supply-and-demand of proteins. A tropical rain pattern leads to a shortage of the influx of pollen and nectar, but it has a less profound impact on brood mortality than a typical continental rainfall pattern. Allocating more bees for pollen foraging has a detrimental effect on the nectar stores, therefore while saving larvae from starvation the 'proactive' strategy could fail to collect enough nectar for surviving winter. Copyright © 2015 Elsevier Ltd. All rights reserved.

Resilience of honeybee colonies via common stomach: A model of self-regulation of foraging

PubMed Central

Schmickl, Thomas

2017-01-01

We propose a new regulation mechanism based on the idea of the “common stomach” to explain several aspects of the resilience and homeostatic regulation of honeybee colonies. This mechanism exploits shared pools of substances (pollen, nectar, workers, brood) that modulate recruitment, abandonment and allocation patterns at the colony-level and enable bees to perform several survival strategies to cope with difficult circumstances: Lack of proteins leads to reduced feeding of young brood, to early capping of old brood and to regaining of already spent proteins through brood cannibalism. We modeled this system by linear interaction terms and mass-action law. To test the predictive power of the model of this regulatory mechanism we compared our model predictions to experimental data of several studies. These comparisons show that the proposed regulation mechanism can explain a variety of colony level behaviors. Detailed analysis of the model revealed that these mechanisms could explain the resilience, stability and self-regulation observed in honeybee colonies. We found that manipulation of material flow and applying sudden perturbations to colony stocks are quickly compensated by a resulting counter-acting shift in task selection. Selective analysis of feedback loops allowed us to discriminate the importance of different feedback loops in self-regulation of honeybee colonies. We stress that a network of simple proximate mechanisms can explain significant colony-level abilities that can also be seen as ultimate reasoning of the evolutionary trajectory of honeybees. PMID:29161278

Chemical composition and antimicrobial activity of honeybee ( Apis mellifera ligustica) propolis from subtropical eastern Australia

NASA Astrophysics Data System (ADS)

Massaro, Carmelina Flavia; Simpson, Jack Bruce; Powell, Daniel; Brooks, Peter

2015-12-01

Propolis is a material manufactured by bees and contains beeswax, bee salivary secretions and plant resins. Propolis preparations have been used for millennia by humans in food, cosmetics and medicines due to its antibacterial effects. Within the hive, propolis plays an important role in bees' health, with much of its bioactivity largely dependent on the plant resins the bees select for its production. Few chemical studies are available on the chemistry of propolis produced by Australian honeybees ( Apis mellifera, Apidae). This study aimed to determine the chemical composition as well as in vitro antimicrobial effects of propolis harvested from honeybees in subtropical eastern Australia. Honeybee propolis was produced using plastic frames and multiple beehives in two subtropical sites in eastern Australia. Methanolic extracts of propolis were analysed by liquid chromatography with ultraviolet detection and high-resolution mass spectrometry (ultra-high-pressure liquid chromatography (UHPLC)-UV-high-resolution tandem mass spectrometry (HR-MS/MS)) and by gas chromatography mass spectrometry (GC-MS). The resulting chemical data were dereplicated for compound characterisation. The two crude extracts in abs. ethanol were tested in vitro by the agar diffusion and broth dilution methods, using a phenol standard solution as the positive control and abs. ethanol as the negative control. Chemical constituents were identified to be pentacyclic triterpenoids and C-prenylated flavonoids, including Abyssinoflavanone VII, Propolin C and Nymphaeol C. The two propolis crude extracts showed bactericidal effects at the minimal inhibitory concentrations of 0.37-2.04 mg mL-1 against Staphylococcus aureus ATCC 25923. However, the extracts were inactive against Klebsiella pneumoniae ATCC 13883 and Candida albicans ATCC 10231. The antistaphylococcal potential of propolis was discussed, also in relation to honeybees' health, as it warrants further investigations on the social and

Chemical composition and antimicrobial activity of honeybee (Apis mellifera ligustica) propolis from subtropical eastern Australia.

PubMed

Massaro, Carmelina Flavia; Simpson, Jack Bruce; Powell, Daniel; Brooks, Peter

2015-12-01

Propolis is a material manufactured by bees and contains beeswax, bee salivary secretions and plant resins. Propolis preparations have been used for millennia by humans in food, cosmetics and medicines due to its antibacterial effects. Within the hive, propolis plays an important role in bees' health, with much of its bioactivity largely dependent on the plant resins the bees select for its production. Few chemical studies are available on the chemistry of propolis produced by Australian honeybees (Apis mellifera, Apidae). This study aimed to determine the chemical composition as well as in vitro antimicrobial effects of propolis harvested from honeybees in subtropical eastern Australia. Honeybee propolis was produced using plastic frames and multiple beehives in two subtropical sites in eastern Australia. Methanolic extracts of propolis were analysed by liquid chromatography with ultraviolet detection and high-resolution mass spectrometry (ultra-high-pressure liquid chromatography (UHPLC)-UV-high-resolution tandem mass spectrometry (HR-MS/MS)) and by gas chromatography mass spectrometry (GC-MS). The resulting chemical data were dereplicated for compound characterisation. The two crude extracts in abs. ethanol were tested in vitro by the agar diffusion and broth dilution methods, using a phenol standard solution as the positive control and abs. ethanol as the negative control. Chemical constituents were identified to be pentacyclic triterpenoids and C-prenylated flavonoids, including Abyssinoflavanone VII, Propolin C and Nymphaeol C. The two propolis crude extracts showed bactericidal effects at the minimal inhibitory concentrations of 0.37-2.04 mg mL(-1) against Staphylococcus aureus ATCC 25923. However, the extracts were inactive against Klebsiella pneumoniae ATCC 13883 and Candida albicans ATCC 10231. The antistaphylococcal potential of propolis was discussed, also in relation to honeybees' health, as it warrants further investigations on the social and

Forward and Backward Second-Order Pavlovian Conditioning in Honeybees

ERIC Educational Resources Information Center

Hussaini, Syed Abid; Komischke, Bernhard; Menzel, Randolf; Lachnit, Harald

2007-01-01

Second-order conditioning (SOC) is the association of a neutral stimulus with another stimulus that had previously been combined with an unconditioned stimulus (US). We used classical conditioning of the proboscis extension response (PER) in honeybees ("Apis mellifera") with odors (CS) and sugar (US). Previous SOC experiments in bees were…

Ethanol self-administration in free-flying honeybees (Apis mellifera L.) in an operant conditioning protocol.

PubMed

Sokolowski, Michel B C; Abramson, Charles I; Craig, David Philip Arthur

2012-09-01

This study examines the effect of ethanol (EtOH) on continuous reinforcement schedules in the free-flying honeybee (Apis mellifera L.). As fermented nectars may be encountered naturally in the environment, we designed an experiment combining the tools of laboratory research with minimal disturbance to the natural life of honeybees. Twenty-five honeybees were trained to fly from their colonies to a fully automated operant chamber with head poking as the operant response. Load size, intervisit interval, and interresponse times (IRTs) served as the dependent variables and were monitored over the course of a daily training session consisting of many visits. Experimental bees were tested using an ABA design in which sucrose only was administered during condition A and a 5% EtOH sucrose solution was administered during condition B. Control bees received sucrose solution only. Most bees continued to forage after EtOH introduction. EtOH significantly reduced the load size and the intervisit interval with no significant effect on IRTs. However, a look on individual data shows large individual differences suggesting the existence of different kinds of behavioral phenotypes linked to EtOH consumption and effects. Our results contribute to the study of EtOH consumption as a normal phenomenon in an ecological context and open the door to schedule-controlled drug self-administration studies in honeybees. Copyright © 2012 by the Research Society on Alcoholism.

Localization of deformed wing virus (DWV) in the brains of the honeybee, Apis mellifera Linnaeus.

PubMed

Shah, Karan S; Evans, Elizabeth C; Pizzorno, Marie C

2009-10-30

Deformed wing virus (DWV) is a positive-strand RNA virus that infects European honeybees (Apis mellifera L.) and has been isolated from the brains of aggressive bees in Japan. DWV is known to be transmitted both vertically and horizontally between bees in a colony and can lead to both symptomatic and asymptomatic infections in bees. In environmentally stressful conditions, DWV can contribute to the demise of a honeybee colony. The purpose of the current study is to identify regions within the brains of honeybees where DWV replicates using in-situ hybridization. In-situ hybridizations were conducted with both sense and antisense probes on the brains of honeybees that were positive for DWV as measured by real-time RT-PCR. The visual neuropils demonstrated detectable levels of the DWV positive-strand genome. The mushroom bodies and antenna lobe neuropils also showed the presence of the viral genome. Weaker staining with the sense probe in the same regions demonstrates that the antigenome is also present and that the virus is actively replicating in these regions of the brain. These results demonstrate that in bees infected with DWV the virus is replicating in critical regions of the brain, including the neuropils responsible for vision and olfaction. Therefore DWV infection of the brain could adversely affect critical sensory functions and alter normal bee behavior.

EPIDEMIOLOGY OF HONEYBEE STING CASES IN THE STATE OF CEARÁ, NORTHEASTERN BRAZIL.

PubMed

Diniz, Ana Gilza Quaresma; Belmino, José Franscidavid Barbosa; Araújo, Kaliany Adja Medeiros de; Vieira, Aluska Tavares; Leite, Renner de Souza

2016-01-01

In the American continent, honeybee envenomation is a public health problem due to the high incidence and severity of the cases. Despite its medical importance, there is a lack of epidemiological studies on this topic in Brazil, especially referring to the Northeastern states. The present study has aimed to describe the epidemiological features of honeybee envenomation cases in the state of the Ceará, Northeastern Brazil, from 2007 to 2013. Data were collected from the Injury Notification Information System database of the Health Department of Ceará. A total of 1,307 cases were analyzed. Cases were shown to be distributed in all the months of the studied years, reaching higher frequencies in August. The majority of cases occurred in urban areas and involved men aged between 20 and 29 years. Victims were mainly stung on the head and torso, and they received medical assistance predominantly within 3 hours after being stung. Local manifestations were more frequent than systemic ones. Most cases were classified as mild and progressed to cure. The high number of honeybee sting cases shows that Ceará may be an important risk area for such injuries. Moreover, the current study provides data for the development of strategies to promote control and prevention of bee stings in this area.

The endangered Iris atropurpurea (Iridaceae) in Israel: honey-bees, night-sheltering male bees and female solitary bees as pollinators

PubMed Central

Watts, Stella; Sapir, Yuval; Segal, Bosmat; Dafni, Amots

2013-01-01

Background and Aims The coastal plain of Israel hosts the last few remaining populations of the endemic Iris atropurpurea (Iridaceae), a Red List species of high conservation priority. The flowers offer no nectar reward. Here the role of night-sheltering male solitary bees, honey-bees and female solitary bees as pollinators of I. atropurpurea is documented. Methods Breeding system, floral longevity, stigma receptivity, visitation rates, pollen loads, pollen deposition and removal and fruit- and seed-set were investigated. Key Results The main wild pollinators of this plant are male eucerine bees, and to a lesser extent, but with the potential to transfer pollen, female solitary bees. Honey-bees were found to be frequent diurnal visitors; they removed large quantities of pollen and were as effective as male sheltering bees at pollinating this species. The low density of pollen carried by male solitary bees was attributed to grooming activities, pollen displacement when bees aggregated together in flowers and pollen depletion by honey-bees. In the population free of honey-bee hives, male bees carried significantly more pollen grains on their bodies. Results from pollen analysis and pollen deposited on stigmas suggest that inadequate pollination may be an important factor limiting fruit-set. In the presence of honey-bees, eucerine bees were low removal–low deposition pollinators, whereas honey-bees were high removal–low deposition pollinators, because they removed large amounts into corbiculae and deposited relatively little onto receptive stigmas. Conclusions Even though overall, both bee taxa were equally effective pollinators, we suggest that honey-bees have the potential to reduce the amount of pollen available for plant reproduction, and to reduce the amount of resources available to solitary bee communities. The results of this study have potential implications for the conservation of this highly endangered plant species if hives are permitted inside

Individual recognition and learning of queen odors by worker honeybees

PubMed Central

Breed, Michael D.

1981-01-01

A honeybee queen is usually attacked if she is placed among the workers of a colony other than her own. This rejection occurs even if environmental sources of odor, such as food, water, and genetic origin of the workers, are kept constant in laboratory conditions. The genetic similarity of queens determines how similar their recognition characteristics are; inbred sister queens were accepted in 35% of exchanges, outbred sister queens in 12%, and nonsister queens in 0%. Carbon dioxide narcosis results in worker honeybees accepting nonnestmate queens. A learning curve is presented, showing the time after narcosis required by workers to learn to recognize a new queen. In contrast, worker transfers result in only a small percentage of the workers being rejected. The reason for the difference between queens and workers may be because of worker and queen recognition cues having different sources. PMID:16593008

Effect of lyophilized powder made from enzymolyzed honeybee larvae on tinnitus-related symptoms, hearing levels, and hypothalamus-pituitary-adrenal axis-related hormones.

PubMed

Aoki, Mitsuhiro; Wakaoka, Yoshinori; Hayashi, Hisamitsu; Kuze, Bunya; Mizuta, Keisuke; Ito, Yatsuji

2012-01-01

Tinnitus interferes with sleep and concentration which is associated with depression; however, no drug has been effective in treating tinnitus. Our purpose is to evaluate our hypothesis that the treatment with lyophilized powder of enzymolyzed honeybee larvae as a complementary medicine may provide a therapeutic effect on tinnitus-related symptoms. Sixty tinnitus sufferers participated in a randomized double-blind placebo-controlled trial using the lyophilized powder of enzymolyzed honeybee larvae or a placebo. The Tinnitus Handicap Inventory, a visual analog scale to rate the severity of tinnitus, hearing levels, and hypothalamus-pituitary-adrenal axis-related hormones drawn early in the morning were measured upon entry into the study and after 12 wk of follow-up. The lyophilized powder of enzymolyzed honeybee larvae was not superior to placebo with regard to the total score on the Tinnitus Handicap Inventory and the visual analog scale. However, subjects in the honeybee larvae group showed significant improvements in some items about depression associated with tinnitus, whereas subjects in the placebo group showed no improvement in any items. The honeybee larvae group showed significant improvements in the hearing levels at 2 and 4 kHz in the audiogram of the better ear. The intervention of the lyophilized powder of enzymolyzed honeybee larvae was associated with lower serum cortisol levels, serum prolactin levels, and cortisol/dehydroepiandrosterone sulfate ratios. The ratios in the placebo group significantly were increased. Our results suggest that the lyophilized powder of enzymolyzed honeybee larvae represents an effective complementary medicine to alleviate depression associated with tinnitus by regulating the activity of the hypothalamus-pituitary-adrenal axis.

Comparative study on the dynamics and performances of Apis mellifera jemenitica and imported hybrid honeybee colonies in southwestern Saudi Arabia.

PubMed

Al-Ghamdi, Ahmad A; Adgaba, Nuru; Tadesse, Yilma; Getachew, Awraris; Al-Maktary, Anwer A

2017-07-01

The aims of this study were to assess the seasonal population dynamics and evaluate the performance of Apis mellifera jemenitica (local bee) and introduced hybrid honeybee colonies in the lowlands and highlands of southwestern Saudi Arabia. Data regarding the performance and population dynamics parameters such as brood and adult bee population, amounts of stored pollen and nectar were gathered from the two races (25 colonies of each) for one year (April 2013 through March 2014), and statistically tested. The results indicated that at low lands, local bee colonies maintained relatively high brood and adult bee populations ( P  < 0.05) than introduced honeybee colonies and produced more ( P  < 0.05) honey. The local bee colonies were able to hoard three times more ( P  < 0.05) pollen and built more ( P  < 0.05) queen cells than introduced bees in both the low and highland areas. The annual survival rate of local bee colonies was almost double ( P  < 0.05) than that of introduced honeybee colonies. Moreover, local bees had greater ( P  < 0.05) adult bee and brood populations than imported, throughout the year. The relatively good performance of local colonies could be due to their long year's adaptation to cope with resource scarcity and unpredictable environmental conditions of the regions. The possible reasons for the dwindling of the imported hybrid colonies could be due to continuing to exhibit adaptive characteristics of their original that might not fit well with the new environment.

Caffeinated forage tricks honeybees into increasing foraging and recruitment behaviors.

PubMed

Couvillon, Margaret J; Al Toufailia, Hasan; Butterfield, Thomas M; Schrell, Felix; Ratnieks, Francis L W; Schürch, Roger

2015-11-02

In pollination, plants provide food reward to pollinators who in turn enhance plant reproduction by transferring pollen, making the relationship largely cooperative; however, because the interests of plants and pollinators do not always align, there exists the potential for conflict, where it may benefit both to cheat the other [1, 2]. Plants may even resort to chemistry: caffeine, a naturally occurring, bitter-tasting, pharmacologically active secondary compound whose main purpose is to detract herbivores, is also found in lower concentrations in the nectar of some plants, even though nectar, unlike leaves, is made to be consumed by pollinators. [corrected]. A recent laboratory study showed that caffeine may lead to efficient and effective foraging by aiding honeybee memory of a learned olfactory association [4], suggesting that caffeine may enhance bee reward perception. However, without field data, the wider ecological significance of caffeinated nectar remains difficult to interpret. Here we demonstrate in the field that caffeine generates significant individual- and colony-level effects in free-flying worker honeybees. Compared to a control, a sucrose solution with field-realistic doses of caffeine caused honeybees to significantly increase their foraging frequency, waggle dancing probability and frequency, and persistency and specificity to the forage location, resulting in a quadrupling of colony-level recruitment. An agent-based model also demonstrates how caffeine-enhanced foraging may reduce honey storage. Overall, caffeine causes bees to overestimate forage quality, tempting the colony into sub-optimal foraging strategies, which makes the relationship between pollinator and plant less mutualistic and more exploitative. VIDEO ABSTRACT. Copyright © 2015 Elsevier Ltd. All rights reserved.

A fifth major genetic group among honeybees revealed in Syria

PubMed Central

2013-01-01

Background Apiculture has been practiced in North Africa and the Middle-East from antiquity. Several thousand years of selective breeding have left a mosaic of Apis mellifera subspecies in the Middle-East, many uniquely adapted and survived to local environmental conditions. In this study we explore the genetic diversity of A. mellifera from Syria (n = 1258), Lebanon (n = 169) and Iraq (n = 35) based on 14 short tandem repeat (STR) loci in the context of reference populations from throughout the Old World (n = 732). Results Our data suggest that the Syrian honeybee Apis mellifera syriaca occurs in both Syrian and Lebanese territories, with no significant genetic variability between respective populations from Syria and Lebanon. All studied populations clustered within a new fifth independent nuclear cluster, congruent with an mtDNA Z haplotype identified in a previous study. Syrian honeybee populations are not associated with Oriental lineage O, except for sporadic introgression into some populations close to the Turkish and Iraqi borders. Southern Syrian and Lebanese populations demonstrated high levels of genetic diversity compared to the northern populations. Conclusion This study revealed the effects of foreign queen importations on Syrian bee populations, especially for the region of Tartus, where extensive introgression of A. m. anatolica and/or A. m. caucasica alleles were identified. The policy of creating genetic conservation centers for the Syrian subspecies should take into consideration the influence of the oriental lineage O from the northern Syrian border and the large population of genetically divergent indigenous honeybees located in southern Syria. PMID:24314104

A fifth major genetic group among honeybees revealed in Syria.

PubMed

Alburaki, Mohamed; Bertrand, Bénédicte; Legout, Hélène; Moulin, Sibyle; Alburaki, Ali; Sheppard, Walter Steven; Garnery, Lionel

2013-12-06

Apiculture has been practiced in North Africa and the Middle-East from antiquity. Several thousand years of selective breeding have left a mosaic of Apis mellifera subspecies in the Middle-East, many uniquely adapted and survived to local environmental conditions. In this study we explore the genetic diversity of A. mellifera from Syria (n = 1258), Lebanon (n = 169) and Iraq (n = 35) based on 14 short tandem repeat (STR) loci in the context of reference populations from throughout the Old World (n = 732). Our data suggest that the Syrian honeybee Apis mellifera syriaca occurs in both Syrian and Lebanese territories, with no significant genetic variability between respective populations from Syria and Lebanon. All studied populations clustered within a new fifth independent nuclear cluster, congruent with an mtDNA Z haplotype identified in a previous study. Syrian honeybee populations are not associated with Oriental lineage O, except for sporadic introgression into some populations close to the Turkish and Iraqi borders. Southern Syrian and Lebanese populations demonstrated high levels of genetic diversity compared to the northern populations. This study revealed the effects of foreign queen importations on Syrian bee populations, especially for the region of Tartus, where extensive introgression of A. m. anatolica and/or A. m. caucasica alleles were identified. The policy of creating genetic conservation centers for the Syrian subspecies should take into consideration the influence of the oriental lineage O from the northern Syrian border and the large population of genetically divergent indigenous honeybees located in southern Syria.

Genetic diversity of the Dwarf honeybee (Apis florea Fabricius, 1787) populations based on microsatellite markers.

PubMed

Asadi, N; Rahimi, A; Ghaheri, M; Kahrizi, D; Bagheri Dehbaghi, M; Khederzadeh, S; Banabazi, M H; Esmaeilkhanian, S; Veisi, B; Geravandi, M; Karim, H; Vaziri, S; Daneshgar, F; Zargooshi, J

2016-10-31

Apis florea is one of two species of small, wild honeybee. The present study was conducted to evaluate the genetic diversity of Apis florea honeybee from 48 nests (colonies) using microsatellite markers in the South of Iran. All honeybee samples were analyzed for six microsatellite loci (A88, A107, A7, B124, A113 and A35). The six loci had different numbers of alleles in the sampled colonies ranging from 7 (loci A107) to 3 (loci A7, A35). Gene diversity in Apis florea ranged from 0.491 to 0.595. This range probably reflects the spreading of nests in a large region with a varied climate. Phylogenetic tree showed two distinct clusters including a) Minab region samples and b) Bandar Abbas, Bandar Khamir and Qeshm Island regions. All of these regions are geographically rich, having varied vegetation and climate conditions. Our findings are an important contribution to the methods of studying distribution and conservation of Apis florea.

Proteinase pattern of honeybee prepupae from healthy and American Foulbrood infected bees investigated by zymography.

PubMed

Felicioli, Antonio; Turchi, Barbara; Fratini, Filippo; Giusti, Matteo; Nuvoloni, Roberta; Dani, Francesca Romana; Sagona, Simona

2018-05-15

American foulbrood disease (AFB) is the main devastating disease that affects honeybees' brood, caused by Paenibacillus larvae. The trend of the research on AFB has addressed the mechanisms by which P. larvae bacteria kill honeybee larvae. Since prepupae could react to the infection of AFB by increasing protease synthesis, the aim of this work was to compare protease activity in worker prepupae belonging to healthy colonies and to colonies affected by AFB. This investigation was performed by zymography. In gel, proteolytic activity was observed in prepupae extracts belonging only to the healthy colonies. In the prepupae extracts, 2D zimography followed by protein identification by MS allowed to detect Trypsin-1 and Chymotrypsin-1, which were not observed in diseased specimens. Further investigations are needed to clarify the involvement of these proteinases in the immune response of honeybee larvae and the mechanisms by which P. larvae inhibits protease production in its host. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification of Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus fermentum from honey stomach of honeybee

PubMed Central

Tajabadi, Naser; Mardan, Makhdzir; Saari, Nazamid; Mustafa, Shuhaimi; Bahreini, Rasoul; Manap, Mohd Yazid Abdul

2013-01-01

This study aimed to isolate and identify Lactobacillus in the honey stomach of honeybee Apis dorsata. Samples of honeybee were collected from A. dorsata colonies in different bee trees and Lactobacillus bacteria isolated from honey stomachs. Ninety two isolates were Gram-stained and tested for catalase reaction. By using bacterial universal primers, the 16S rDNA gene from DNA of bacterial colonies amplified with polymerase chain reaction (PCR). Forty-nine bacterial 16S rDNA gene were sequenced and entrusted in GenBank. Phylogenetic analysis showed they were different phylotypes of Lactobacillus. Two of them were most closely relevant to the previously described species Lactobacillus plantarum. Other two phylotypes were identified to be closely related to Lactobacillus pentosus. However, only one phylotype was found to be distantly linked to the Lactobacillus fermentum. The outcomes of the present study indicated that L. plantarum, L. pentosus, and L. fermentum were the dominant lactobacilli in the honey stomach of honeybee A. dorsata collected during the dry season from Malaysia forest area - specifically “Melaleuca in Terengganu”. PMID:24516438

Identification of Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus fermentum from honey stomach of honeybee.

PubMed

Tajabadi, Naser; Mardan, Makhdzir; Saari, Nazamid; Mustafa, Shuhaimi; Bahreini, Rasoul; Manap, Mohd Yazid Abdul

2013-01-01

This study aimed to isolate and identify Lactobacillus in the honey stomach of honeybee Apis dorsata. Samples of honeybee were collected from A. dorsata colonies in different bee trees and Lactobacillus bacteria isolated from honey stomachs. Ninety two isolates were Gram-stained and tested for catalase reaction. By using bacterial universal primers, the 16S rDNA gene from DNA of bacterial colonies amplified with polymerase chain reaction (PCR). Forty-nine bacterial 16S rDNA gene were sequenced and entrusted in GenBank. Phylogenetic analysis showed they were different phylotypes of Lactobacillus. Two of them were most closely relevant to the previously described species Lactobacillus plantarum. Other two phylotypes were identified to be closely related to Lactobacillus pentosus. However, only one phylotype was found to be distantly linked to the Lactobacillus fermentum. The outcomes of the present study indicated that L. plantarum, L. pentosus, and L. fermentum were the dominant lactobacilli in the honey stomach of honeybee A. dorsata collected during the dry season from Malaysia forest area - specifically "Melaleuca in Terengganu".

The Bacterium Frischella perrara Causes Scab Formation in the Gut of its Honeybee Host

PubMed Central

Bartlett, Kelsey D.; Moran, Nancy A.

2015-01-01

ABSTRACT Honeybees harbor well-defined bacterial communities in their guts. The major members of these communities appear to benefit the host, but little is known about how they interact with the host and specifically how they interface with the host immune system. In the pylorus, a short region between the midgut and hindgut, honeybees frequently exhibit scab-like structures on the epithelial gut surface. These structures are reminiscent of a melanization response of the insect immune system. Despite the wide distribution of this phenotype in honeybee populations, its cause has remained elusive. Here, we show that the presence of a common member of the bee gut microbiota, the gammaproteobacterium Frischella perrara, correlates with the appearance of the scab phenotype. Bacterial colonization precedes scab formation, and F. perrara specifically localizes to the melanized regions of the host epithelium. Under controlled laboratory conditions, we demonstrate that exposure of microbiota-free bees to F. perrara but not to other bacteria results in scab formation. This shows that F. perrara can become established in a spatially restricted niche in the gut and triggers a morphological change of the epithelial surface, potentially due to a host immune response. As an intermittent colonizer, this bacterium holds promise for addressing questions of community invasion in a simple yet relevant model system. Moreover, our results show that gut symbionts of bees engage in differential host interactions that are likely to affect gut homeostasis. Future studies should focus on how these different gut bacteria impact honeybee health. PMID:25991680

Brood comb as a humidity buffer in honeybee nests

NASA Astrophysics Data System (ADS)

Ellis, Michael B.; Nicolson, Sue W.; Crewe, Robin M.; Dietemann, Vincent

2010-04-01

Adverse environmental conditions can be evaded, tolerated or modified in order for an organism to survive. During their development, some insect larvae spin cocoons which, in addition to protecting their occupants against predators, modify microclimatic conditions, thus facilitating thermoregulation or reducing evaporative water loss. Silk cocoons are spun by honeybee ( Apis mellifera) larvae and subsequently incorporated into the cell walls of the wax combs in which they develop. The accumulation of this hygroscopic silk in the thousands of cells used for brood rearing may significantly affect nest homeostasis by buffering humidity fluctuations. This study investigates the extent to which the comb may influence homeostasis by quantifying the hygroscopic capacity of the cocoons spun by honeybee larvae. When comb containing cocoons was placed at high humidity, it absorbed 11% of its own mass in water within 4 days. Newly drawn comb composed of hydrophobic wax and devoid of cocoons absorbed only 3% of its own mass. Therefore, the accumulation of cocoons in the comb may increase brood survivorship by maintaining a high and stable humidity in the cells.

Context odor presentation during sleep enhances memory in honeybees.

PubMed

Zwaka, Hanna; Bartels, Ruth; Gora, Jacob; Franck, Vivien; Culo, Ana; Götsch, Moritz; Menzel, Randolf

2015-11-02

Sleep plays an important role in stabilizing new memory traces after learning [1-3]. Here we investigate whether sleep's role in memory processing is similar in evolutionarily distant species and demonstrate that a context trigger during deep-sleep phases improves memory in invertebrates, as it does in humans. We show that in honeybees (Apis mellifera), exposure to an odor during deep sleep that has been present during learning improves memory performance the following day. Presentation of the context odor during wake phases or novel odors during sleep does not enhance memory. In humans, memory consolidation can be triggered by presentation of a context odor during slow-wave sleep that had been present during learning [3-5]. Our results reveal that deep-sleep phases in honeybees have the potential to prompt memory consolidation, just as they do in humans. This study provides strong evidence for a conserved role of sleep-and how it affects memory processes-from insects to mammals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sensing the intruder: a quantitative threshold for recognition cues perception in honeybees

NASA Astrophysics Data System (ADS)

Cappa, Federico; Bruschini, Claudia; Cipollini, Maria; Pieraccini, Giuseppe; Cervo, Rita

2014-02-01

The ability to discriminate among nestmates and non-nestmate is essential to defend social insect colonies from intruders. Over the years, nestmate recognition has been extensively studied in the honeybee Apis mellifera; nevertheless, the quantitative perceptual aspects at the basis of the recognition system represent an unexplored subject in this species. To test the existence of a cuticular hydrocarbons' quantitative perception threshold for nestmate recognition cues, we conducted behavioural assays by presenting different amounts of a foreign forager's chemical profile to honeybees at the entrance of their colonies. We found an increase in the explorative and aggressive responses as the amount of cues increased based on a threshold mechanism, highlighting the importance of the quantitative perceptual features for the recognition processes in A. mellifera.

Monitoring honeybee venom immunotherapy in children with the basophil activation test.

PubMed

Žitnik, Simona E K; Vesel, Tina; Avčin, Tadej; Šilar, Mira; Košnik, Mitja; Korošec, Peter

2012-03-01

New in vitro methods are essential for developing better follow-up criteria for venom immunotherapy (VIT). Thirty-one children with a history of honeybee venom-induced systemic anaphylaxis were included in this prospective, single-blinded study. The basophil CD63 activation test (BAT) was assessed before starting VIT, at the end of the build-up phase (day 5), 6 months later, and after 2-4 yr of VIT. Basophil CD63 activation test allowed identification of the culprit insect in 74% of honeybee venom-allergic children. In comparison, IgE reactivity was single positive in only 52% of children. Five days after starting VIT, BAT was highly comparable to before VIT. However, after 6 months and further after 2-4 yr of VIT, a significant and approximately fourfold decrease was demonstrated in CD63 response at sub-maximal 0.1 μg/ml allergen concentration, which mainly represents cellular sensitivity. No such differences were found at a higher 1 μg/ml of allergen concentration. Person-to-person analyses showed that after 2-4 yr of VIT, a marked CD63 decrease was evident in 85% of children. In addition, elevated basophil sensitivity measured before VIT was associated with the appearance of side effects observed during the build-up phase of VIT. Basophil CD63 allergen-specific sensitivity seems to be a promising tool for monitoring protective immune response in honeybee VIT. © 2011 John Wiley & Sons A/S.

Honeybees and honey as monitors for heavy metal contamination near thermal power plants in Mugla, Turkey.

PubMed

Silici, Sibel; Uluozlu, Ozgur Dogan; Tuzen, Mustafa; Soylak, Mustafa

2016-03-01

In the present work, 6 honeydew samples of known geographical and botanical origins and 11 honeybee samples were analyzed to detect possible contamination by the thermoelectric power plants in Mugla, Turkey. The contents of trace elements were determined by atomic absorption spectrometry after application of microwave digestion. The samples from the thermal power plants, which were 10-22 km away from the hives, that did not cause pollution in honeydew honeys were also analyzed. The levels of copper, cadmium (Cd), lead (Pb), zinc, manganese, iron, chromium, nickel, and aluminum were similar to the values found in other recent studies in literature. However, it was found that the contamination levels of the toxic elements such as Pb and Cd in honeybee samples measured relatively higher than that of honey samples. The study concludes that honeybees may be better bioindicators of heavy metal pollution than honey. © The Author(s) 2013.

Chemical Composition of Different Botanical Origin Honeys Produced by Sicilian Black Honeybees (Apis mellifera ssp. sicula).

PubMed

Mannina, Luisa; Sobolev, Anatoly P; Di Lorenzo, Arianna; Vista, Silvia; Tenore, Gian Carlo; Daglia, Maria

2015-07-01

In 2008 a Slow Food Presidium was launched in Sicily (Italy) for an early warning of the risk of extinction of the Sicilian native breed of black honeybee (Apis mellifera L. ssp sicula). Today, the honey produced by these honeybees is the only Sicilian honey produced entirely by the black honeybees. In view of few available data regarding the chemical composition of A. mellifera ssp. sicula honeys, in the present investigation the chemical compositions of sulla honey (Hedysarum coronarium L.) and dill honey (Anethum graveolens L.) were studied with a multimethodological approach, which consists of HPLC-PDA-ESI-MSn and NMR spectroscopy. Moreover, three unifloral honeys (lemon honey (obtained from Citrus limon (L.) Osbeck), orange honey (Citrus arantium L.), and medlar honey (Eriobotrya japonica (Thunb.) Lindl)), with known phenol and polyphenol compositions, were studied with NMR spectroscopy to deepen the knowledge about sugar and amino acid compositions.

Extreme Recombination Frequencies Shape Genome Variation and Evolution in the Honeybee, Apis mellifera

PubMed Central

Wallberg, Andreas; Glémin, Sylvain; Webster, Matthew T.

2015-01-01

Meiotic recombination is a fundamental cellular process, with important consequences for evolution and genome integrity. However, we know little about how recombination rates vary across the genomes of most species and the molecular and evolutionary determinants of this variation. The honeybee, Apis mellifera, has extremely high rates of meiotic recombination, although the evolutionary causes and consequences of this are unclear. Here we use patterns of linkage disequilibrium in whole genome resequencing data from 30 diploid honeybees to construct a fine-scale map of rates of crossing over in the genome. We find that, in contrast to vertebrate genomes, the recombination landscape is not strongly punctate. Crossover rates strongly correlate with levels of genetic variation, but not divergence, which indicates a pervasive impact of selection on the genome. Germ-line methylated genes have reduced crossover rate, which could indicate a role of methylation in suppressing recombination. Controlling for the effects of methylation, we do not infer a strong association between gene expression patterns and recombination. The site frequency spectrum is strongly skewed from neutral expectations in honeybees: rare variants are dominated by AT-biased mutations, whereas GC-biased mutations are found at higher frequencies, indicative of a major influence of GC-biased gene conversion (gBGC), which we infer to generate an allele fixation bias 5 – 50 times the genomic average estimated in humans. We uncover further evidence that this repair bias specifically affects transitions and favours fixation of CpG sites. Recombination, via gBGC, therefore appears to have profound consequences on genome evolution in honeybees and interferes with the process of natural selection. These findings have important implications for our understanding of the forces driving molecular evolution. PMID:25902173

Longevity and food consumption of microwave-treated (2. 45 GHz CW) honeybees in the laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Westerdahl, B.B.; Gary, N.E.

1981-01-01

Adult honeybees, confined singly or in small clusters, were exposed for 0.5, 6, and 24 hours to 2.45-GHz continuous wave microwave radiation at power densities of 3, 6, 12, 25, and 50 mW/cm2. Following exposure, bees were held in the incubator for 21 days to determine the consumption of sucrose syrup and to observe mortality. No significant differences were found between microwave-treated and sham-treated or control bees.

Seminal fluid of honeybees contains multiple mechanisms to combat infections of the sexually transmitted pathogen Nosema apis.

PubMed

Peng, Yan; Grassl, Julia; Millar, A Harvey; Baer, Boris

2016-01-27

The societies of ants, bees and wasps are genetically closed systems where queens only mate during a brief mating episode prior to their eusocial life and males therefore provide queens with a lifetime supply of high-quality sperm. These ejaculates also contain a number of defence proteins that have been detected in the seminal fluid but their function and efficiency have never been investigated in great detail. Here, we used the honeybee Apis mellifera and quantified whether seminal fluid is able to combat infections of the fungal pathogen Nosema apis, a widespread honeybee parasite that is also sexually transmitted. We provide the first empirical evidence that seminal fluid has a remarkable antimicrobial activity against N. apis spores and that antimicrobial seminal fluid components kill spores in multiple ways. The protein fraction of seminal fluid induces extracellular spore germination, which disrupts the life cycle of N. apis, whereas the non-protein fraction of seminal fluid induces a direct viability loss of intact spores. We conclude that males provide their ejaculates with efficient antimicrobial molecules that are able to kill N. apis spores and thereby reduce the risk of disease transmission during mating. Our findings could be of broader significance to master honeybee diseases in managed honeybee stock in the future. © 2016 The Author(s).

Proteome Analysis of the Hemolymph, Mushroom Body, and Antenna Provides Novel Insight into Honeybee Resistance against Varroa Infestation.

PubMed

Hu, Han; Bienefeld, Kaspar; Wegener, Jakob; Zautke, Fred; Hao, Yue; Feng, Mao; Han, Bin; Fang, Yu; Wubie, Abebe Jenberie; Li, Jianke

2016-08-05

Varroa destructor has been identified as a major culprit responsible for the losses of millions of honeybee colonies. Varroa sensitive hygiene (VSH) is a suite of behaviors from adult bees to suppress mite reproduction by uncapping and/or removing mite infested pupae from a sealed brood. Despite the efforts to elucidate the molecular underpinnings of VSH, they remain largely unknown. We investigated the proteome of mushroom bodies (MBs) and antennae of adult bees with and without VSH from a stock selected for VSH based on their response to artificially Varroa-infected brood cells by near-infrared camera observation. The pupal hemolymph proteome was also compared between the VSH-line and the line that was not selected for VSH. The identified 8609 proteins in the hemolymph, MBs, and antennae represent the most depth coverage of the honeybee proteome (>55%) to date. In the hemolymph, the VSH-line adapts a unique strategy to boost the social immunity and drive pupal organogenesis by enhancing energy metabolism and protein biosynthesis. In MBs, the up-regulated proteins implicated in neuronal sensitivity suggest their roles to promote the execution of VSH by activation of synaptic vesicles and calcium channel activities. In antennae, the highly expressed proteins associated with sensitivity of olfactory senses and signal transmissions signify their roles by inputting a strong signal to the MBs for initiating VSH. These observations illustrate that the enhanced social immunities and olfactory and neuronal sensitivity play key roles in the combat against Varroa infestation. The identified candidate markers may be useful for accelerating marker-associated selection for VSH to aid in resistance to a parasite responsible for decline in honeybee health.

Obstacle traversal and route choice in flying honeybees: Evidence for individual handedness

PubMed Central

Ong, Marielle; Bulmer, Michael; Groening, Julia

2017-01-01

Flying insects constantly face the challenge of choosing efficient, safe and collision-free routes while navigating through dense foliage. We examined the route-choice behavior of foraging honeybees when they encountered a barrier which could be traversed by flying through one of two apertures, positioned side by side. When the bees’ choice behavior was averaged over the entire tested population, the two apertures were chosen with equal frequency when they were equally wide. When the apertures were of different width, the bees, on average, showed a preference for the wider aperture, which increased sharply with the difference between the aperture widths. Thus, bees are able to discriminate the widths of oncoming gaps and choose the passage which is presumably safer and quicker to transit. Examination of the behavior of individual bees revealed that, when the two apertures were equally wide, ca. 55% of the bees displayed no side bias in their choices. However, the remaining 45% showed varying degrees of bias, with one half of them preferring the left-hand aperture, and the other half the right-hand aperture. The existence of distinct individual biases was confirmed by measuring the times required by biased bees to transit various aperture configurations: The transit time was longer if a bee’s intrinsic bias forced it to engage with the narrower aperture. Our results show that, at the population level, bees do not exhibit ‘handedness’ in choosing routes; however, individual bees display an idiosyncratic bias that can range from a strong left bias, through zero bias, to a strong right bias. In honeybees, previous studies of olfactory and visual learning have demonstrated clear biases at the population level. To our knowledge, our study is the first to uncover the existence of individually distinct biases in honeybees. We also show how a distribution of biases among individual honeybees can be advantageous in facilitating rapid transit of a group of bees

Color Difference and Memory Recall in Free-Flying Honeybees: Forget the Hard Problem

PubMed Central

Dyer, Adrian G.; Garcia, Jair E.

2014-01-01

Free-flying honeybees acquire color information differently depending upon whether a target color is learnt in isolation (absolute conditioning), or in relation to a perceptually similar color (differential conditioning). Absolute conditioning allows for rapid learning, but color discrimination is coarse. Differential conditioning requires more learning trials, but enables fine discriminations. Currently it is unknown whether differential conditioning to similar colors in honeybees forms a long-term memory, and the stability of memory in a biologically relevant scenario considering similar or saliently different color stimuli. Individual free-flying honeybees (N = 6) were trained to similar color stimuli separated by 0.06 hexagon units for 60 trials and mean accuracy was 81.7% ± 12.2% s.d. Bees retested on subsequent days showed a reduction in the number of correct choices with increasing time from the initial training, and for four of the bees this reduction was significant from chance expectation considering binomially distributed logistic regression models. In contrast, an independent group of 6 bees trained to saliently different colors (>0.14 hexagon units) did not experience any decay in memory retention with increasing time. This suggests that whilst the bees’ visual system can permit fine discriminations, flowers producing saliently different colors are more easily remembered by foraging bees over several days. PMID:26462830

Color Difference and Memory Recall in Free-Flying Honeybees: Forget the Hard Problem.

PubMed

Dyer, Adrian G; Garcia, Jair E

2014-07-30

Free-flying honeybees acquire color information differently depending upon whether a target color is learnt in isolation (absolute conditioning), or in relation to a perceptually similar color (differential conditioning). Absolute conditioning allows for rapid learning, but color discrimination is coarse. Differential conditioning requires more learning trials, but enables fine discriminations. Currently it is unknown whether differential conditioning to similar colors in honeybees forms a long-term memory, and the stability of memory in a biologically relevant scenario considering similar or saliently different color stimuli. Individual free-flying honeybees (N = 6) were trained to similar color stimuli separated by 0.06 hexagon units for 60 trials and mean accuracy was 81.7% ± 12.2% s.d. Bees retested on subsequent days showed a reduction in the number of correct choices with increasing time from the initial training, and for four of the bees this reduction was significant from chance expectation considering binomially distributed logistic regression models. In contrast, an independent group of 6 bees trained to saliently different colors (>0.14 hexagon units) did not experience any decay in memory retention with increasing time. This suggests that whilst the bees' visual system can permit fine discriminations, flowers producing saliently different colors are more easily remembered by foraging bees over several days.

AmTAR2: Functional characterization of a honeybee tyramine receptor stimulating adenylyl cyclase activity.

PubMed

Reim, Tina; Balfanz, Sabine; Baumann, Arnd; Blenau, Wolfgang; Thamm, Markus; Scheiner, Ricarda

2017-01-01

The biogenic monoamines norepinephrine and epinephrine regulate important physiological functions in vertebrates. Insects such as honeybees do not synthesize these neuroactive substances. Instead, they employ octopamine and tyramine for comparable physiological functions. These biogenic amines activate specific guanine nucleotide-binding (G) protein-coupled receptors (GPCRs). Based on pharmacological data obtained on heterologously expressed receptors, α- and β-adrenergic-like octopamine receptors are better activated by octopamine than by tyramine. Conversely, GPCRs forming the type 1 tyramine receptor clade (synonymous to octopamine/tyramine receptors) are better activated by tyramine than by octopamine. More recently, receptors were characterized which are almost exclusively activated by tyramine, thus forming an independent type 2 tyramine receptor clade. Functionally, type 1 tyramine receptors inhibit adenylyl cyclase activity, leading to a decrease in intracellular cAMP concentration ([cAMP] i ). Type 2 tyramine receptors can mediate Ca 2+ signals or both Ca 2+ signals and effects on [cAMP] i . We here provide evidence that the honeybee tyramine receptor 2 (AmTAR2), when heterologously expressed in flpTM cells, exclusively causes an increase in [cAMP] i . The receptor displays a pronounced preference for tyramine over octopamine. Its activity can be blocked by a series of established antagonists, of which mianserin and yohimbine are most efficient. The functional characterization of two tyramine receptors from the honeybee, AmTAR1 (previously named AmTYR1) and AmTAR2, which respond to tyramine by changing cAMP levels in opposite direction, is an important step towards understanding the actions of tyramine in honeybee behavior and physiology, particularly in comparison to the effects of octopamine. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chronic neonicotinoid pesticide exposure and parasite stress differentially affects learning in honeybees and bumblebees

PubMed Central

2016-01-01

Learning and memory are crucial functions which enable insect pollinators to efficiently locate and extract floral rewards. Exposure to pesticides or infection by parasites may cause subtle but ecologically important changes in cognitive functions of pollinators. The potential interactive effects of these stressors on learning and memory have not yet been explored. Furthermore, sensitivity to stressors may differ between species, but few studies have compared responses in different species. Here, we show that chronic exposure to field-realistic levels of the neonicotinoid clothianidin impaired olfactory learning acquisition in honeybees, leading to potential impacts on colony fitness, but not in bumblebees. Infection by the microsporidian parasite Nosema ceranae slightly impaired learning in honeybees, but no interactive effects were observed. Nosema did not infect bumblebees (3% infection success). Nevertheless, Nosema-treated bumblebees had a slightly lower rate of learning than controls, but faster learning in combination with neonicotinoid exposure. This highlights the potential for complex interactive effects of stressors on learning. Our results underline that one cannot readily extrapolate findings from one bee species to others. This has important implications for regulatory risk assessments which generally use honeybees as a model for all bees. PMID:27053744

Multifractality in individual honeybee behavior hints at colony-specific social cascades: Reanalysis of radio-frequency identification data from five different colonies

NASA Astrophysics Data System (ADS)

Carver, Nicole S.; Kelty-Stephen, Damian G.

2017-02-01

Honeybees (Apis mellifera) exhibit complex coordination and interaction across multiple behaviors such as swarming. This coordination among honeybees in the same colony is remarkably similar to the concept of informational cascades. The multifractal geometry of cascades suggests that multifractal measures of individual honeybee activity might carry signatures of these colony-wide coordinations. The present work reanalyzes time stamps of entrances to and exits from the hive captured by radio-frequency identification (RFID) sensors reading RFID tags on individual bees. Indeed, both multifractal spectrum width for individual bees' inter-reading interval series and differences of those widths from surrogates significantly predicted not just whether the individual bee's hive had a mesh enclosure but also predicted the specific membership of individual bees in one of five colonies. The significant effects of multifractality in matching honeybee activity to type of colony and, further, matching individual honeybees to their exact home colony suggests that multifractality quantifies key features of the colony-wide interactions across many scales. This relevance of multifractality to predicting colony type or colony membership adds additional credence to the cascade metaphor for colony organization. Perhaps, multifractality provides a new tool for exploring the relationship between individual organisms and larger, more complex social behaviors.

Field-relevant doses of the systemic insecticide fipronil and fungicide pyraclostrobin impair mandibular and hypopharyngeal glands in nurse honeybees (Apis mellifera).

PubMed

Zaluski, Rodrigo; Justulin, Luis Antonio; Orsi, Ricardo de Oliveira

2017-11-09

Global decreases in bee populations emphasize the importance of assessing how environmental stressors affect colony maintenance, especially considering the extreme task specialization observed in honeybee societies. Royal jelly, a protein secretion essential to colony nutrition, is produced by nurse honeybees, and development of bee mandibular glands, which comprise a reservoir surrounded by secretory cells and hypopharyngeal glands that are shaped by acini, is directly associated with production of this secretion. Here, we examined individual and combined effects of the systemic fungicide pyraclostrobin and insecticide fipronil in field-relevant doses (850 and 2.5 ppb, respectively) on mandibular and hypopharyngeal glands in nurse honeybees. Six days of pesticide treatment decreased secretory cell height in mandibular glands. When pyraclostrobin and fipronil were combined, the reservoir volume in mandibular glands also decreased. The total number of acini in hypopharyngeal glands was not affected, but pesticide treatment reduced the number of larger acini while increasing smaller acini. These morphological impairments appeared to reduce royal jelly secretion by nurse honeybees and consequently hampered colony maintenance. Overall, pesticide exposure in doses close to those experienced by bees in the field impaired brood-food glands in nurse honeybees, a change that could negatively influence development, survival, and colony maintenance.

[Effect of high intensity magnetic field on the processes of early growth in plant seeds and development of honeybees].

PubMed

Es'kov, E K; Darkov, A V

2003-01-01

The influence of magnetic field on the early growth processes in plant seeds and the postembryonic development of honeybees was studied. Some general trends in the effects of magnetic field and differences in the tolerance of plant seeds and developing honeybees to its action were revealed. Some factors that may be responsible for a low reproducibility of magneto-biological effects are discussed.

Appetitive but Not Aversive Olfactory Conditioning Modifies Antennal Movements in Honeybees

ERIC Educational Resources Information Center

Cholé, Hanna; Junca, Pierre; Sandoz, Jean-Christophe

2015-01-01

In honeybees, two olfactory conditioning protocols allow the study of appetitive and aversive Pavlovian associations. Appetitive conditioning of the proboscis extension response (PER) involves associating an odor, the conditioned stimulus (CS) with a sucrose solution, the unconditioned stimulus (US). Conversely, aversive conditioning of the sting…

Interspecific utilisation of wax in comb building by honeybees

NASA Astrophysics Data System (ADS)

Hepburn, H. Randall; Radloff, Sarah E.; Duangphakdee, Orawan; Phaincharoen, Mananya

2009-06-01

Beeswaxes of honeybee species share some homologous neutral lipids; but species-specific differences remain. We analysed behavioural variation for wax choice in honeybees, calculated the Euclidean distances for different beeswaxes and assessed the relationship of Euclidean distances to wax choice. We tested the beeswaxes of Apis mellifera capensis, Apis florea, Apis cerana and Apis dorsata and the plant and mineral waxes Japan, candelilla, bayberry and ozokerite as sheets placed in colonies of A. m. capensis, A. florea and A. cerana. A. m. capensis accepted the four beeswaxes but removed Japan and bayberry wax and ignored candelilla and ozokerite. A. cerana colonies accepted the wax of A. cerana, A. florea and A. dorsata but rejected or ignored that of A. m. capensis, the plant and mineral waxes. A. florea colonies accepted A. cerana, A. dorsata and A. florea wax but rejected that of A. m. capensis. The Euclidean distances for the beeswaxes are consistent with currently prevailing phylogenies for Apis. Despite post-speciation chemical differences in the beeswaxes, they remain largely acceptable interspecifically while the plant and mineral waxes are not chemically close enough to beeswax for their acceptance.

Neonicotinoid-induced impairment of odour coding in the honeybee

PubMed Central

Andrione, Mara; Vallortigara, Giorgio; Antolini, Renzo; Haase, Albrecht

2016-01-01

Exposure to neonicotinoid pesticides is considered one of the possible causes of honeybee (Apis mellifera) population decline. At sublethal doses, these chemicals have been shown to negatively affect a number of behaviours, including performance of olfactory learning and memory, due to their interference with acetylcholine signalling in the mushroom bodies. Here we provide evidence that neonicotinoids can affect odour coding upstream of the mushroom bodies, in the first odour processing centres of the honeybee brain, i.e. the antennal lobes (ALs). In particular, we investigated the effects of imidacloprid, the most common neonicotinoid, in the AL glomeruli via in vivo two-photon calcium imaging combined with pulsed odour stimulation. Following acute imidacloprid treatment, odour-evoked calcium response amplitude in single glomeruli decreases, and at the network level the representations of different odours are no longer separated. This demonstrates that, under neonicotinoid influence, olfactory information might reach the mushroom bodies in a form that is already incorrect. Thus, some of the impairments in olfactory learning and memory caused by neonicotinoids could, in fact, arise from the disruption in odor coding and olfactory discrimination ability of the honey bees. PMID:27905515

Spatial memory and navigation by honeybees on the scale of the foraging range

PubMed

Dyer

1996-01-01

Honeybees and other nesting animals face the problem of finding their way between their nest and distant feeding sites. Many studies have shown that insects can learn foraging routes in reference to both landmarks and celestial cues, but it is a major puzzle how spatial information obtained from these environmental features is encoded in memory. This paper reviews recent progress by my colleagues and me towards understanding three specific aspects of this problem in honeybees: (1) how bees learn the spatial relationships among widely separated locations in a familiar terrain; (2) how bees learn the pattern of movement of the sun over the day; and (3) whether, and if so how, bees learn the relationships between celestial cues and landmarks.

Acute contact toxicity test of insecticides (Cipermetrina 25, Lorsban 48E, Thionex 35) on honeybees in the southwestern zone of Uruguay.

PubMed

Carrasco-Letelier, Leonidas; Mendoza-Spina, Yamandú; Branchiccela, María Belén

2012-07-01

Glyphosate-resistant soybean cultivation is expanding rapidly in Uruguay, with its land area having increased by 95 times during the past 10 years. Because of the region's Neotropical conditions, insecticide use is required to ensure adequate soybean productivity. However, in areas shared by soybean crops and beekeepers - such as the southwestern zone of Uruguay (SWZU) - the use of insecticides can increase the risks of honeybee death and honey contamination. Uruguayan commercial and legal guidelines set out practices and field doses designed to prevent acute intoxication with insecticides. However, honeybees in the SWZU are predominantly a polyhybrid subspecies different from that used to set international reference values, and hence they may have a different acute toxicity response, thus rendering such precautions ineffective. The aim of this work was to assess the acute toxicity response of polyhybrid honeybees in the SWZU to cypermethrin (commercial formulation: Cipermetrina 25 Agrin®), chlorpyrifos (commercial formulation: Lorsban 48E®), and endosulfan (commercial formulation: Thionex 35®). Acute toxicity bioassays were conducted to determine the median lethal dose (LD(50)) of each insecticide for the honeybees. The results indicate that, compared with EU reference values, SWZU honeybees have a higher toxicological sensitivity to chlorpyrifos and endosulfan, and a lower toxicological sensitivity to cypermethrin, based on the commercial formulations tested. However, when these results were adjusted according to their field dose equivalents, only chlorpyrifos emerged as a potential problem for beekeeping, as the maximum recommended field dose of Lorsban 48E® for soybean crops in Uruguay is 23 times the corresponding LD(50) for honeybees in the SWZU. Copyright © 2012 Elsevier Ltd. All rights reserved.

More than royal food - Major royal jelly protein genes in sexuals and workers of the honeybee Apis mellifera.

PubMed

Buttstedt, Anja; Moritz, Robin Fa; Erler, Silvio

2013-11-27

In the honeybee Apis mellifera, female larvae destined to become a queen are fed with royal jelly, a secretion of the hypopharyngeal glands of young nurse bees that rear the brood. The protein moiety of royal jelly comprises mostly major royal jelly proteins (MRJPs) of which the coding genes (mrjp1-9) have been identified on chromosome 11 in the honeybee's genome. We determined the expression of mrjp1-9 among the honeybee worker caste (nurses, foragers) and the sexuals (queens (unmated, mated) and drones) in various body parts (head, thorax, abdomen). Specific mrjp expression was not only found in brood rearing nurse bees, but also in foragers and the sexuals. The expression of mrjp1 to 7 is characteristic for the heads of worker bees, with an elevated expression of mrjp1-4 and 7 in nurse bees compared to foragers. Mrjp5 and 6 were higher in foragers compared to nurses suggesting functions in addition to those of brood food proteins. Furthermore, the expression of mrjp9 was high in the heads, thoraces and abdomen of almost all female bees, suggesting a function irrespective of body section. This completely different expression profile suggests mrjp9 to code for the most ancestral major royal jelly protein of the honeybee.

Sleep Deprivation affects Extinction but Not Acquisition Memory in Honeybees

ERIC Educational Resources Information Center

Hussaini, Syed Abid; Bogusch, Lisa; Landgraf, Tim; Menzel, Randolf

2009-01-01

Sleep-like behavior has been studied in honeybees before, but the relationship between sleep and memory formation has not been explored. Here we describe a new approach to address the question if sleep in bees, like in other animals, improves memory consolidation. Restrained bees were observed by a web camera, and their antennal activities were…

Do honeybees, Apis mellifera scutellata, regulate humidity in their nest?

NASA Astrophysics Data System (ADS)

Human, Hannelie; Nicolson, Sue W.; Dietemann, Vincent

2006-08-01

Honeybees are highly efficient at regulating the biophysical parameters of their hive according to colony needs. Thermoregulation has been the most extensively studied aspect of nest homeostasis. In contrast, little is known about how humidity is regulated in beehives, if at all. Although high humidity is necessary for brood development, regulation of this parameter by honeybee workers has not yet been demonstrated. In the past, humidity was measured too crudely for a regulation mechanism to be identified. We reassess this issue, using miniaturised data loggers that allow humidity measurements in natural situations and at several places in the nest. We present evidence that workers influence humidity in the hive. However, there are constraints on potential regulation mechanisms because humidity optima may vary in different locations of the nest. Humidity could also depend on variable external factors, such as water availability, which further impair the regulation. Moreover, there are trade-offs with the regulation of temperature and respiratory gas exchanges that can disrupt the establishment of optimal humidity levels. As a result, we argue that workers can only adjust humidity within sub-optimal limits.

Observations and temporal model of a honeybee's hairy tongue in microfluid transport

NASA Astrophysics Data System (ADS)

Zhao, Chenjia; Wu, Jianing; Yan, Shaoze

2015-11-01

Nectarivorous insects are endowed with specific mouthparts, which provide an inspiration for the design of micropumps. We combined the postmortem examination and high-speed imaging to observe the kinematics of the honeybee's tongue. We found an asynchronization between the tongue movement and the glossa hair erection. We propose a physical model to describe the feeding process considering the trade-off between nectar-intake volume and energy consumption. This asynchronization is validated to be effective in maximizing the nectar-intake amount by theoretically figuring out the optimal moment when the glossal hairs began to erect. Our results reveal that the honeybee not only develops a subtle tongue with erectable glossal hairs but also preforms a highly evolved scheduled coordination between tongue movements and hair erection, which could serve as valuable models for developing miniature pumps that are both extendable and have dynamic surfaces.

Application of the combination index (CI)-isobologram equation to research the toxicological interactions of clothianidin, thiamethoxam, and dinotefuran in honeybee, Apis mellifera.

PubMed

Liu, Yanmei; Liu, Sihong; Zhang, Hui; Gu, Yanping; Li, Xuesheng; He, Mingyuan; Tan, Huihua

2017-10-01

Due to complex pest control scenarios and the needs of agricultural production, different neonicotinoids may be used in certain agricultural applications. Consequently, honeybees may be exposed to these substances through distribution throughout plant tissues via the vascular system through several pathways, such as surface water, the exudates excreted from plants, and air pollution via drift of dust as well as contaminated pollen and nectar. In the current study, the single and combined toxicity of clothianidin, dinotefuran, and thiamethoxam to honeybees was examined after 48 h exposure by the acute oral method and combination index (CI)-isobologram equation. At the 48 h interval, our results showed that 1) the order of toxicities for the single insecticides was ranked as clothianidin > thiamethoxam > dinotefuran and that 2) all binary and ternary combinations showed synergism or additive effect at the effect (f a ) 0.5. Therefore, our results not only provided meaningful guidelines in evaluating the safety risk of the mixtures of the three neonicotinoids towards honeybees but also suggested that there is a significant interest in the study of mixture toxicities of neonicotinoids against honeybees because risk assessment of neonicotinoids against honeybees conducted only in individual insecticides may underestimate the realistic toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic underpinnings of division of labor in the honeybee (Apis mellifera).

PubMed

Lattorff, H Michael G; Moritz, Robin F A

2013-11-01

Honeybees have been studied for centuries, starting with Aristotle, who wrote the first book about bee breeding. More than 2000 years later, the honeybee entered the genomic era as the first social insect whose genome was sequenced, leading to significant insight into the molecular mechanisms underlying social behavior. In addition, gene expression studies and knockdown using RNAi have extended the understanding of social interactions. Much of the work has focused on caste determination - the mechanism that results in reproductive division of labor, division of labor within the worker caste, and worker reproduction - an essential process underlying eusociality. Here we review the molecular factors involved in caste determination and the differential regulation of caste-specific genes. Recent findings suggest that division of labor is influenced by a small number of loci showing high levels of pleiotropy, suggesting that changes in a small number of genes lead to large changes in the phenotype. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Darwin cure for apiculture? Natural selection and managed honeybee health.

PubMed

Neumann, Peter; Blacquière, Tjeerd

2017-03-01

Recent major losses of managed honeybee, Apis mellifera, colonies at a global scale have resulted in a multitude of research efforts to identify the underlying mechanisms. Numerous factors acting singly and/or in combination have been identified, ranging from pathogens, over nutrition to pesticides. However, the role of apiculture in limiting natural selection has largely been ignored. This is unfortunate, because honeybees are more exposed to environmental stressors compared to other livestock and management can severely compromise bee health. Here, we briefly review apicultural factors that influence bee health and focus on those most likely interfering with natural selection, which offers a broad range of evolutionary applications for field practice. Despite intense breeding over centuries, natural selection appears to be much more relevant for the health of managed A. mellifera colonies than previously thought. We conclude that sustainable solutions for the apicultural sector can only be achieved by taking advantage of natural selection and not by attempting to limit it.

Transcriptome differences in the hypopharyngeal gland between Western Honeybees (Apis mellifera) and Eastern Honeybees (Apis cerana).

PubMed

Liu, Hao; Wang, Zi-Long; Tian, Liu-Qing; Qin, Qiu-Hong; Wu, Xiao-Bo; Yan, Wei-Yu; Zeng, Zhi-Jiang

2014-08-30

Apis mellifera and Apis cerana are two sibling species of Apidae. Apis cerana is adept at collecting sporadic nectar in mountain and forest region and exhibits stiffer hardiness and acarid resistance as a result of natural selection, whereas Apis mellifera has the advantage of producing royal jelly. To identify differentially expressed genes (DEGs) that affect the development of hypopharyngeal gland (HG) and/or the secretion of royal jelly between these two honeybee species, we performed a digital gene expression (DGE) analysis of the HGs of these two species at three developmental stages (newly emerged worker, nurse and forager). Twelve DGE-tag libraries were constructed and sequenced using the total RNA extracted from the HGs of newly emerged workers, nurses, and foragers of Apis mellifera and Apis cerana. Finally, a total of 1482 genes in Apis mellifera and 1313 in Apis cerana were found to exhibit an expression difference among the three developmental stages. A total of 1417 DEGs were identified between these two species. Of these, 623, 1072, and 462 genes showed an expression difference at the newly emerged worker, nurse, and forager stages, respectively. The nurse stage exhibited the highest number of DEGs between these two species and most of these were found to be up-regulated in Apis mellifera. These results suggest that the higher yield of royal jelly in Apis mellifera may be due to the higher expression level of these DEGs. In this study, we investigated the DEGs between the HGs of two sibling honeybee species (Apis mellifera and Apis cerana). Our results indicated that the gene expression difference was associated with the difference in the royal jelly yield between these two species. These results provide an important clue for clarifying the mechanisms underlying hypopharyngeal gland development and the production of royal jelly.

Duration of the Unconditioned Stimulus in Appetitive Conditioning of Honeybees Differentially Impacts Learning, Long-Term Memory Strength, and the Underlying Protein Synthesis

ERIC Educational Resources Information Center

Marter, Kathrin; Grauel, M. Katharina; Lewa, Carmen; Morgenstern, Laura; Buckemüller, Christina; Heufelder, Karin; Ganz, Marion; Eisenhardt, Dorothea

2014-01-01

This study examines the role of stimulus duration in learning and memory formation of honeybees ("Apis mellifera"). In classical appetitive conditioning honeybees learn the association between an initially neutral, conditioned stimulus (CS) and the occurrence of a meaningful stimulus, the unconditioned stimulus (US). Thereby the CS…

Temperature dependent virulence of obligate and facultative fungal pathogens of honeybee brood

USDA-ARS?s Scientific Manuscript database

Chalkbrood (Ascosphaera apis) and stonebrood (Aspergillus flavus) are well known fungal brood diseases of honeybees (Apis mellifera), but they have hardly been systematically studied because the difficulty of rearing larvae in vitro has precluded controlled experimentation. Chalkbrood is a chronic h...

Evidence for instantaneous e-vector detection in the honeybee using an associative learning paradigm

PubMed Central

Sakura, Midori; Okada, Ryuichi; Aonuma, Hitoshi

2012-01-01

Many insects use the polarization pattern of the sky for obtaining compass information during orientation or navigation. E-vector information is collected by a specialized area in the dorsal-most part of the compound eye, the dorsal rim area (DRA). We tested honeybees' capability of learning certain e-vector orientations by using a classical conditioning paradigm with the proboscis extension reflex. When one e-vector orientation (CS+) was associated with sugar water, while another orientation (CS−) was not rewarded, the honeybees could discriminate CS+ from CS−. Bees whose DRA was inactivated by painting did not learn CS+. When ultraviolet (UV) polarized light (350 nm) was used for CS, the bees discriminated CS+ from CS−, but no discrimination was observed in blue (442 nm) or green light (546 nm). Our data indicate that honeybees can learn and discriminate between different e-vector orientations, sensed by the UV receptors of the DRA, suggesting that bees can determine their flight direction from polarized UV skylight during foraging. Fixing the bees' heads during the experiments did not prevent learning, indicating that they use an ‘instantaneous’ algorithm of e-vector detection; that is, the bees do not need to actively scan the sky with their DRAs (‘sequential’ method) to determine e-vector orientation. PMID:21733901

Bacterial community associated with worker honeybees (Apis mellifera) affected by European foulbrood

PubMed Central

Ledvinka, Ondrej; Kamler, Martin; Hortova, Bronislava; Nesvorna, Marta; Tyl, Jan; Titera, Dalibor; Markovic, Martin; Hubert, Jan

2017-01-01

Background Melissococcus plutonius is an entomopathogenic bacterium that causes European foulbrood (EFB), a honeybee (Apis mellifera L.) disease that necessitates quarantine in some countries. In Czechia, positive evidence of EFB was absent for almost 40 years, until an outbreak in the Krkonose Mountains National Park in 2015. This occurrence of EFB gave us the opportunity to study the epizootiology of EFB by focusing on the microbiome of honeybee workers, which act as vectors of honeybee diseases within and between colonies. Methods The study included worker bees collected from brood combs of colonies (i) with no signs of EFB (EFB0), (ii) without clinical symptoms but located at an apiary showing clinical signs of EFB (EFB1), and (iii) with clinical symptoms of EFB (EFB2). In total, 49 samples from 27 honeybee colonies were included in the dataset evaluated in this study. Each biological sample consisted of 10 surface-sterilized worker bees processed for DNA extraction. All subjects were analyzed using conventional PCR and by metabarcoding analysis based on the 16S rRNA gene V1–V3 region, as performed through Illumina MiSeq amplicon sequencing. Results The bees from EFB2 colonies with clinical symptoms exhibited a 75-fold-higher incidence of M. plutonius than those from EFB1 asymptomatic colonies. Melissococcus plutonius was identified in all EFB1 colonies as well as in some of the control colonies. The proportions of Fructobacillus fructosus, Lactobacillus kunkeei, Gilliamella apicola, Frischella perrara, and Bifidobacterium coryneforme were higher in EFB2 than in EFB1, whereas Lactobacillus mellis was significantly higher in EFB2 than in EFB0. Snodgrassella alvi and L. melliventris, L. helsingborgensis and, L. kullabergensis exhibited higher proportion in EFB1 than in EFB2 and EFB0. The occurrence of Bartonella apis and Commensalibacter intestini were higher in EFB0 than in EFB2 and EFB1. Enterococcus faecalis incidence was highest in EFB2. Conclusions High

Effects of field-realistic doses of glyphosate on honeybee appetitive behaviour.

PubMed

Herbert, Lucila T; Vázquez, Diego E; Arenas, Andrés; Farina, Walter M

2014-10-01

Glyphosate (GLY) is a broad-spectrum herbicide used for weed control. The sub-lethal impact of GLY on non-target organisms such as insect pollinators has not yet been evaluated. Apis mellifera is the main pollinator in agricultural environments and is a well-known model for behavioural research. Honeybees are also accurate biosensors of environmental pollutants and their appetitive behavioural response is a suitable tool with which to test sub-lethal effects of agrochemicals. We studied the effects of field-realistic doses of GLY on honeybees exposed chronically or acutely to the herbicide. We focused on sucrose sensitivity, elemental and non-elemental associative olfactory conditioning of the proboscis extension response (PER), and foraging-related behaviour. We found a reduced sensitivity to sucrose and learning performance for the groups chronically exposed to GLY concentrations within the range of recommended doses. When olfactory PER conditioning was performed with sucrose reward with the same GLY concentrations (acute exposure), elemental learning and short-term memory retention decreased significantly compared with controls. Non-elemental associative learning was also impaired by an acute exposure to GLY traces. Altogether, these results imply that GLY at concentrations found in agro-ecosystems as a result of standard spraying can reduce sensitivity to nectar reward and impair associative learning in honeybees. However, no effect on foraging-related behaviour was found. Therefore, we speculate that successful forager bees could become a source of constant inflow of nectar with GLY traces that could then be distributed among nestmates, stored in the hive and have long-term negative consequences on colony performance. © 2014. Published by The Company of Biologists Ltd.

Flight, orientation, and homing abilities of honeybees following exposure to 2.45-GHz CW microwaves.

PubMed

Gary, N E; Westerdahl, B B

1981-01-01

Foraging-experienced honeybees retained normal flight, orientation, and memory functions after 30 minutes' exposure to 2.45-GHz CW microwaves at power densities from 3 to 50 mW/cm2. These experiments were conducted at power densities approximating and exceeding those that would be present above receiving antennas of the proposed solar power satellite (SPS) energy transmission system and for a duration exceeding that which honeybees living outside a rectenna might be expected to spend within the rectenna on individual foraging trips. There was no evidence that airborne invertebrates would be significantly affected during transient passage through microwaves associated with SPS ground-based microwave receiving stations.

Low fertility, fecundity and numbers of mated female offspring explain the lower reproductive success of the parasitic mite Varroa destructor in African honeybees

USDA-ARS?s Scientific Manuscript database

Although Varroa destructor is the most serious ecto-parasite to the honeybee, Apis mellifera L., some honeybee populations such as Apis mellifera scutellata in Kenya can survive mite infestations without treatment. Previously, we reported that grooming behavior could be a potential tolerant mechanis...

Alternative splicing of a single transcription factor drives selfish reproductive behavior in honeybee workers (Apis mellifera).

PubMed

Jarosch, Antje; Stolle, Eckart; Crewe, Robin M; Moritz, Robin F A

2011-09-13

In eusocial insects the production of daughters is generally restricted to mated queens, and unmated workers are functionally sterile. The evolution of this worker sterility has been plausibly explained by kin selection theory [Hamilton W (1964) J Theor Biol 7:1-52], and many traits have evolved to prevent conflict over reproduction among the females in an insect colony. In honeybees (Apis mellifera), worker reproduction is regulated by the queen, brood pheromones, and worker policing. However, workers of the Cape honeybee, Apis mellifera capensis, can evade this control and establish themselves as social parasites by activating their ovaries, parthenogenetically producing diploid female offspring (thelytoky) and producing queen-like amounts of queen pheromones. All these traits have been shown to be strongly influenced by a single locus on chromosome 13 [Lattorff HMG, et al. (2007) Biol Lett 3:292-295]. We screened this region for candidate genes and found that alternative splicing of a gene homologous to the gemini transcription factor of Drosophila controls worker sterility. Knocking out the critical exon in a series of RNAi experiments resulted in rapid worker ovary activation-one of the traits characteristic of the social parasites. This genetic switch may be controlled by a short intronic splice enhancer motif of nine nucleotides attached to the alternative splice site. The lack of this motif in parasitic Cape honeybee clones suggests that the removal of nine nucleotides from the altruistic worker genome may be sufficient to turn a honeybee from an altruistic worker into a parasite.

Interactive Effects of Large- and Small-Scale Sources of Feral Honey-Bees for Sunflower in the Argentine Pampas

PubMed Central

Sáez, Agustín; Sabatino, Malena; Aizen, Marcelo A.

2012-01-01

Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha) of natural habitat, represented by untilled isolated “sierras”, and narrow (3–7 m wide) strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus). We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group) at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0–10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services. PMID:22303477

Interactive effects of large- and small-scale sources of feral honey-bees for sunflower in the Argentine Pampas.

PubMed

Sáez, Agustín; Sabatino, Malena; Aizen, Marcelo A

2012-01-01

Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha) of natural habitat, represented by untilled isolated "sierras", and narrow (3-7 m wide) strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus). We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group) at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0-10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services.

How do honeybees use their magnetic compass? Can they see the North?

PubMed

Válková, T; Vácha, M

2012-08-01

While seeking food sources and routes back to their hive, bees make use of their advanced nervous and sensory capacities, which underlie a diverse behavioral repertoire. One of several honeybee senses that is both exceptional and intriguing is magnetoreception - the ability to perceive the omnipresent magnetic field (MF) of the Earth. The mechanism by which animals sense MFs has remained fascinating as well as elusive because of the intricacies involved, which makes it one of the grand challenges for neural and sensory biology. However, investigations in recent years have brought substantial progress to our understanding of how such magneto-receptor(s) may work. Some terrestrial animals (birds) are reported to be equipped even with a dual perception system: one based on diminutive magnetic particles - in line with the original model which has also always been hypothesized for bees - and the other one, as the more recent model describes, based on a sensitivity of some photochemical reactions to MF (radical-pair or chemical mechanism). The latter model postulates a close link to vision and supposes that the animals can see the position of the geomagnetic North as a visible pattern superimposed on the picture of the environment. In recent years, a growing body of evidence has shown that radical-pair magnetoreception might also be used by insects. It is realistic to expect that such evidence will inspire a re-examination and extension or confirmation of established views on the honeybee magnetic-compass mechanism. However, the problem of bee magnetoreception will not be solved at the moment that a receptor is discovered. On the contrary, the meaning of magnetoreception in insect life and its involvement in the orchestration of other senses is yet to be fully understood. The crucial question to be addressed in the near future is whether the compass abilities of the honeybee could suffer from radio frequency (RF) smog accompanying modern civilization and whether the

Gigantism in honeybees: Apis cerana queens reared in mixed-species colonies

NASA Astrophysics Data System (ADS)

Tan, Ken; Hepburn, H. R.; He, Shaoyu; Radloff, S. E.; Neumann, P.; Fang, Xiang

2006-07-01

The development of animals depends on both genetic and environmental effects to a varying extent. Their relative influences can be evaluated in the social insects by raising the intracolonial diversity to an extreme in nests consisting of workers from more than one species. In this study, we studied the effects of mixed honeybee colonies of Apis mellifera and Apis cerana on the rearing of grafted queen larvae of A. cerana. A. mellifera sealed worker brood was introduced into A. cerana colonies and on emergence, the adults were accepted. Then, A. cerana larvae were grafted for queen rearing into two of these mixed-species colonies. Similarly, A. cerana larvae and A. mellifera larvae were also grafted conspecifically as controls. The success rate of A. cerana queen rearing in the test colonies was 64.5%, surpassing all previous attempts at interspecific queen rearing. After emergence, all virgin queens obtained from the three groups ( N=90) were measured morphometrically. The A. cerana queens from the mixed-species colonies differed significantly in size and pigmentation from the A. cerana control queens and closely approximated the A. mellifera queens. It is inferred that these changes in the A. cerana queens reared in the mixed-species colonies can be attributed to feeding by heterospecific nurse bees and/or chemical differences in royal jelly. Our data show a strong impact of environment on the development of queens. The results further suggest that in honeybees the cues for brood recognition can be learned by heterospecific workers after eclosion, thereby providing a novel analogy to slave making in ants.

An abbreviated SNP panel for ancestry assignment of honeybees (Apis mellifera)

USDA-ARS?s Scientific Manuscript database

This paper examines whether an abbreviated panel of 37 single nucleotide polymorphisms (SNPs) has the same power as a larger and more expensive panel of 95 SNPs to assign ancestry of honeybees (Apis mellifera) to three ancestral lineages. We selected 37 SNPs from the original 95 SNP panel using alle...

Resolution and sensitivity of the eyes of the Asian honeybees Apis florea, Apis cerana and Apis dorsata.

PubMed

Somanathan, Hema; Warrant, Eric J; Borges, Renee M; Wallén, Rita; Kelber, Almut

2009-08-01

Bees of the genus Apis are important foragers of nectar and pollen resources. Although the European honeybee, Apis mellifera, has been well studied with respect to its sensory abilities, learning behaviour and role as pollinators, much less is known about the other Apis species. We studied the anatomical spatial resolution and absolute sensitivity of the eyes of three sympatric species of Asian honeybees, Apis cerana, Apis florea and Apis dorsata and compared them with the eyes of A. mellifera. Of these four species, the giant honeybee A. dorsata (which forages during moonlit nights) has the lowest spatial resolution and the most sensitive eyes, followed by A. mellifera, A. cerana and the dwarf honeybee, A. florea (which has the smallest acceptance angles and the least sensitive eyes). Moreover, unlike the strictly diurnal A. cerana and A. florea, A. dorsata possess large ocelli, a feature that it shares with all dim-light bees. However, the eyes of the facultatively nocturnal A. dorsata are much less sensitive than those of known obligately nocturnal bees such as Megalopta genalis in Panama and Xylocopa tranquebarica in India. The differences in sensitivity between the eyes of A. dorsata and other strictly diurnal Apis species cannot alone explain why the former is able to fly, orient and forage at half-moon light levels. We assume that additional neuronal adaptations, as has been proposed for A. mellifera, M. genalis and X. tranquebarica, might exist in A. dorsata.

A Strong Immune Response in Young Adult Honeybees Masks Their Increased Susceptibility to Infection Compared to Older Bees

PubMed Central

Bull, James C.; Ryabov, Eugene V.; Prince, Gill; Mead, Andrew; Zhang, Cunjin; Baxter, Laura A.; Pell, Judith K.; Osborne, Juliet L.; Chandler, Dave

2012-01-01

Honeybees, Apis mellifera, show age-related division of labor in which young adults perform maintenance (“housekeeping”) tasks inside the colony before switching to outside foraging at approximately 23 days old. Disease resistance is an important feature of honeybee biology, but little is known about the interaction of pathogens and age-related division of labor. We tested a hypothesis that older forager bees and younger “house” bees differ in susceptibility to infection. We coupled an infection bioassay with a functional analysis of gene expression in individual bees using a whole genome microarray. Forager bees treated with the entomopathogenic fungus Metarhizium anisopliae s.l. survived for significantly longer than house bees. This was concomitant with substantial differences in gene expression including genes associated with immune function. In house bees, infection was associated with differential expression of 35 candidate immune genes contrasted with differential expression of only two candidate immune genes in forager bees. For control bees (i.e. not treated with M. anisopliae) the development from the house to the forager stage was associated with differential expression of 49 candidate immune genes, including up-regulation of the antimicrobial peptide gene abaecin, plus major components of the Toll pathway, serine proteases, and serpins. We infer that reduced pathogen susceptibility in forager bees was associated with age-related activation of specific immune system pathways. Our findings contrast with the view that the immunocompetence in social insects declines with the onset of foraging as a result of a trade-off in the allocation of resources for foraging. The up-regulation of immune-related genes in young adult bees in response to M. anisopliae infection was an indicator of disease susceptibility; this also challenges previous research in social insects, in which an elevated immune status has been used as a marker of increased disease

Assessing honeybee and wasp thermoregulation and energetics—New insights by combination of flow-through respirometry with infrared thermography

PubMed Central

Stabentheiner, Anton; Kovac, Helmut; Hetz, Stefan K.; Käfer, Helmut; Stabentheiner, Gabriel

2012-01-01

Endothermic insects like honeybees and some wasps have to cope with an enormous heat loss during foraging because of their small body size in comparison to endotherms like mammals and birds. The enormous costs of thermoregulation call for optimisation. Honeybees and wasps differ in their critical thermal maximum, which enables the bees to kill the wasps by heat. We here demonstrate the benefits of a combined use of body temperature measurement with infrared thermography, and respiratory measurements of energy turnover (O2 consumption or CO2 production via flow-through respirometry) to answer questions of insect ecophysiological research, and we describe calibrations to receive accurate results. To assess the question of what foraging honeybees optimise, their body temperature was compared with their energy turnover. Honeybees foraging from an artificial flower with unlimited sucrose flow increased body surface temperature and energy turnover with profitability of foraging (sucrose content of the food; 0.5 or 1.5 mol/L). Costs of thermoregulation, however, were rather independent of ambient temperature (13–30 °C). External heat gain by solar radiation was used to increase body temperature. This optimised foraging energetics by increasing suction speed. In determinations of insect respiratory critical thermal limits, the combined use of respiratory measurements and thermography made possible a more conclusive interpretation of respiratory traces. PMID:22723718

Pyrethroids and Nectar Toxins Have Subtle Effects on the Motor Function, Grooming and Wing Fanning Behaviour of Honeybees (Apis mellifera).

PubMed

Oliver, Caitlin J; Softley, Samantha; Williamson, Sally M; Stevenson, Philip C; Wright, Geraldine A

2015-01-01

Sodium channels, found ubiquitously in animal muscle cells and neurons, are one of the main target sites of many naturally-occurring, insecticidal plant compounds and agricultural pesticides. Pyrethroids, derived from compounds found only in the Asteraceae, are particularly toxic to insects and have been successfully used as pesticides including on flowering crops that are visited by pollinators. Pyrethrins, from which they were derived, occur naturally in the nectar of some flowering plant species. We know relatively little about how such compounds--i.e., compounds that target sodium channels--influence pollinators at low or sub-lethal doses. Here, we exposed individual adult forager honeybees to several compounds that bind to sodium channels to identify whether these compounds affect motor function. Using an assay previously developed to identify the effect of drugs and toxins on individual bees, we investigated how acute exposure to 10 ng doses (1 ppm) of the pyrethroid insecticides (cyfluthrin, tau-fluvalinate, allethrin and permethrin) and the nectar toxins (aconitine and grayanotoxin I) affected honeybee locomotion, grooming and wing fanning behaviour. Bees exposed to these compounds spent more time upside down and fanning their wings. They also had longer bouts of standing still. Bees exposed to the nectar toxin, aconitine, and the pyrethroid, allethrin, also spent less time grooming their antennae. We also found that the concentration of the nectar toxin, grayanotoxin I (GTX), fed to bees affected the time spent upside down (i.e., failure to perform the righting reflex). Our data show that low doses of pyrethroids and other nectar toxins that target sodium channels mainly influence motor function through their effect on the righting reflex of adult worker honeybees.

Lower disease infections in honeybee (Apis mellifera) colonies headed by polyandrous vs monandrous queens

NASA Astrophysics Data System (ADS)

Tarpy, David R.; Seeley, Thomas D.

2006-04-01

We studied the relationship between genetic diversity and disease susceptibility in honeybee colonies living under natural conditions. To do so, we created colonies in which each queen was artificially inseminated with sperm from either one or ten drones. Of the 20 colonies studied, 80% showed at least one brood disease. We found strong differences between the two types of colonies in the infection intensity of chalkbrood and in the total intensity of all brood diseases (chalkbrood, sacbrood, American foulbrood, and European foulbrood) with both variables lower for the colonies with higher genetic diversity. Our findings demonstrate that disease can be an important factor in the ecology of honeybee colonies and they provide strong support for the disease hypothesis for the evolution of polyandry by social insect queens.

Neonicotinoids Interfere with Specific Components of Navigation in Honeybees

PubMed Central

Fischer, Johannes; Müller, Teresa; Spatz, Anne-Kathrin; Greggers, Uwe; Grünewald, Bernd; Menzel, Randolf

2014-01-01

Three neonicotinoids, imidacloprid, clothianidin and thiacloprid, agonists of the nicotinic acetylcholine receptor in the central brain of insects, were applied at non-lethal doses in order to test their effects on honeybee navigation. A catch-and-release experimental design was applied in which feeder trained bees were caught when arriving at the feeder, treated with one of the neonicotinoids, and released 1.5 hours later at a remote site. The flight paths of individual bees were tracked with harmonic radar. The initial flight phase controlled by the recently acquired navigation memory (vector memory) was less compromised than the second phase that leads the animal back to the hive (homing flight). The rate of successful return was significantly lower in treated bees, the probability of a correct turn at a salient landscape structure was reduced, and less directed flights during homing flights were performed. Since the homing phase in catch-and-release experiments documents the ability of a foraging honeybee to activate a remote memory acquired during its exploratory orientation flights, we conclude that non-lethal doses of the three neonicotinoids tested either block the retrieval of exploratory navigation memory or alter this form of navigation memory. These findings are discussed in the context of the application of neonicotinoids in plant protection. PMID:24646521

A worldwide survey of genome sequence variation provides insight into the evolutionary history of the honeybee Apis mellifera.

PubMed

Wallberg, Andreas; Han, Fan; Wellhagen, Gustaf; Dahle, Bjørn; Kawata, Masakado; Haddad, Nizar; Simões, Zilá Luz Paulino; Allsopp, Mike H; Kandemir, Irfan; De la Rúa, Pilar; Pirk, Christian W; Webster, Matthew T

2014-10-01

The honeybee Apis mellifera has major ecological and economic importance. We analyze patterns of genetic variation at 8.3 million SNPs, identified by sequencing 140 honeybee genomes from a worldwide sample of 14 populations at a combined total depth of 634×. These data provide insight into the evolutionary history and genetic basis of local adaptation in this species. We find evidence that population sizes have fluctuated greatly, mirroring historical fluctuations in climate, although contemporary populations have high genetic diversity, indicating the absence of domestication bottlenecks. Levels of genetic variation are strongly shaped by natural selection and are highly correlated with patterns of gene expression and DNA methylation. We identify genomic signatures of local adaptation, which are enriched in genes expressed in workers and in immune system- and sperm motility-related genes that might underlie geographic variation in reproduction, dispersal and disease resistance. This study provides a framework for future investigations into responses to pathogens and climate change in honeybees.

Controlling the impact of the managed honeybee on wild bees in protected areas.

PubMed

Henry, Mickaël; Rodet, Guy

2018-06-18

In recent years, conservation biologists have raised awareness about the risk of ecological interference between massively introduced managed honeybees and the native wild bee fauna in protected natural areas. In this study, we surveyed wild bees and quantified their nectar and pollen foraging success in a rosemary Mediterranean scrubland in southern France, under different conditions of apiary size and proximity. We found that high-density beekeeping triggers foraging competition which depresses not only the occurrence (-55%) and nectar foraging success (-50%) of local wild bees but also nectar (-44%) and pollen (-36%) harvesting by the honeybees themselves. Overall, those competition effects spanned distances of 600-1.100 m around apiaries, i.e. covering 1.1-3.8km 2 areas. Regardless the considered competition criterion, setting distance thresholds among apiaries appeared more tractable than setting colony density thresholds for beekeeping regulation. Moreover, the intraspecific competition among the honeybees has practical implications for beekeepers. It shows that the local carrying capacity has been exceeded and raises concerns for honey yields and colony sustainability. It also offers an effective ecological criterion for pragmatic decision-making whenever conservation practitioners envision progressively reducing beekeeping in protected areas. Although specific to the studied area, the recommendations provided here may help raise consciousness about the threat high-density beekeeping may pose to local nature conservation initiatives, especially in areas with sensitive or endangered plant or bee species such as small oceanic islands with high levels of endemism.

Optimisation of a honeybee-colony's energetics via social learning based on queuing delays

NASA Astrophysics Data System (ADS)

Thenius, Ronald; Schmickl, Thomas; Crailsheim, Karl

2008-06-01

Natural selection shaped the foraging-related processes of honeybees in such a way that a colony can react to changing environmental conditions optimally. To investigate this complex dynamic social system, we developed a multi-agent model of the nectar flow inside and outside of a honeybee colony. In a honeybee colony, a temporal caste collects nectar in the environment. These foragers bring their harvest into the colony, where they unload their nectar loads to one or more storer bees. Our model predicts that a cohort of foragers, collecting nectar from a single nectar source, is able to detect changes in quality in other food sources they have never visited, via the nectar processing system of the colony. We identified two novel pathways of forager-to-forager communication. Foragers can gain information about changes in the nectar flow in the environment via changes in their mean waiting time for unloadings and the number of experienced multiple unloadings. This way two distinct groups of foragers that forage on different nectar sources and that never communicate directly can share information via a third cohort of worker bees. We show that this noisy and loosely knotted social network allows a colony to perform collective information processing, so that a single forager has all necessary information available to be able to 'tune' its social behaviour, like dancing or dance-following. This way the net nectar gain of the colony is increased.

Reversible switching between epigenetic states in honeybee behavioral subcastes

PubMed Central

Herb, Brian R.; Wolschin, Florian; Hansen, Kasper D.; Aryee, Martin J.; Langmead, Ben; Irizarry, Rafael; Amdam, Gro V.; Feinberg, Andrew P.

2012-01-01

In honeybee societies, distinct caste phenotypes are created from the same genotype, suggesting a role for epigenetics in deriving these behaviorally different phenotypes. We found no differences in DNA methylation between irreversible worker/queen castes, but substantial differences between nurses and forager subcastes. Reverting foragers back to nurses reestablished methylation levels for a majority of genes and provided the first evidence in any organism of reversible epigenetic changes associated with behavior. PMID:22983211

Consumption rate of some proteinic diets affecting hypopharyngeal glands development in honeybee workers

PubMed Central

Al-Ghamdi, Ahmad AlKazim; Al-Khaibari, Abeer M.; Omar, Mohamed O.

2010-01-01

The experiment was carried out under laboratory condition to study the consumption of some proteinic diets and their effect on hypopharyngeal glands (HPG) development during nursing period. The results showed that the bee bread and the pollen loads mixture with sugar (1:1) were more consumed by honeybee workers followed by Nectapol® and Yeast-Gluten mixture. The lowest consumption amount was recorded with traditional substitute. Clear differences were found in HPG development under feeding with different diets. The maximum development degree was observed when fed with bee bread followed by pollen loads and mixture from Yeast, Gluten and sugar (1:1:2). The acinal surface of HPG showed clear difference under feeding with difference diets. The largest area was recorded when honeybee workers fed on bee bread followed by Yeast-Gluten-sugar mixture (diet,4) and pollen loads(diet,2). PMID:23961106

Giant honeybees ( Apis dorsata) mob wasps away from the nest by directed visual patterns

NASA Astrophysics Data System (ADS)

Kastberger, Gerald; Weihmann, Frank; Zierler, Martina; Hötzl, Thomas

2014-11-01

The open nesting behaviour of giant honeybees ( Apis dorsata) accounts for the evolution of a series of defence strategies to protect the colonies from predation. In particular, the concerted action of shimmering behaviour is known to effectively confuse and repel predators. In shimmering, bees on the nest surface flip their abdomens in a highly coordinated manner to generate Mexican wave-like patterns. The paper documents a further-going capacity of this kind of collective defence: the visual patterns of shimmering waves align regarding their directional characteristics with the projected flight manoeuvres of the wasps when preying in front of the bees' nest. The honeybees take here advantage of a threefold asymmetry intrinsic to the prey-predator interaction: (a) the visual patterns of shimmering turn faster than the wasps on their flight path, (b) they "follow" the wasps more persistently (up to 100 ms) than the wasps "follow" the shimmering patterns (up to 40 ms) and (c) the shimmering patterns align with the wasps' flight in all directions at the same strength, whereas the wasps have some preference for horizontal correspondence. The findings give evidence that shimmering honeybees utilize directional alignment to enforce their repelling power against preying wasps. This phenomenon can be identified as predator driving which is generally associated with mobbing behaviour (particularly known in selfish herds of vertebrate species), which is, until now, not reported in insects.

Honeybee Venom Proteome Profile of Queens and Winter Bees as Determined by a Mass Spectrometric Approach

PubMed Central

Danneels, Ellen L.; Van Vaerenbergh, Matthias; Debyser, Griet; Devreese, Bart; de Graaf, Dirk C.

2015-01-01

Venoms of invertebrates contain an enormous diversity of proteins, peptides, and other classes of substances. Insect venoms are characterized by a large interspecific variation resulting in extended lists of venom compounds. The venom composition of several hymenopterans also shows different intraspecific variation. For instance, venom from different honeybee castes, more specifically queens and workers, shows quantitative and qualitative variation, while the environment, like seasonal changes, also proves to be an important factor. The present study aimed at an in-depth analysis of the intraspecific variation in the honeybee venom proteome. In summer workers, the recent list of venom proteins resulted from merging combinatorial peptide ligand library sample pretreatment and targeted tandem mass spectrometry realized with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS/MS). Now, the same technique was used to determine the venom proteome of queens and winter bees, enabling us to compare it with that of summer bees. In total, 34 putative venom toxins were found, of which two were never described in honeybee venoms before. Venom from winter workers did not contain toxins that were not present in queens or summer workers, while winter worker venom lacked the allergen Api m 12, also known as vitellogenin. Venom from queen bees, on the other hand, was lacking six of the 34 venom toxins compared to worker bees, while it contained two new venom toxins, in particularly serine proteinase stubble and antithrombin-III. Although people are hardly stung by honeybees during winter or by queen bees, these newly identified toxins should be taken into account in the characterization of a putative allergic response against Apis mellifera stings. PMID:26529016

Honeybees as a model for the study of visually guided flight, navigation, and biologically inspired robotics.

PubMed

Srinivasan, Mandyam V

2011-04-01

Research over the past century has revealed the impressive capacities of the honeybee, Apis mellifera, in relation to visual perception, flight guidance, navigation, and learning and memory. These observations, coupled with the relative ease with which these creatures can be trained, and the relative simplicity of their nervous systems, have made honeybees an attractive model in which to pursue general principles of sensorimotor function in a variety of contexts, many of which pertain not just to honeybees, but several other animal species, including humans. This review begins by describing the principles of visual guidance that underlie perception of the world in three dimensions, obstacle avoidance, control of flight speed, and orchestrating smooth landings. We then consider how navigation over long distances is accomplished, with particular reference to how bees use information from the celestial compass to determine their flight bearing, and information from the movement of the environment in their eyes to gauge how far they have flown. Finally, we illustrate how some of the principles gleaned from these studies are now being used to design novel, biologically inspired algorithms for the guidance of unmanned aerial vehicles.

Detection of Methyl Salicylate Transforted by Honeybees (Apis mellifera) Using Solid Phase Microextration (SPME) Fibers

DOE Office of Scientific and Technical Information (OSTI.GOV)

BENDER, SUSAN FAE ANN; RODACY, PHILIP J.; BARNETT, JAMES L.

The ultimate goal of many environmental measurements is to determine the risk posed to humans or ecosystems by various contaminants. Conventional environmental monitoring typically requires extensive sampling grids covering several media including air, water, soil and vegetation. A far more efficient, innovative and inexpensive tactic has been found using honeybees as sampling mechanisms. Members from a single bee colony forage over large areas ({approx}2 x 10{sup 6} m{sup 2}), making tens of thousands of trips per day, and return to a fixed location where sampling can be conveniently conducted. The bees are in direct contact with the air, water, soilmore » and vegetation where they encounter and collect any contaminants that are present in gaseous, liquid and particulate form. The monitoring of honeybees when they return to the hive provides a rapid method to assess chemical distributions and impacts (1). The primary goal of this technology is to evaluate the efficiency of the transport mechanism (honeybees) to the hive using preconcentrators to collect samples. Once the extent and nature of the contaminant exposure has been characterized, resources can be distributed and environmental monitoring designs efficiently directed to the most appropriate locations. Methyl salicylate, a chemical agent surrogate was used as the target compound in this study.« less

Antennal proteome comparison of sexually mature drone and forager honeybees.

PubMed

Feng, Mao; Song, Feifei; Aleku, Dereje Woltedji; Han, Bin; Fang, Yu; Li, Jianke

2011-07-01

Honeybees have evolved an intricate system of chemical communication to regulate their complex social interactions. Specific proteins involved in odorant detection most likely supported this chemical communication. Odorant reception takes place mainly in the antennae within hairlike structures called olfactory sensilla. Antennal proteomes of sexually mature drone and forager worker bees (an age group of bees assigned to perform field tasks) were compared using two-dimensional electrophoresis, mass spectrometry, quantitative real-time polymerase chain reaction, and bioinformatics. Sixty-one differentially expressed proteins were identified in which 67% were highly upregulated in the drones' antennae whereas only 33% upregulated in the worker bees' antennae. The antennae of the worker bees strongly expressed carbohydrate and energy metabolism and molecular transporters signifying a strong demand for metabolic energy and odorant binding proteins for their foraging activities and other olfactory responses, while proteins related to fatty acid metabolism, antioxidation, and protein folding were strongly upregulated in the drones' antennae as an indication of the importance for the detection and degradation of sex pheromones during queen identification for mating. On the basis of both groups of altered antenna proteins, carbohydrate metabolism and energy production and molecular transporters comprised more than 80% of the functional enrichment analysis and 45% of the constructed biological interaction networks (BIN), respectively. This suggests these two protein families play crucial roles in the antennal olfactory function of sexually mature drone and forager worker bees. Several key node proteins in the BIN were validated at the transcript level. This first global proteomic comparative analysis of antennae reveals sex-biased protein expression in both bees, indicating that odorant response mechanisms are sex-specific because of natural selection for different olfactory

What is the main driver of ageing in long-lived winter honeybees: antioxidant enzymes, innate immunity, or vitellogenin?

PubMed

Aurori, Cristian M; Buttstedt, Anja; Dezmirean, Daniel S; Mărghitaş, Liviu A; Moritz, Robin F A; Erler, Silvio

2014-06-01

To date five different theories compete in explaining the biological mechanisms of senescence or ageing in invertebrates. Physiological, genetical, and environmental mechanisms form the image of ageing in individuals and groups. Social insects, especially the honeybee Apis mellifera, present exceptional model systems to study developmentally related ageing. The extremely high phenotypic plasticity for life expectancy resulting from the female caste system provides a most useful system to study open questions with respect to ageing. Here, we used long-lived winter worker honeybees and measured transcriptional changes of 14 antioxidative enzyme, immunity, and ageing-related (insulin/insulin-like growth factor signaling pathway) genes at two time points during hibernation. Additionally, worker bees were challenged with a bacterial infection to test ageing- and infection-associated immunity changes. Gene expression levels for each group of target genes revealed that ageing had a much higher impact than the bacterial challenge, notably for immunity-related genes. Antimicrobial peptide and antioxidative enzyme genes were significantly upregulated in aged worker honeybees independent of bacterial infections. The known ageing markers vitellogenin and IlP-1 were opposed regulated with decreasing vitellogenin levels during ageing. The increased antioxidative enzyme and antimicrobial peptide gene expression may contribute to a retardation of senescence in long-lived hibernating worker honeybees. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Differences in heat sensitivity between Japanese honeybees and hornets under high carbon dioxide and humidity conditions inside bee balls.

PubMed

Sugahara, Michio; Nishimura, Yasuichiro; Sakamoto, Fumio

2012-01-01

Upon capture in a bee ball (i.e., a dense cluster of Japanese honeybees forms in response to a predatory attack), an Asian giant hornet causes a rapid increase in temperature, carbon dioxide (CO₂), and humidity. Within five min after capture, the temperature reaches 46°C, and the CO₂ concentration reaches 4%. Relative humidity gradually rises to 90% or above in 3 to 4 min. The hornet dies within 10 min of its capture in the bee ball. To investigate the effect of temperature, CO₂, and humidity on hornet mortality, we determined the lethal temperature of hornets exposed for 10 min to different humidity and CO₂/O₂ (oxygen) levels. In expiratory air (3.7% CO₂), the lethal temperature was ≥ 2° lower than that in normal air. The four hornet species used in this experiment died at 44-46°C under these conditions. Hornet death at low temperatures results from an increase in CO₂ level in bee balls. Japanese honeybees generate heat by intense respiration, as an overwintering strategy, which produces a high CO₂ and humidity environment and maintains a tighter bee ball. European honeybees are usually killed in the habitat of hornets. In contrast, Japanese honeybees kill hornets without sacrificing themselves by using heat and respiration by-products and forming tight bee balls.

A Three-Dimensional Atlas of the Honeybee Neck

PubMed Central

Berry, Richard P.; Ibbotson, Michael R.

2010-01-01

Three-dimensional digital atlases are rapidly becoming indispensible in modern biology. We used serial sectioning combined with manual registration and segmentation of images to develop a comprehensive and detailed three-dimensional atlas of the honeybee head-neck system. This interactive atlas includes skeletal structures of the head and prothorax, the neck musculature, and the nervous system. The scope and resolution of the model exceeds atlases previously developed on similar sized animals, and the interactive nature of the model provides a far more accessible means of interpreting and comprehending insect anatomy and neuroanatomy. PMID:20520729

Honeybee nutrition is linked to landscape composition

PubMed Central

Donkersley, Philip; Rhodes, Glenn; Pickup, Roger W; Jones, Kevin C; Wilson, Kenneth

2014-01-01

Declines in insect pollinators in Europe have been linked to changes in land use. Pollinator nutrition is dependent on floral resources (i.e., nectar and pollen), which are linked to landscape composition. Here, we present a stratified analysis of the nutritional composition of beebread in managed honeybee hives with a view to examining potential sources of variation in its nutritional composition. Specifically, we tested the hypothesis that beebread composition correlates with local land use and therefore available floral resources. The results demonstrated that the starch, lipid, and moisture contents of beebread are all highly conserved across hives, whereas levels of protein and nonreducing sugar increased as the year progressed, reducing sugars, however, decreased during the first half of the year and then increased toward the end. Local land use around hives was quantified using data from the Countryside Survey 2007 Land Cover Map. Bee-bread protein content was negatively correlated with increasing levels of arable and horticultural farmland surrounding hives and positively correlated with the cover of natural grasslands and broadleaf woodlands. Reducing sugar content was also positively correlated with the amount of broad-leaved woodland in a 3 Km² radius from the hives. Previous studies on a range of invertebrates, including honeybees, indicate that dietary protein intake may have a major impact on correlates of fitness, including longevity and immune function. The finding that beebread protein content correlates with land use suggests that landscape composition may impact on insect pollinator well-being and provides a link between landscape and the nutritional ecology of socially foraging insects in a way not previously considered. PMID:25505544

A critical number of workers in a honeybee colony triggers investment in reproduction

NASA Astrophysics Data System (ADS)

Smith, Michael L.; Ostwald, Madeleine M.; Loftus, J. Carter; Seeley, Thomas D.

2014-10-01

Social insect colonies, like individual organisms, must decide as they develop how to allocate optimally their resources among survival, growth, and reproduction. Only when colonies reach a certain state do they switch from investing purely in survival and growth to investing also in reproduction. But how do worker bees within a colony detect that their colony has reached the state where it is adaptive to begin investing in reproduction? Previous work has shown that larger honeybee colonies invest more in reproduction (i.e., the production of drones and queens), however, the term `larger' encompasses multiple colony parameters including number of adult workers, size of the nest, amount of brood, and size of the honey stores. These colony parameters were independently increased in this study to test which one(s) would increase a colony's investment in reproduction via males. This was assayed by measuring the construction of drone comb, the special type of comb in which drones are reared. Only an increase in the number of workers stimulated construction of drone comb. Colonies with over 4,000 workers began building drone comb, independent of the other colony parameters. These results show that attaining a critical number of workers is the key parameter for honeybee colonies to start to shift resources towards reproduction. These findings are relevant to other social systems in which a group's members must adjust their behavior as a function of the group's size.

Effect of 1,3-1,6 β-Glucan on Natural and Experimental Deformed Wing Virus Infection in Newly Emerged Honeybees (Apis mellifera ligustica)

PubMed Central

Sagona, Simona; Carrozza, Maria Luisa; Forzan, Mario; Pizzurro, Federica; Bibbiani, Carlo; Miragliotta, Vincenzo; Abramo, Francesca; Millanta, Francesca; Bagliacca, Marco; Poli, Alessandro; Felicioli, Antonio

2016-01-01

The Western Honeybee is a key pollinator for natural as well as agricultural ecosystems. In the last decade massive honeybee colony losses have been observed worldwide, the result of a complex syndrome triggered by multiple stress factors, with the RNA virus Deformed Wing Virus (DWV) and the mite Varroa destructor playing crucial roles. The mite supports replication of DWV to high titers, which exert an immunosuppressive action and correlate with the onset of the disease. The aim of this study was to investigate the effect of 1,3–1,6 β-glucan, a natural innate immune system modulator, on honeybee response to low-titer natural and high-titer experimental DWV infection. As the effects exerted by ß-glucans can be remarkably different, depending on the target organism and the dose administered, two parallel experiments were performed, where 1,3–1,6 ß-glucan at a concentration of 0.5% and 2% respectively, was added to the diet of three cohorts of newly emerged honeybees, which were sampled from a Varroa-free apiary and harboured a low endogenous DWV viral titer. Each cohort was subjected to one of the following experimental treatments: no injection, injection of a high-copy number DWV suspension into the haemocel (experimental DWV infection) or injection of PBS into the haemocoel (physical injury). Control bees fed a ß-glucan-free diet were subjected to the same treatments. Viral load, survival rate, haemocyte populations and phenoloxidase activity of each experimental group were measured and compared. The results indicated that oral administration of 0.5% ß-glucan to naturally infected honeybees was associated with a significantly decrease of the number of infected bees and viral load they carried, and with a significant increase of the survival rate, suggesting that this natural immune modulator molecule might contribute to increase honeybee resistance to viral infection. PMID:27829027

Viability of honeybee colonies exposed to sunflowers grown from seeds treated with the neonicotinoids thiamethoxam and clothianidin.

PubMed

Hernando, M Dolores; Gámiz, Victoria; Gil-Lebrero, Sergio; Rodríguez, Inmaculada; García-Valcárcel, Ana I; Cutillas, V; Fernández-Alba, Amadeo R; Flores, José M

2018-07-01

In this study, honeybee colonies were monitored in a field study conducted on sunflowers grown from seeds treated with the systemic neonicotinoids thiamethoxam or clothianidin. This field trial was carried out in different representative growing areas in Spain over a beekeeping season. The health and development of the colonies was assessed by measuring factors that have a significant influence on their strength and overwintering ability. The parameters assessed were: colony strength (adult bees), brood development, amount of pollen and honey stores and presence and status of the queen. The concentration of residues (clothianidin and thiamethoxam) in samples of beebread and in adult bees was at the level of ng.g -1 ; in the ranges of 0.10-2.89 ng g -1 and 0.05-0.12 ng g -1 ; 0.10-0.37 ng g -1 and 0.01-0.05 ng g -1 , respectively. Multivariate models were applied to evaluate the interaction among factors. No significant differences were found between the honeybee colonies of the different treatment groups, either exposed or not to the neonicotinoids. The seasonal development of the colonies was affected by the environmental conditions which, together with the initial strength of the bee colonies and the characteristics of the plots, had a significant effect on the different variables studied. Copyright © 2018 Elsevier Ltd. All rights reserved.

Spontaneous Recovery After Extinction of the Conditioned Proboscis Extension Response in the Honeybee

PubMed Central

Sandoz, Jean-Christophe; Pham-Delègue, Minh-Hà

2004-01-01

In honeybees, the proboscis extension response (PER) can be conditioned by associating an odor stimulus (CS) to a sucrose reward (US). Conditioned responses to the CS, which are acquired by most bees after a single CS-US pairing, disappear after repeated unrewarded presentations of the CS, a process called extinction. Extinction is usually thought to be based either on (1) the disruption of the stored CS-US association, or (2) the formation of an inhibitory “CS-no US” association that is better retrieved than the initial CS-US association. The observation of spontaneous recovery, i.e., the reappearance of responses to the CS after time passes following extinction, is traditionally interpreted as a proof for the formation of a transient inhibitory association. To provide a better understanding of extinction in honeybees, we examined whether time intervals during training and extinction or the number of conditioning and extinction trials have an effect on the occurrence of spontaneous recovery. We found that spontaneous recovery mostly occurs when conditioning and testing took place in a massed fashion (1-min intertrial intervals). Moreover, spontaneous recovery depended on the time elapsed since extinction, 1 h being an optimum. Increasing the number of conditioning trials improved the spontaneous recovery level, whereas increasing the number of extinction trials reduced it. Lastly, we show that after single-trial conditioning, spontaneous recovery appears only once after extinction. These elements suggest that in honeybees extinction of the PER actually reflects the impairment of the CS-US association, but that depending on training parameters different memory substrates are affected. PMID:15466313

Honeybees in a virtual reality environment learn unique combinations of colour and shape.

PubMed

Rusch, Claire; Roth, Eatai; Vinauger, Clément; Riffell, Jeffrey A

2017-10-01

Honeybees are well-known models for the study of visual learning and memory. Whereas most of our knowledge of learned responses comes from experiments using free-flying bees, a tethered preparation would allow fine-scale control of the visual stimuli as well as accurate characterization of the learned responses. Unfortunately, conditioning procedures using visual stimuli in tethered bees have been limited in their efficacy. In this study, using a novel virtual reality environment and a differential training protocol in tethered walking bees, we show that the majority of honeybees learn visual stimuli, and need only six paired training trials to learn the stimulus. We found that bees readily learn visual stimuli that differ in both shape and colour. However, bees learn certain components over others (colour versus shape), and visual stimuli are learned in a non-additive manner with the interaction of specific colour and shape combinations being crucial for learned responses. To better understand which components of the visual stimuli the bees learned, the shape-colour association of the stimuli was reversed either during or after training. Results showed that maintaining the visual stimuli in training and testing phases was necessary to elicit visual learning, suggesting that bees learn multiple components of the visual stimuli. Together, our results demonstrate a protocol for visual learning in restrained bees that provides a powerful tool for understanding how components of a visual stimulus elicit learned responses as well as elucidating how visual information is processed in the honeybee brain. © 2017. Published by The Company of Biologists Ltd.

Does Fine Color Discrimination Learning in Free-Flying Honeybees Change Mushroom-Body Calyx Neuroarchitecture?

PubMed

Sommerlandt, Frank M J; Spaethe, Johannes; Rössler, Wolfgang; Dyer, Adrian G

2016-01-01

Honeybees learn color information of rewarding flowers and recall these memories in future decisions. For fine color discrimination, bees require differential conditioning with a concurrent presentation of target and distractor stimuli to form a long-term memory. Here we investigated whether the long-term storage of color information shapes the neural network of microglomeruli in the mushroom body calyces and if this depends on the type of conditioning. Free-flying honeybees were individually trained to a pair of perceptually similar colors in either absolute conditioning towards one of the colors or in differential conditioning with both colors. Subsequently, bees of either conditioning groups were tested in non-rewarded discrimination tests with the two colors. Only bees trained with differential conditioning preferred the previously learned color, whereas bees of the absolute conditioning group, and a stimuli-naïve group, chose randomly among color stimuli. All bees were then kept individually for three days in the dark to allow for complete long-term memory formation. Whole-mount immunostaining was subsequently used to quantify variation of microglomeruli number and density in the mushroom-body lip and collar. We found no significant differences among groups in neuropil volumes and total microglomeruli numbers, but learning performance was negatively correlated with microglomeruli density in the absolute conditioning group. Based on these findings we aim to promote future research approaches combining behaviorally relevant color learning tests in honeybees under free-flight conditions with neuroimaging analysis; we also discuss possible limitations of this approach.

A Locomotor Deficit Induced by Sublethal Doses of Pyrethroid and Neonicotinoid Insecticides in the Honeybee Apis mellifera.

PubMed

Charreton, Mercédès; Decourtye, Axel; Henry, Mickaël; Rodet, Guy; Sandoz, Jean-Christophe; Charnet, Pierre; Collet, Claude

2015-01-01

The toxicity of pesticides used in agriculture towards non-targeted organisms and especially pollinators has recently drawn the attention from a broad scientific community. Increased honeybee mortality observed worldwide certainly contributes to this interest. The potential role of several neurotoxic insecticides in triggering or potentiating honeybee mortality was considered, in particular phenylpyrazoles and neonicotinoids, given that they are widely used and highly toxic for insects. Along with their ability to kill insects at lethal doses, they can compromise survival at sublethal doses by producing subtle deleterious effects. In this study, we compared the bee's locomotor ability, which is crucial for many tasks within the hive (e.g. cleaning brood cells, feeding larvae…), before and after an acute sublethal exposure to one insecticide belonging to the two insecticide classes, fipronil and thiamethoxam. Additionally, we examined the locomotor ability after exposure to pyrethroids, an older chemical insecticide class still widely used and known to be highly toxic to bees as well. Our study focused on young bees (day 1 after emergence) since (i) few studies are available on locomotion at this stage and (ii) in recent years, pesticides have been reported to accumulate in different hive matrices, where young bees undergo their early development. At sublethal doses (SLD48h, i.e. causing no mortality at 48 h), three pyrethroids, namely cypermethrin (2.5 ng/bee), tetramethrin (70 ng/bee), tau-fluvalinate (33 ng/bee) and the neonicotinoid thiamethoxam (3.8 ng/bee) caused a locomotor deficit in honeybees. While the SLD48h of fipronil (a phenylpyrazole, 0.5 ng/bee) had no measurable effect on locomotion, we observed high mortality several days after exposure, an effect that was not observed with the other insecticides. Although locomotor deficits observed in the sublethal range of pyrethroids and thiamethoxam would suggest deleterious effects in the field, the case of

A Locomotor Deficit Induced by Sublethal Doses of Pyrethroid and Neonicotinoid Insecticides in the Honeybee Apis mellifera

PubMed Central

Charreton, Mercédès; Decourtye, Axel; Henry, Mickaël; Rodet, Guy; Sandoz, Jean-Christophe; Charnet, Pierre; Collet, Claude

2015-01-01

The toxicity of pesticides used in agriculture towards non-targeted organisms and especially pollinators has recently drawn the attention from a broad scientific community. Increased honeybee mortality observed worldwide certainly contributes to this interest. The potential role of several neurotoxic insecticides in triggering or potentiating honeybee mortality was considered, in particular phenylpyrazoles and neonicotinoids, given that they are widely used and highly toxic for insects. Along with their ability to kill insects at lethal doses, they can compromise survival at sublethal doses by producing subtle deleterious effects. In this study, we compared the bee’s locomotor ability, which is crucial for many tasks within the hive (e.g. cleaning brood cells, feeding larvae…), before and after an acute sublethal exposure to one insecticide belonging to the two insecticide classes, fipronil and thiamethoxam. Additionally, we examined the locomotor ability after exposure to pyrethroids, an older chemical insecticide class still widely used and known to be highly toxic to bees as well. Our study focused on young bees (day 1 after emergence) since (i) few studies are available on locomotion at this stage and (ii) in recent years, pesticides have been reported to accumulate in different hive matrices, where young bees undergo their early development. At sublethal doses (SLD48h, i.e. causing no mortality at 48h), three pyrethroids, namely cypermethrin (2.5 ng/bee), tetramethrin (70 ng/bee), tau-fluvalinate (33 ng/bee) and the neonicotinoid thiamethoxam (3.8 ng/bee) caused a locomotor deficit in honeybees. While the SLD48h of fipronil (a phenylpyrazole, 0.5 ng/bee) had no measurable effect on locomotion, we observed high mortality several days after exposure, an effect that was not observed with the other insecticides. Although locomotor deficits observed in the sublethal range of pyrethroids and thiamethoxam would suggest deleterious effects in the field, the case

Whole-genome resequencing of honeybee drones to detect genomic selection in a population managed for royal jelly.

PubMed

Wragg, David; Marti-Marimon, Maria; Basso, Benjamin; Bidanel, Jean-Pierre; Labarthe, Emmanuelle; Bouchez, Olivier; Le Conte, Yves; Vignal, Alain

2016-06-03

Four main evolutionary lineages of A. mellifera have been described including eastern Europe (C) and western and northern Europe (M). Many apiculturists prefer bees from the C lineage due to their docility and high productivity. In France, the routine importation of bees from the C lineage has resulted in the widespread admixture of bees from the M lineage. The haplodiploid nature of the honeybee Apis mellifera, and its small genome size, permits affordable and extensive genomics studies. As a pilot study of a larger project to characterise French honeybee populations, we sequenced 60 drones sampled from two commercial populations managed for the production of honey and royal jelly. Results indicate a C lineage origin, whilst mitochondrial analysis suggests two drones originated from the O lineage. Analysis of heterozygous SNPs identified potential copy number variants near to genes encoding odorant binding proteins and several cytochrome P450 genes. Signatures of selection were detected using the hapFLK haplotype-based method, revealing several regions under putative selection for royal jelly production. The framework developed during this study will be applied to a broader sampling regime, allowing the genetic diversity of French honeybees to be characterised in detail.

Whole-genome resequencing of honeybee drones to detect genomic selection in a population managed for royal jelly

PubMed Central

Wragg, David; Marti-Marimon, Maria; Basso, Benjamin; Bidanel, Jean-Pierre; Labarthe, Emmanuelle; Bouchez, Olivier; Le Conte, Yves; Vignal, Alain

2016-01-01

Four main evolutionary lineages of A. mellifera have been described including eastern Europe (C) and western and northern Europe (M). Many apiculturists prefer bees from the C lineage due to their docility and high productivity. In France, the routine importation of bees from the C lineage has resulted in the widespread admixture of bees from the M lineage. The haplodiploid nature of the honeybee Apis mellifera, and its small genome size, permits affordable and extensive genomics studies. As a pilot study of a larger project to characterise French honeybee populations, we sequenced 60 drones sampled from two commercial populations managed for the production of honey and royal jelly. Results indicate a C lineage origin, whilst mitochondrial analysis suggests two drones originated from the O lineage. Analysis of heterozygous SNPs identified potential copy number variants near to genes encoding odorant binding proteins and several cytochrome P450 genes. Signatures of selection were detected using the hapFLK haplotype-based method, revealing several regions under putative selection for royal jelly production. The framework developed during this study will be applied to a broader sampling regime, allowing the genetic diversity of French honeybees to be characterised in detail. PMID:27255426

CaMKII knockdown affects both early and late phases of olfactory long-term memory in the honeybee.

PubMed

Scholl, Christina; Kübert, Natalie; Muenz, Thomas S; Rössler, Wolfgang

2015-12-01

Honeybees are able to solve complex learning tasks and memorize learned information for long time periods. The molecular mechanisms mediating long-term memory (LTM) in the honeybee Apis mellifera are, to a large part, still unknown. We approached this question by investigating the potential function of the calcium/calmodulin-dependent protein kinase II (CaMKII), an enzyme known as a 'molecular memory switch' in vertebrates. CaMKII is able to switch to a calcium-independent constitutively active state, providing a mechanism for a molecular memory and has further been shown to play an essential role in structural synaptic plasticity. Using a combination of knockdown by RNA interference and pharmacological manipulation, we disrupted the function of CaMKII during olfactory learning and memory formation. We found that learning, memory acquisition and mid-term memory were not affected, but all manipulations consistently resulted in an impaired LTM. Both early LTM (24 h after learning) and late LTM (72 h after learning) were significantly disrupted, indicating the necessity of CaMKII in two successive stages of LTM formation in the honeybee. © 2015. Published by The Company of Biologists Ltd.

RNA-sequence analysis of gene expression from honeybees (Apis mellifera) infected with Nosema ceranae

PubMed Central

Fougeroux, André; Petit, Fabien; Anselmo, Anna; Gorni, Chiara; Cucurachi, Marco; Cersini, Antonella; Granato, Anna; Cardeti, Giusy; Formato, Giovanni; Mutinelli, Franco; Giuffra, Elisabetta; Williams, John L.; Botti, Sara

2017-01-01

Honeybees (Apis mellifera) are constantly subjected to many biotic stressors including parasites. This study examined honeybees infected with Nosema ceranae (N. ceranae). N. ceranae infection increases the bees energy requirements and may contribute to their decreased survival. RNA-seq was used to investigate gene expression at days 5, 10 and 15 Post Infection (P.I) with N. ceranae. The expression levels of genes, isoforms, alternative transcription start sites (TSS) and differential promoter usage revealed a complex pattern of transcriptional and post-transcriptional gene regulation suggesting that bees use a range of tactics to cope with the stress of N. ceranae infection. N. ceranae infection may cause reduced immune function in the bees by: (i)disturbing the host amino acids metabolism (ii) down-regulating expression of antimicrobial peptides (iii) down-regulation of cuticle coatings and (iv) down-regulation of odorant binding proteins. PMID:28350872

Complex memories in honeybees: can there be more than two?

PubMed

Reinhard, Judith; Srinivasan, Mandyam V; Zhang, Shaowu

2006-04-01

Foraging honeybees are likely to learn visual and chemical cues associated with many different food sources. Here, we explore how many such sources can be memorized and recalled. Marked bees were trained to visit two (or three) sugar feeders, each placed at a different outdoor location and carrying a different scent. We then tested the ability of the bees to recall these locations and fly to them, when the training scents were blown into the hive, and the scents and food at the feeders were removed. When trained on two feeder locations, each associated with a different scent, the bees could correctly recall the location associated with each scent. However, this ability broke down when the number of scents and feeder locations was increased to three. Performance was partially restored when each of the three training feeders was endowed with an additional cue, namely, a distinct colour. Our results suggest that bees can recall a maximum of two locations when each is associated with a different scent. However, this number can be increased if the scent cues are augmented by visual cues. These findings have implications for the ways in which associations are established and laid down in honeybee memory.

Neural basis of forward flight control and landing in honeybees.

PubMed

Ibbotson, M R; Hung, Y-S; Meffin, H; Boeddeker, N; Srinivasan, M V

2017-11-06

The impressive repertoire of honeybee visually guided behaviors, and their ability to learn has made them an important tool for elucidating the visual basis of behavior. Like other insects, bees perform optomotor course correction to optic flow, a response that is dependent on the spatial structure of the visual environment. However, bees can also distinguish the speed of image motion during forward flight and landing, as well as estimate flight distances (odometry), irrespective of the visual scene. The neural pathways underlying these abilities are unknown. Here we report on a cluster of descending neurons (DNIIIs) that are shown to have the directional tuning properties necessary for detecting image motion during forward flight and landing on vertical surfaces. They have stable firing rates during prolonged periods of stimulation and respond to a wide range of image speeds, making them suitable to detect image flow during flight behaviors. While their responses are not strictly speed tuned, the shape and amplitudes of their speed tuning functions are resistant to large changes in spatial frequency. These cells are prime candidates not only for the control of flight speed and landing, but also the basis of a neural 'front end' of the honeybee's visual odometer.

Selective Behaviour of Honeybees in Acquiring European Propolis Plant Precursors.

PubMed

Isidorov, Valery A; Bakier, Sławomir; Pirożnikow, Ewa; Zambrzycka, Monika; Swiecicka, Izabela

2016-06-01

Honey bees harvest resins from various plant species and use them in the hive as propolis. While there have been a number of studies concerning the chemical composition of this antimicrobial product, little is known about selective behavior and bee preference when different potential plant sources of resin are available. The main objective of this paper was to investigate some aspects of behavioral patterns of honeybees in the context of resin acquisition. Samples of propolis originating from temperate zones of Europe and the supposed botanical precursors of the product were analyzed. Taxonomical markers of bud resins of two white birch species, aspen, black poplar, horse-chestnut, black alder, and Scots pine were determined through GC-MS analysis. All these trees have been reported as sources of propolis, but comparisons of the chemical composition of their bud resins with the compositions of propolis samples from seven European countries have demonstrated the presence of taxonomical markers only from black poplar, aspen, and one species of birch. This suggests selective behavior during the collection of bud resins by honeybees. To examine the causes of such selectivity, the antimicrobial properties of bud resins were determined. Horse-chestnut resins had lower antimicrobial activity than the other resins which did not differ significantly.

Bigger is better: honeybee colonies as distributed information-gathering systems.

PubMed

Donaldson-Matasci, Matina C; DeGrandi-Hoffman, Gloria; Dornhaus, Anna

2013-03-01

In collectively foraging groups, communication about food resources can play an important role in the organization of the group's activity. For example, the honeybee dance communication system allows colonies to selectively allocate foragers among different floral resources according to their quality. Because larger groups can potentially collect more information than smaller groups, they might benefit more from communication because it allows them to integrate and use that information to coordinate forager activity. Larger groups might also benefit more from communication because it allows them to dominate high-value resources by recruiting large numbers of foragers. By manipulating both colony size and the ability to communicate location information in the dance, we show that larger colonies of honeybees benefit more from communication than do smaller colonies. In fact, colony size and dance communication worked together to improve foraging performance; the estimated net gain per foraging trip was highest in larger colonies with unimpaired communication. These colonies also had the earliest peaks in foraging activity, but not the highest ones. This suggests they may find and recruit to resources more quickly, but not more heavily. The benefits of communication we observed in larger colonies are thus likely a result of more effective informationgathering due to massive parallel search rather than increased competitive ability due to heavy recruitment.

A selective sweep in a Varroa destructor resistant honeybee (Apis mellifera) population.

PubMed

Lattorff, H Michael G; Buchholz, Josephine; Fries, Ingemar; Moritz, Robin F A

2015-04-01

The mite Varroa destructor is one of the most dangerous parasites of the Western honeybee (Apis mellifera) causing enormous colony losses worldwide. Various chemical treatments for the control of the Varroa mite are currently in use, which, however, lead to residues in bee products and often to resistance in mites. This facilitated the exploration of alternative treatment methods and breeding for mite resistant honeybees has been in focus for breeders in many parts of the world with variable results. Another approach has been applied to a honeybee population on Gotland (Sweden) that was exposed to natural selection and survived Varroa-infestation for more than 10years without treatment. Eventually this population became resistant to the parasite by suppressing the reproduction of the mite. A previous QTL mapping study had identified a region on chromosome 7 with major loci contributing to the mite resistance. Here, a microsatellite scan of the significant candidate QTL regions was used to investigate potential footprints of selection in the original population by comparing the study population on Gotland before (2000) and after selection (2007). Genetic drift had caused an extreme loss of genetic diversity in the 2007 population for all genetic markers tested. In addition to this overall reduction of heterozygosity, two loci on chromosome 7 showed an even stronger and significant reduction in diversity than expected from genetic drift alone. Within the selective sweep eleven genes are annotated, one of them being a putative candidate to interfere with reduced mite reproduction. A glucose-methanol-choline oxidoreductase (GMCOX18) might be involved in changing volatiles emitted by bee larvae that might be essential to trigger oogenesis in Varroa. Copyright © 2015 Elsevier B.V. All rights reserved.

A Beneficial Role for Immunoglobulin E in Host Defense against Honeybee Venom Authors

PubMed Central

Marichal, Thomas; Starkl, Philipp; Reber, Laurent L.; Kalesnikoff, Janet; Oettgen, Hans C.; Tsai, Mindy; Metz, Martin; Galli, Stephen J.

2014-01-01

Summary Allergies are widely considered to be misdirected type 2 immune responses, in which IgE antibodies are produced against any of a broad range of seemingly harmless antigens. However, components of insect venoms also can sensitize individuals to develop severe IgE-associated allergic reactions, including fatal anaphylaxis, upon subsequent venom exposure. We found that mice injected with amounts of honeybee venom similar to that which could be delivered in one or two stings developed a specific type 2 immune response which increased their resistance to subsequent challenge with potentially lethal amounts of the venom. Our data indicate that IgE antibodies and the high affinity IgE receptor, FcεRI, were essential for such acquired resistance to honeybee venom. The evidence that IgE-dependent immune responses against venom can enhance survival in mice supports the hypothesis that IgE, which also contributes to allergic disorders, has an important function in protection of the host against noxious substances. PMID:24210352

Genetic structure of drone congregation areas of Africanized honeybees in southern Brazil

PubMed Central

2009-01-01

As yet, certain aspects of the Africanization process are not well understood, for example, the reproductive behavior of African and European honeybees and how the first Africanized swarms were formed and spread. Drone congregation areas (DCAs) are the ideal place to study honeybee reproduction under natural conditions since hundreds of drones from various colonies gather together in the same geographical area for mating. In the present study, we assessed the genetic structure of seven drone congregations and four commercial European-derived and Africanized apiaries in southern Brazil, employing seven microsatellite loci for this purpose. We also estimated the number of mother-colonies that drones of a specific DCA originated from. Pairwise comparison failed to reveal any population sub-structuring among the DCAs, thus indicating low mutual genetic differentiation. We also observed high genetic similarity between colonies of commercial apiaries and DCAs, besides a slight contribution from a European-derived apiary to a DCA formed nearby. Africanized DCAs seem to have a somewhat different genetic structure when compared to the European. PMID:21637465

Genetic structure of drone congregation areas of Africanized honeybees in southern Brazil.

PubMed

Collet, Thais; Cristino, Alexandre Santos; Quiroga, Carlos Fernando Prada; Soares, Ademilson Espencer Egea; Del Lama, Marco Antônio

2009-10-01

As yet, certain aspects of the Africanization process are not well understood, for example, the reproductive behavior of African and European honeybees and how the first Africanized swarms were formed and spread. Drone congregation areas (DCAs) are the ideal place to study honeybee reproduction under natural conditions since hundreds of drones from various colonies gather together in the same geographical area for mating. In the present study, we assessed the genetic structure of seven drone congregations and four commercial European-derived and Africanized apiaries in southern Brazil, employing seven microsatellite loci for this purpose. We also estimated the number of mother-colonies that drones of a specific DCA originated from. Pairwise comparison failed to reveal any population sub-structuring among the DCAs, thus indicating low mutual genetic differentiation. We also observed high genetic similarity between colonies of commercial apiaries and DCAs, besides a slight contribution from a European-derived apiary to a DCA formed nearby. Africanized DCAs seem to have a somewhat different genetic structure when compared to the European.

Evaluation of Apis mellifera syriaca Levant Region honeybee conservation using Comparative Genome Hybridization

USDA-ARS?s Scientific Manuscript database

Apis mellifera syriaca is the native honeybee subspecies of Jordan and much of the Levant Region. It expresses behavioral adaptations to a regional climate with very high temperatures, nectar dearth in summer, attacks of the Oriental wasp and is resistant to Varroa mites. The A. m. syriaca control r...

Persistence of subclinical deformed wing virus infections in honeybees following Varroa mite removal and a bee population turnover

PubMed Central

Semberg, Emilia; Forsgren, Eva; de Miranda, Joachim R.

2017-01-01

Deformed wing virus (DWV) is a lethal virus of honeybees (Apis mellifera) implicated in elevated colony mortality rates worldwide and facilitated through vector transmission by the ectoparasitic mite Varroa destructor. Clinical, symptomatic DWV infections are almost exclusively associated with high virus titres during pupal development, usually acquired through feeding by Varroa mites when reproducing on bee pupae. Control of the mite population, generally through acaricide treatment, is essential for breaking the DWV epidemic and minimizing colony losses. In this study, we evaluated the effectiveness of remedial mite control on clearing DWV from a colony. DWV titres in adult bees and pupae were monitored at 2 week intervals through summer and autumn in acaricide-treated and untreated colonies. The DWV titres in Apistan treated colonies was reduced 1000-fold relative to untreated colonies, which coincided with both the removal of mites and also a turnover of the bee population in the colony. This adult bee population turnover is probably more critical than previously realized for effective clearing of DWV infections. After this initial reduction, subclinical DWV titres persisted and even increased again gradually during autumn, demonstrating that alternative non-Varroa transmission routes can maintain the DWV titres at significant subclinical levels even after mite removal. The implications of these results for practical recommendations to mitigate deleterious subclinical DWV infections and improving honeybee health management are discussed. PMID:28686725

Honeybee associative learning performance and metabolic stress resilience are positively associated.

PubMed

Amdam, Gro V; Fennern, Erin; Baker, Nicholas; Rascón, Brenda

2010-03-17

Social-environmental influences can affect animal cognition and health. Also, human socio-economic status is a covariate factor connecting psychometric test-performance (a measure of cognitive ability), educational achievement, lifetime health, and survival. The complimentary hypothesis, that mechanisms in physiology can explain some covariance between the same traits, is disputed. Possible mechanisms involve metabolic biology affecting integrity and stability of physiological systems during development and ageing. Knowledge of these relationships is incomplete, and underlying processes are challenging to reveal in people. Model animals, however, can provide insights into connections between metabolic biology and physiological stability that may aid efforts to reduce human health and longevity disparities. We document a positive correlation between a measure of associative learning performance and the metabolic stress resilience of honeybees. This relationship is independent of social factors, and may provide basic insights into how central nervous system (CNS) function and metabolic biology can be associated. Controlling for social environment, age, and learning motivation in each bee, we establish that learning in Pavlovian conditioning to an odour is positively correlated with individual survival time in hyperoxia. Hyperoxia induces oxidative metabolic damage, and provides a measure of metabolic stress resistance that is often related to overall lifespan in laboratory animals. The positive relationship between Pavlovian learning ability and stress resilience in the bee is not equally established in other model organisms so far, and contrasts with a genetic cost of improved associative learning found in Drosophila melanogaster. Similarities in the performances of different animals need not reflect common functional principles. A correlation of honeybee Pavlovian learning and metabolic stress resilience, thereby, is not evidence of a shared biology that will give

New approach for determination of an optimum honeybee colony's carrying capacity based on productivity and nectar secretion potential of bee forage species.

PubMed

Al-Ghamdi, Ahmed; Adgaba, Nuru; Getachew, Awraris; Tadesse, Yilma

2016-01-01

The present study was carried out to determine an optimum honeybee colony's carrying capacity of selected valleys dominated by Ziziphus spina-christi and Acacia tortilis in the Al-Baha region, Kingdom of Saudi Arabia. The study was conducted based on the assessment of the number of colonies kept, their productivities and the existing productive bee forage resources in the target valleys with its economic implication. In the existing beekeeping practice, the average number of managed honeybee colonies introduced per square kilometer was 530 and 317 during the flowering period of Z. spina-christi and A. tortilis, respectively. Furthermore, the overall ratios of productive bee forage plants to the number of honeybee colonies introduced were 0.55 and 11.12 to Ziziphus trees and A. tortilis shrubs respectively. In the existing situation the average honey production potential of 5.21 and 0.34 kg was recorded per Ziziphus and A. tortilis plants per flowering season, respectively. The present study, revealed that the number of honeybee colonies introduced in relation to the existing bee forage potential was extremely overcrowding which is beyond the carrying capacity of bee forage resources in selected valleys and it has been observed to affect the productivities and subsequent profitability of beekeeping. The study infers that, by keeping the optimum honeybee colony's carrying capacity of valleys (88 traditional hives/km(2) or 54 Langstroth hives/km(2) in Ziziphus field and 72 traditional hives/km(2) or 44 Langstroth hives/km(2) in A. tortilis field), profitability of beekeeping can be boosted up to 130.39% and 207.98% during Z. spina-christi and A. tortilis, flowering seasons, respectively.

Sensory coding of nest-site value in honeybee swarms.

PubMed

Seeley, Thomas D; Visscher, P Kirk

2008-12-01

This study investigates the first stage of the decision-making process of a honeybee swarm as it chooses a nest site: how a scout bee codes the value of a potential nest site in the waggle dances she produces to represent this site. We presented honeybee swarms with a two-alternative choice between a high-value site and a medium-value site and recorded the behavior of individually identifiable scout bees as they reported on these two alternatives. We found that bees performed equally lengthy inspections at the two sites, but that, on the swarm cluster, they performed more dance circuits per bee for the high-value site. We also found that there was much individual-level noise in the coding of site value, but that there were clear population-level differences in total dance circuits produced for the two sites. The first bee to find a site had a high probability of reporting the site with a waggle dance, regardless of its value. This discoverer-should-dance phenomenon may help ensure that a swarm gives attention to all discovered sites. There was rapid decay in the dance response; the number of dance circuits produced by a bee after visiting a site decreased linearly over sequential visits, and eventually each bee ceased visiting her site. This decay, or ;leakage', in the accumulation of bees at a site improves a swarm's decision-making ability by helping a swarm avoid making fast-decision errors.

Does Fine Color Discrimination Learning in Free-Flying Honeybees Change Mushroom-Body Calyx Neuroarchitecture?

PubMed Central

Sommerlandt, Frank M. J.; Spaethe, Johannes; Rössler, Wolfgang; Dyer, Adrian G.

2016-01-01

Honeybees learn color information of rewarding flowers and recall these memories in future decisions. For fine color discrimination, bees require differential conditioning with a concurrent presentation of target and distractor stimuli to form a long-term memory. Here we investigated whether the long-term storage of color information shapes the neural network of microglomeruli in the mushroom body calyces and if this depends on the type of conditioning. Free-flying honeybees were individually trained to a pair of perceptually similar colors in either absolute conditioning towards one of the colors or in differential conditioning with both colors. Subsequently, bees of either conditioning groups were tested in non-rewarded discrimination tests with the two colors. Only bees trained with differential conditioning preferred the previously learned color, whereas bees of the absolute conditioning group, and a stimuli-naïve group, chose randomly among color stimuli. All bees were then kept individually for three days in the dark to allow for complete long-term memory formation. Whole-mount immunostaining was subsequently used to quantify variation of microglomeruli number and density in the mushroom-body lip and collar. We found no significant differences among groups in neuropil volumes and total microglomeruli numbers, but learning performance was negatively correlated with microglomeruli density in the absolute conditioning group. Based on these findings we aim to promote future research approaches combining behaviorally relevant color learning tests in honeybees under free-flight conditions with neuroimaging analysis; we also discuss possible limitations of this approach. PMID:27783640

Autosomal and Mitochondrial Adaptation Following Admixture: A Case Study on the Honeybees of Reunion Island

PubMed Central

Wragg, David; Techer, Maéva Angélique; Canale-Tabet, Kamila; Basso, Benjamin; Bidanel, Jean-Pierre; Labarthe, Emmanuelle; Bouchez, Olivier; Le Conte, Yves; Clémencet, Johanna; Delatte, Hélène

2018-01-01

Abstract The honeybee population of the tropical Reunion Island is a genetic admixture of the Apis mellifera unicolor subspecies, originally described in Madagascar, and of European subspecies, mainly A. m. carnica and A. m. ligustica, regularly imported to the island since the late 19th century. We took advantage of this population to study genetic admixing of the tropical-adapted indigenous and temperate-adapted European genetic backgrounds. Whole genome sequencing of 30 workers and 6 males from Reunion, compared with samples from Europe, Madagascar, Mauritius, Rodrigues, and the Seychelles, revealed the Reunion honeybee population to be composed on an average of 53.2 ± 5.9% A. m. unicolor nuclear genomic background, the rest being mainly composed of A. m. carnica and to a lesser extent A. m. ligustica. In striking contrast to this, only 1 out of the 36 honeybees from Reunion had a mitochondrial genome of European origin, suggesting selection has favored the A. m. unicolor mitotype, which is possibly better adapted to the island’s bioclimate. Local ancestry was determined along the chromosomes for all Reunion samples, and a test for preferential selection for the A. m. unicolor or European background revealed 15 regions significantly associated with the A. m. unicolor lineage and 9 regions with the European lineage. Our results provide insights into the long-term consequences of introducing exotic specimen on the nuclear and mitochondrial genomes of locally adapted populations. PMID:29202174

Diversity of honey stores and their impact on pathogenic bacteria of the honeybee, Apis mellifera

PubMed Central

Erler, Silvio; Denner, Andreas; Bobiş, Otilia; Forsgren, Eva; Moritz, Robin F A

2014-01-01

Honeybee colonies offer an excellent environment for microbial pathogen development. The highest virulent, colony killing, bacterial agents are Paenibacillus larvae causing American foulbrood (AFB), and European foulbrood (EFB) associated bacteria. Besides the innate immune defense, honeybees evolved behavioral defenses to combat infections. Foraging of antimicrobial plant compounds plays a key role for this “social immunity” behavior. Secondary plant metabolites in floral nectar are known for their antimicrobial effects. Yet, these compounds are highly plant specific, and the effects on bee health will depend on the floral origin of the honey produced. As worker bees not only feed themselves, but also the larvae and other colony members, honey is a prime candidate acting as self-medication agent in honeybee colonies to prevent or decrease infections. Here, we test eight AFB and EFB bacterial strains and the growth inhibitory activity of three honey types. Using a high-throughput cell growth assay, we show that all honeys have high growth inhibitory activity and the two monofloral honeys appeared to be strain specific. The specificity of the monofloral honeys and the strong antimicrobial potential of the polyfloral honey suggest that the diversity of honeys in the honey stores of a colony may be highly adaptive for its “social immunity” against the highly diverse suite of pathogens encountered in nature. This ecological diversity may therefore operate similar to the well-known effects of host genetic variance in the arms race between host and parasite. PMID:25505523

Two Waves of Transcription Are Required for Long-Term Memory in the Honeybee

ERIC Educational Resources Information Center

Lefer, Damien; Perisse, Emmanuel; Hourcade, Benoit; Sandoz, JeanChristophe; Devaud, Jean-Marc

2013-01-01

Storage of information into long-term memory (LTM) usually requires at least two waves of transcription in many species. However, there is no clear evidence of this phenomenon in insects, which are influential models for memory studies. We measured retention in honeybees after injecting a transcription inhibitor at different times before and after…

Expression of recombinant AccMRJP1 protein from royal jelly of Chinese honeybee in Pichia pastoris and its proliferation activity in an insect cell line

USDA-ARS?s Scientific Manuscript database

Main royal jelly protein 1 (MRJP1) is the most abundant member of the main royal jelly protein (MRJP) family among honeybees. Mature MRJP1 cDNA of the Chinese honeybee (Apis cerana cerana MRJP1, or AccMRJP1) was expressed in Pichia pastoris. SDS-PAGE showed that recombinant AccMRJP1 was identical in...

Bigger is better: honeybee colonies as distributed information-gathering systems

PubMed Central

Donaldson-Matasci, Matina C.; DeGrandi-Hoffman, Gloria; Dornhaus, Anna

2015-01-01

In collectively foraging groups, communication about food resources can play an important role in the organization of the group’s activity. For example, the honeybee dance communication system allows colonies to selectively allocate foragers among different floral resources according to their quality. Because larger groups can potentially collect more information than smaller groups, they might benefit more from communication because it allows them to integrate and use that information to coordinate forager activity. Larger groups might also benefit more from communication because it allows them to dominate high-value resources by recruiting large numbers of foragers. By manipulating both colony size and the ability to communicate location information in the dance, we show that larger colonies of honeybees benefit more from communication than do smaller colonies. In fact, colony size and dance communication worked together to improve foraging performance; the estimated net gain per foraging trip was highest in larger colonies with unimpaired communication. These colonies also had the earliest peaks in foraging activity, but not the highest ones. This suggests they may find and recruit to resources more quickly, but not more heavily. The benefits of communication we observed in larger colonies are thus likely a result of more effective informationgathering due to massive parallel search rather than increased competitive ability due to heavy recruitment. PMID:26213412

Reproductive interference between honeybee species in artificial sympatry.

PubMed

Remnant, Emily J; Koetz, Anna; Tan, Ken; Hinson, Eloise; Beekman, Madeleine; Oldroyd, Benjamin P

2014-03-01

Reproductive isolation between closely related species is often incomplete. The Western honeybee, Apis mellifera, and the Eastern hive bee, Apis cerana, have been allopatric for millions of years, but are nonetheless similar in morphology and behaviour. During the last century, the two species were brought into contact anthropogenically, providing potential opportunities for interspecific matings. Hybrids between A. mellifera and A. cerana are inviable, so natural interspecific matings are of concern because they may reduce the viability of A. cerana and A. mellifera populations - two of the world's most important pollinators. We examined the mating behaviour of A. mellifera and A. cerana queens and drones from Caoba Basin, China and Cairns, Australia. Drone mating flight times overlap in both areas. Analysis of the spermathecal contents of queens with species-specific genetic markers indicated that in Caoba Basin, 14% of A. mellifera queens mated with at least one A. cerana male, but we detected no A. cerana queens that had mated with A. mellifera males. Similarly, in Cairns, no A. cerana queens carried A. mellifera sperm, but one-third of A. mellifera queens had mated with at least one A. cerana male. No hybrid embryos were detected in eggs laid by interspecifically mated A. mellifera queens in either location. However, A. mellifera queens artificially inseminated with A. cerana sperm produced inviable hybrid eggs or unfertilized drones. This suggests that reproductive interference will impact the viability of honeybee populations wherever A. cerana and A. mellifera are in contact. © 2014 John Wiley & Sons Ltd.

Origin and function of the major royal jelly proteins of the honeybee (Apis mellifera) as members of the yellow gene family.

PubMed

Buttstedt, Anja; Moritz, Robin F A; Erler, Silvio

2014-05-01

In the honeybee, Apis mellifera, the queen larvae are fed with a diet exclusively composed of royal jelly (RJ), a secretion of the hypopharyngeal gland of young worker bees that nurse the brood. Up to 15% of RJ is composed of proteins, the nine most abundant of which have been termed major royal jelly proteins (MRJPs). Although it is widely accepted that RJ somehow determines the fate of a female larva and in spite of considerable research efforts, there are surprisingly few studies that address the biochemical characterisation and functions of these MRJPs. Here we review the research on MRJPs not only in honeybees but in hymenopteran insects in general and provide metadata analyses on genome organisation of mrjp genes, corroborating previous reports that MRJPs have important functions for insect development and not just a nutritional value for developing honeybee larvae. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

Interaction between Varroa destructor and imidacloprid reduces flight capacity of honeybees.

PubMed

Blanken, Lisa J; van Langevelde, Frank; van Dooremalen, Coby

2015-12-07

Current high losses of honeybees seriously threaten crop pollination. Whereas parasite exposure is acknowledged as an important cause of these losses, the role of insecticides is controversial. Parasites and neonicotinoid insecticides reduce homing success of foragers (e.g. by reduced orientation), but it is unknown whether they negatively affect flight capacity. We investigated how exposing colonies to the parasitic mite Varroa destructor and the neonicotinoid insecticide imidacloprid affect flight capacity of foragers. Flight distance, time and speed of foragers were measured in flight mills to assess the relative and interactive effects of high V. destructor load and a field-realistic, chronic sub-lethal dose of imidacloprid. Foragers from colonies exposed to high levels of V. destructor flew shorter distances, with a larger effect when also exposed to imidacloprid. Bee body mass partly explained our results as bees were heavier when exposed to these stressors, possibly due to an earlier onset of foraging. Our findings contribute to understanding of interacting stressors that can explain colony losses. Reduced flight capacity decreases the food-collecting ability of honeybees and may hamper the use of precocious foraging as a coping mechanism during colony (nutritional) stress. Ineffective coping mechanisms may lead to destructive cascading effects and subsequent colony collapse. © 2015 The Author(s).

Interaction between Varroa destructor and imidacloprid reduces flight capacity of honeybees

PubMed Central

Blanken, Lisa J.; van Dooremalen, Coby

2015-01-01

Current high losses of honeybees seriously threaten crop pollination. Whereas parasite exposure is acknowledged as an important cause of these losses, the role of insecticides is controversial. Parasites and neonicotinoid insecticides reduce homing success of foragers (e.g. by reduced orientation), but it is unknown whether they negatively affect flight capacity. We investigated how exposing colonies to the parasitic mite Varroa destructor and the neonicotinoid insecticide imidacloprid affect flight capacity of foragers. Flight distance, time and speed of foragers were measured in flight mills to assess the relative and interactive effects of high V. destructor load and a field-realistic, chronic sub-lethal dose of imidacloprid. Foragers from colonies exposed to high levels of V. destructor flew shorter distances, with a larger effect when also exposed to imidacloprid. Bee body mass partly explained our results as bees were heavier when exposed to these stressors, possibly due to an earlier onset of foraging. Our findings contribute to understanding of interacting stressors that can explain colony losses. Reduced flight capacity decreases the food-collecting ability of honeybees and may hamper the use of precocious foraging as a coping mechanism during colony (nutritional) stress. Ineffective coping mechanisms may lead to destructive cascading effects and subsequent colony collapse. PMID:26631559

Using whole genome sequencing to study American foulbrood epidemiology in honeybees

PubMed Central

Ågren, Joakim; Schäfer, Marc Oliver

2017-01-01

American foulbrood (AFB), caused by Paenibacillus larvae, is a devastating disease in honeybees. In most countries, the disease is controlled through compulsory burning of symptomatic colonies causing major economic losses in apiculture. The pathogen is endemic to honeybees world-wide and is readily transmitted via the movement of hive equipment or bees. Molecular epidemiology of AFB currently largely relies on placing isolates in one of four ERIC-genotypes. However, a more powerful alternative is multi-locus sequence typing (MLST) using whole-genome sequencing (WGS), which allows for high-resolution studies of disease outbreaks. To evaluate WGS as a tool for AFB-epidemiology, we applied core genome MLST (cgMLST) on isolates from a recent outbreak of AFB in Sweden. The high resolution of the cgMLST allowed different bacterial clones involved in the disease outbreak to be identified and to trace the source of infection. The source was found to be a beekeeper who had sold bees to two other beekeepers, proving the epidemiological link between them. No such conclusion could have been made using conventional MLST or ERIC-typing. This is the first time that WGS has been used to study the epidemiology of AFB. The results show that the technique is very powerful for high-resolution tracing of AFB-outbreaks. PMID:29140998

Antennal tactile learning in the honeybee: effect of nicotinic antagonists on memory dynamics.

PubMed

Dacher, M; Lagarrigue, A; Gauthier, M

2005-01-01

Restrained worker honeybees (Apis mellifera L.) are able to learn to associate antennal-scanning of a metal plate with a sucrose reinforcement delivered to the mouthparts. Learning occurs reliably in a single association of the two sensory stimuli. The involvement of nicotinic pathways in memory formation and retrieval processes was tested by injecting, into the whole brain through the median ocellus, either mecamylamine (0.6 microg per bee) or alpha-bungarotoxin (2.4 ng per bee). Saline served as a control. Mecamylamine injected 10 min before the retrieval test impairs the retention level tested 3 h and 24 h after single- or multi-trial learning. Retrieval tests performed at various times after the injection show that the blocking effect of mecamylamine lasts about 1 h. The drug has no effect on the reconsolidation or extinction processes. Mecamylamine injected 10 min before conditioning impairs single-trial learning but has no effect on five-trial learning and on the consolidation process. By contrast, alpha-bungarotoxin only impairs the formation of long-term memory (24 h) induced by the five-trial learning and has no effect on medium-term memory (3 h), on single-trial learning or on the retrieval process. Hence, owing to previous data, at least two kinds of nicotinic receptors seem to be involved in honeybee memory, an alpha-bungarotoxin-sensitive and an alpha-bungarotoxin-insensitive receptor. Our results extend to antennal mechanosensory conditioning the role of the cholinergic system that we had previously described for olfactory conditioning in the honeybee. Moreover, we describe here in this insect a pharmacological dissociation between alpha-bungarotoxin sensitive long-term memory and alpha-bungarotoxin insensitive medium-term memory, the last one being affected by mecamylamine.

Spontaneous Recovery after Extinction of the Conditioned Proboscis Extension Response in the Honeybee

ERIC Educational Resources Information Center

Sandoz, Jean-Christophe; Pham-Delegue, Minh-Ha

2004-01-01

In honeybees, the proboscis extension response (PER) can be conditioned by associating an odor stimulus (CS) to a sucrose reward (US). Conditioned responses to the CS, which are acquired by most bees after a single CS-US pairing, disappear after repeated unrewarded presentations of the CS, a process called extinction. Extinction is usually thought…

Optimization of power utilization in multimobile robot foraging behavior inspired by honeybees system.

PubMed

Ahmad, Faisul Arif; Ramli, Abd Rahman; Samsudin, Khairulmizam; Hashim, Shaiful Jahari

2014-01-01

Deploying large numbers of mobile robots which can interact with each other produces swarm intelligent behavior. However, mobile robots are normally running with finite energy resource, supplied from finite battery. The limitation of energy resource required human intervention for recharging the batteries. The sharing information among the mobile robots would be one of the potentials to overcome the limitation on previously recharging system. A new approach is proposed based on integrated intelligent system inspired by foraging of honeybees applied to multimobile robot scenario. This integrated approach caters for both working and foraging stages for known/unknown power station locations. Swarm mobile robot inspired by honeybee is simulated to explore and identify the power station for battery recharging. The mobile robots will share the location information of the power station with each other. The result showed that mobile robots consume less energy and less time when they are cooperating with each other for foraging process. The optimizing of foraging behavior would result in the mobile robots spending more time to do real work.

Optimization of Power Utilization in Multimobile Robot Foraging Behavior Inspired by Honeybees System

PubMed Central

Ahmad, Faisul Arif; Ramli, Abd Rahman; Samsudin, Khairulmizam; Hashim, Shaiful Jahari

2014-01-01

Deploying large numbers of mobile robots which can interact with each other produces swarm intelligent behavior. However, mobile robots are normally running with finite energy resource, supplied from finite battery. The limitation of energy resource required human intervention for recharging the batteries. The sharing information among the mobile robots would be one of the potentials to overcome the limitation on previously recharging system. A new approach is proposed based on integrated intelligent system inspired by foraging of honeybees applied to multimobile robot scenario. This integrated approach caters for both working and foraging stages for known/unknown power station locations. Swarm mobile robot inspired by honeybee is simulated to explore and identify the power station for battery recharging. The mobile robots will share the location information of the power station with each other. The result showed that mobile robots consume less energy and less time when they are cooperating with each other for foraging process. The optimizing of foraging behavior would result in the mobile robots spending more time to do real work. PMID:24949491

Changes in cellular degradation activity in young and old worker honeybees (Apis mellifera).

PubMed

Hsu, Chin-Yuan; Chuang, Yu-Lung; Chan, Yu-Pei

2014-02-01

The trophocytes and fat cells of honeybees (Apis mellifera) have been used in cellular senescence studies, but the changes of cellular degradation activity with aging in workers are unknown. In this study, cellular degradation activity was evaluated in the trophocytes and fat cells of young and old workers reared in a field hive. The results showed the following: (1) 20S proteosome activity decreased with aging, whereas its expression increased with aging; (2) the expression of microtubule-associated protein 1 light chain 3-II (LC3-II) and the 70 kD heat shock cognate protein (Hsc70) decreased with aging; (3) the size and number of autophagic vacuoles decreased with aging; (4) p62/SQSTM1 and polyubiquitin aggregate expression decreased with aging; (5) lysosomal efficiency decreased with aging; and (6) molecular target of rapamycin (mTOR) expression increased with aging. These results indicate that young workers have higher levels of cellular degradation activity than old workers and that aging results in a decline in the cellular degradation activity in worker honeybees. Copyright © 2013 Elsevier Inc. All rights reserved.

Association of Amine-Receptor DNA Sequence Variants with Associative Learning in the Honeybee.

PubMed

Lagisz, Malgorzata; Mercer, Alison R; de Mouzon, Charlotte; Santos, Luana L S; Nakagawa, Shinichi

2016-03-01

Octopamine- and dopamine-based neuromodulatory systems play a critical role in learning and learning-related behaviour in insects. To further our understanding of these systems and resulting phenotypes, we quantified DNA sequence variations at six loci coding octopamine-and dopamine-receptors and their association with aversive and appetitive learning traits in a population of honeybees. We identified 79 polymorphic sequence markers (mostly SNPs and a few insertions/deletions) located within or close to six candidate genes. Intriguingly, we found that levels of sequence variation in the protein-coding regions studied were low, indicating that sequence variation in the coding regions of receptor genes critical to learning and memory is strongly selected against. Non-coding and upstream regions of the same genes, however, were less conserved and sequence variations in these regions were weakly associated with between-individual differences in learning-related traits. While these associations do not directly imply a specific molecular mechanism, they suggest that the cross-talk between dopamine and octopamine signalling pathways may influence olfactory learning and memory in the honeybee.

Conditional withholding of proboscis extension in honeybees (Apis mellifera) during discriminative punishment.

PubMed

Smith, B H; Abramson, C I; Tobin, T R

1991-12-01

Proboscis extension conditioning of honeybee workers was used to test the ability of bees to respond to appetitive and aversive stimuli while restrained in a harness that allows subjects to move their antennae and mouthparts (Kuwabara, 1957; Menzel, Erber, & Masuhr, 1974). Subjects were conditioned to discriminate between two odors, one associated with sucrose feeding and the other associated with a 10 V AC shock if they responded to the sucrose unconditioned stimulus (US) in the context of that odor. Most Ss readily learned to respond to the odor followed by sucrose feeding and not to the odor associated with sucrose stimulation plus shock. Furthermore, in the context of the odor associated with shock, significantly more subjects withheld or delayed proboscis extension on stimulation with the sucrose US than they did in the context of the odor associated with feeding. Thus, restrained honeybees can readily learn to avoid shock according to an odor context by withholding proboscis extension to a normally powerful releaser. Analysis of individual learning curves revealed that subjects differed markedly in performance on this task. Some learn the discrimination quickly, whereas others show different kinds of response patterns.

General principles in motion vision: color blindness of object motion depends on pattern velocity in honeybee and goldfish.

PubMed

Stojcev, Maja; Radtke, Nils; D'Amaro, Daniele; Dyer, Adrian G; Neumeyer, Christa

2011-07-01

Visual systems can undergo striking adaptations to specific visual environments during evolution, but they can also be very "conservative." This seems to be the case in motion vision, which is surprisingly similar in species as distant as honeybee and goldfish. In both visual systems, motion vision measured with the optomotor response is color blind and mediated by one photoreceptor type only. Here, we ask whether this is also the case if the moving stimulus is restricted to a small part of the visual field, and test what influence velocity may have on chromatic motion perception. Honeybees were trained to discriminate between clockwise- and counterclockwise-rotating sector disks. Six types of disk stimuli differing in green receptor contrast were tested using three different rotational velocities. When green receptor contrast was at a minimum, bees were able to discriminate rotation directions with all colored disks at slow velocities of 6 and 12 Hz contrast frequency but not with a relatively high velocity of 24 Hz. In the goldfish experiment, the animals were trained to detect a moving red or blue disk presented in a green surround. Discrimination ability between this stimulus and a homogenous green background was poor when the M-cone type was not or only slightly modulated considering high stimulus velocity (7 cm/s). However, discrimination was improved with slower stimulus velocities (4 and 2 cm/s). These behavioral results indicate that there is potentially an object motion system in both honeybee and goldfish, which is able to incorporate color information at relatively low velocities but is color blind with higher speed. We thus propose that both honeybees and goldfish have multiple subsystems of object motion, which include achromatic as well as chromatic processing.

Behavioral and neural plasticity caused by early social experiences: the case of the honeybee

PubMed Central

Arenas, Andrés; Ramírez, Gabriela P.; Balbuena, María Sol; Farina, Walter M.

2013-01-01

Cognitive experiences during the early stages of life play an important role in shaping future behavior. Behavioral and neural long-term changes after early sensory and associative experiences have been recently reported in the honeybee. This invertebrate is an excellent model for assessing the role of precocious experiences on later behavior due to its extraordinarily tuned division of labor based on age polyethism. These studies are mainly focused on the role and importance of experiences occurred during the first days of the adult lifespan, their impact on foraging decisions, and their contribution to coordinate food gathering. Odor-rewarded experiences during the first days of honeybee adulthood alter the responsiveness to sucrose, making young hive bees more sensitive to assess gustatory features about the nectar brought back to the hive and affecting the dynamic of the food transfers and the propagation of food-related information within the colony. Early olfactory experiences lead to stable and long-term associative memories that can be successfully recalled after many days, even at foraging ages. Also they improve memorizing of new associative learning events later in life. The establishment of early memories promotes stable reorganization of the olfactory circuits inducing structural and functional changes in the antennal lobe (AL). Early rewarded experiences have relevant consequences at the social level too, biasing dance and trophallaxis partner choice and affecting recruitment. Here, we revised recent results in bees' physiology, behavior, and sociobiology to depict how the early experiences affect their cognition abilities and neural-related circuits. PMID:23986708

Aversive Learning of Colored Lights in Walking Honeybees

PubMed Central

Kirkerud, Nicholas H.; Schlegel, Ulrike; Giovanni Galizia, C.

2017-01-01

The honeybee has been established as an important model organism in studies on visual learning. So far the emphasis has been on appetitive conditioning, simulating floral discrimination, and homing behavior, where bees perform exceptionally well in visual discrimination tasks. However, bees in the wild also face dangers, and recent findings suggest that what is learned about visual percepts is highly context dependent. A stimulus that follows an unpleasant period, is associated with the feeling of relief- or safety in humans and animals, thus acquiring a positive meaning. Whether this is also the case in honeybees is still an open question. Here, we conditioned bees aversively in a walking arena where each half was illuminated by light of a specific wavelength and intensity, one of which was combined with electric shocks. In this paradigm, the bees' preferences to the different lights were modified through nine conditioning trials, forming robust escape, and avoidance behaviors. Strikingly, we found that while 465 nm (human blue) and 590 nm (human yellow) lights both could acquire negative valences (inducing avoidance response), 525 nm (human green) light could not. This indicates that green light holds an innate meaning of safety which is difficult to overrule even through intensive aversive conditioning. The bees had slight initial preferences to green over the blue and the yellow lights, which could be compensated by adjusting light intensity. However, this initial bias played a minor role while the chromatic properties were the most salient characteristics of the light stimuli during aversive conditioning. Moreover, bees could learn the light signaling safety, revealing the existence of a relief component in aversive operant conditioning, similar to what has been observed in other animals. PMID:28588460

New approach for determination of an optimum honeybee colony’s carrying capacity based on productivity and nectar secretion potential of bee forage species

PubMed Central

Al-Ghamdi, Ahmed; Adgaba, Nuru; Getachew, Awraris; Tadesse, Yilma

2014-01-01

The present study was carried out to determine an optimum honeybee colony’s carrying capacity of selected valleys dominated by Ziziphus spina-christi and Acacia tortilis in the Al-Baha region, Kingdom of Saudi Arabia. The study was conducted based on the assessment of the number of colonies kept, their productivities and the existing productive bee forage resources in the target valleys with its economic implication. In the existing beekeeping practice, the average number of managed honeybee colonies introduced per square kilometer was 530 and 317 during the flowering period of Z. spina-christi and A. tortilis, respectively. Furthermore, the overall ratios of productive bee forage plants to the number of honeybee colonies introduced were 0.55 and 11.12 to Ziziphus trees and A. tortilis shrubs respectively. In the existing situation the average honey production potential of 5.21 and 0.34 kg was recorded per Ziziphus and A. tortilis plants per flowering season, respectively. The present study, revealed that the number of honeybee colonies introduced in relation to the existing bee forage potential was extremely overcrowding which is beyond the carrying capacity of bee forage resources in selected valleys and it has been observed to affect the productivities and subsequent profitability of beekeeping. The study infers that, by keeping the optimum honeybee colony’s carrying capacity of valleys (88 traditional hives/km2 or 54 Langstroth hives/km2 in Ziziphus field and 72 traditional hives/km2 or 44 Langstroth hives/km2 in A. tortilis field), profitability of beekeeping can be boosted up to 130.39% and 207.98% during Z. spina-christi and A. tortilis, flowering seasons, respectively. PMID:26858544

Developmental regulation of ecdysone receptor (EcR) and EcR-controlled gene expression during pharate-adult development of honeybees (Apis mellifera)

PubMed Central

Mello, Tathyana R. P.; Aleixo, Aline C.; Pinheiro, Daniel G.; Nunes, Francis M. F.; Bitondi, Márcia M. G.; Hartfelder, Klaus; Barchuk, Angel R.; Simões, Zilá L. P.

2014-01-01

Major developmental transitions in multicellular organisms are driven by steroid hormones. In insects, these, together with juvenile hormone (JH), control development, metamorphosis, reproduction and aging, and are also suggested to play an important role in caste differentiation of social insects. Here, we aimed to determine how EcR transcription and ecdysteroid titers are related during honeybee postembryonic development and what may actually be the role of EcR in caste development of this social insect. In addition, we expected that knocking-down EcR gene expression would give us information on the participation of the respective protein in regulating downstream targets of EcR. We found that in Apis mellifera females, EcR-A is the predominantly expressed variant in postembryonic development, while EcR-B transcript levels are higher in embryos, indicating an early developmental switch in EcR function. During larval and pupal stages, EcR-B expression levels are very low, while EcR-A transcripts are more variable and abundant in workers compared to queens. Strikingly, these transcript levels are opposite to the ecdysteroid titer profile. 20-hydroxyecdysone (20E) application experiments revealed that low 20E levels induce EcR expression during development, whereas high ecdysteroid titers seem to be repressive. By means of RNAi-mediated knockdown (KD) of both EcR transcript variants we detected the differential expression of 234 poly-A+ transcripts encoding genes such as CYPs, MRJPs and certain hormone response genes (Kr-h1 and ftz-f1). EcR-KD also promoted the differential expression of 70 miRNAs, including highly conserved ones (e.g., miR-133 and miR-375), as well honeybee-specific ones (e.g., miR-3745 and miR-3761). Our results put in evidence a broad spectrum of EcR-controlled gene expression during postembryonic development of honeybees, revealing new facets of EcR biology in this social insect. PMID:25566327

The organization of honeybee ocelli: Regional specializations and rhabdom arrangements.

PubMed

Ribi, Willi; Warrant, Eric; Zeil, Jochen

2011-11-01

We have re-investigated the organization of ocelli in honeybee workers and drones. Ocellar lenses are divided into a dorsal and a ventral part by a cusp-shaped indentation. The retina is also divided, with a ventral retina looking skywards and a dorsal retina looking at the horizon. The focal plane of lenses lies behind the retina in lateral ocelli, but within the dorsal retina in the median ocellus of both workers and drones. Ventral retinula cells are ca. 25μm long with dense screening pigments. Dorsal retinula cells are ca. 60μm long with sparse pigmentation mainly restricted to their proximal parts. Pairs of retinula cells form flat, non-twisting rhabdom sheets with elongated, straight, rectangular cross-sections, on average 8.7μm long and 1μm wide. Honeybee ocellar rhabdoms have shorter and straighter cross-sections than those recently described in the night-active bee Megalopta genalis. Across the retina, rhabdoms form a fan-shaped pattern of orientations. In each ocellus, ventral and dorsal retinula cell axons project into two separate neuropils, converging on few large neurons in the dorsal, and on many small neurons in the ventral neuropil. The divided nature of the ocelli, together with the particular construction and arrangement of rhabdoms, suggest that ocelli are not only involved in attitude control, but might also provide skylight polarization compass information. Copyright © 2011 Elsevier Ltd. All rights reserved.

A DNA Barcoding Approach to Characterize Pollen Collected by Honeybees

PubMed Central

Bruni, Ilaria; Scaccabarozzi, Daniela; Sandionigi, Anna; Barbuto, Michela; Casiraghi, Maurizio; Labra, Massimo

2014-01-01

In the present study, we investigated DNA barcoding effectiveness to characterize honeybee pollen pellets, a food supplement largely used for human nutrition due to its therapeutic properties. We collected pollen pellets using modified beehives placed in three zones within an alpine protected area (Grigna Settentrionale Regional Park, Italy). A DNA barcoding reference database, including rbcL and trnH-psbA sequences from 693 plant species (104 sequenced in this study) was assembled. The database was used to identify pollen collected from the hives. Fifty-two plant species were identified at the molecular level. Results suggested rbcL alone could not distinguish among congeneric plants; however, psbA-trnH identified most of the pollen samples at the species level. Substantial variability in pollen composition was observed between the highest elevation locality (Alpe Moconodeno), characterized by arid grasslands and a rocky substrate, and the other two sites (Cornisella and Ortanella) at lower altitudes. Pollen from Ortanella and Cornisella showed the presence of typical deciduous forest species; however in samples collected at Ortanella, pollen of the invasive Lonicera japonica, and the ornamental Pelargonium x hortorum were observed. Our results indicated pollen composition was largely influenced by floristic local biodiversity, plant phenology, and the presence of alien flowering species. Therefore, pollen molecular characterization based on DNA barcoding might serve useful to beekeepers in obtaining honeybee products with specific nutritional or therapeutic characteristics desired by food market demands. PMID:25296114

Honeybee navigation: following routes using polarized-light cues

PubMed Central

Kraft, P.; Evangelista, C.; Dacke, M.; Labhart, T.; Srinivasan, M. V.

2011-01-01

While it is generally accepted that honeybees (Apis mellifera) are capable of using the pattern of polarized light in the sky to navigate to a food source, there is little or no direct behavioural evidence that they actually do so. We have examined whether bees can be trained to find their way through a maze composed of four interconnected tunnels, by using directional information provided by polarized light illumination from the ceilings of the tunnels. The results show that bees can learn this task, thus demonstrating directly, and for the first time, that bees are indeed capable of using the polarized-light information in the sky as a compass to steer their way to a food source. PMID:21282174

Effect of temperature on the biotic potential of honeybee microsporidia.

PubMed

Martín-Hernández, Raquel; Meana, Aránzazu; García-Palencia, Pilar; Marín, Pilar; Botías, Cristina; Garrido-Bailón, Encarna; Barrios, Laura; Higes, Mariano

2009-04-01

The biological cycle of Nosema spp. in honeybees depends on temperature. When expressed as total spore counts per day after infection, the biotic potentials of Nosema apis and N. ceranae at 33 degrees C were similar, but a higher proportion of immature stages of N. ceranae than of N. apis were seen. At 25 and 37 degrees C, the biotic potential of N. ceranae was higher than that of N. apis. The better adaptation of N. ceranae to complete its endogenous cycle at different temperatures clearly supports the observation of the different epidemiological patterns.

The proboscis extension reflex to evaluate learning and memory in honeybees ( Apis mellifera): some caveats

NASA Astrophysics Data System (ADS)

Frost, Elisabeth H.; Shutler, Dave; Hillier, Neil Kirk

2012-09-01

The proboscis extension reflex (PER) is widely used in a classical conditioning (Pavlovian) context to evaluate learning and memory of a variety of insect species. The literature is particularly prodigious for honeybees ( Apis mellifera) with more than a thousand publications. Imagination appears to be the only limit to the types of challenges to which researchers subject honeybees, including all the sensory modalities and a broad diversity of environmental treatments. Accordingly, some remarkable insights have been achieved using PER. However, there are several challenges to evaluating the PER literature that warrant a careful and thorough review. We assess here variation in methods that makes interpretation of studies, even those researching the same question, tenuous. We suggest that the numerous variables that might influence experimental outcomes from PER be thoroughly detailed by researchers. Moreover, the influence of individual variables on results needs to carefully evaluated, as well as among two or more variables. Our intent is to encourage investigation of the influence of numerous variables on PER results.

Oxidative stress and anti-oxidant enzyme activities in the trophocytes and fat cells of queen honeybees (Apis mellifera).

PubMed

Hsieh, Yu-Shan; Hsu, Chin-Yuan

2013-08-01

Trophocytes and fat cells of queen honeybees have been used for delayed cellular senescence studies, but their oxidative stress and anti-oxidant enzyme activities with advancing age are unknown. In this study, we assayed reactive oxygen species (ROS) and anti-oxidant enzymes in the trophocytes and fat cells of young and old queens. Young queens had lower ROS levels, lower superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities, and higher thioredoxin reductase (TR) activity compared to old queens. These results show that oxidative stress and anti-oxidant enzyme activities in trophocytes and fat cells increase with advancing age in queens and suggest that an increase in oxidative stress and a consequent increase in stress defense mechanisms are associated with the longevity of queen honeybees.

Quantitative weight of evidence assessment of higher tier studies on the toxicity and risks of neonicotinoids in honeybees. 4. Thiamethoxam.

PubMed

Stephenson, Gladys L; Solomon, Keith R

2017-01-01

A quantitative weight of evidence (QWoE) methodology was used to assess several higher-tier studies on the effects of thiamethoxam (TMX) on honeybees. Assessment endpoints were population size and viability of commercially managed honeybee colonies and quantity of hive products. A higher-tier field toxicology study indicated a no-observed-adverse effect concentration (NOAEC) of 29.5 µg TMX/kg syrup, equivalent to an oral no-observed-adverse-effect-dose (NOAED) of 8.6 ng/bee/day for all responses measured. For exposures via deposition of dust, a conservative no-observed-adverse-effect-rate at the level of the colony was 0.1 g TMX/ha. There was minimal risk to honeybees from exposure to TMX via nectar and pollen from its use as a seed-treatment. For exposures via dust and dust/seed applications, there were no concentrations above the risk values for TMX in nectar and pollen. Although some risks were identified for potential exposures via guttation fluid, this route of exposure is incomplete; no apparent adverse effects were observed in field studies. For exposures via dust/seed and dust/foliar applications, few adverse effects were observed. Considering all lines of evidence, the quality of the studies included in this analysis was variable. However, the results of the studies were consistent and point to the same conclusion. The overall weight of evidence based on many studies indicates that TMX has no adverse effects on viability or survival of the colony. Thus, the overall conclusion is that the treatment of seeds with thiamethoxam, as currently used in good agricultural practices, does not present a significant risk to honeybees at the level of the colony.

Agrochemical synergism imposes higher risk to Neotropical bees than to honeybees

PubMed Central

Tomé, Hudson V. V.; Ramos, Gabryele S.; Araújo, Micaele F.; Santana, Weyder C.; Santos, Gil R.; Guedes, Raul Narciso C.; Maciel, Carlos D.; Newland, Philip L.

2017-01-01

Bees are key pollinators whose population numbers are declining, in part, owing to the effects of different stressors such as insecticides and fungicides. We have analysed the susceptibility of the Africanized honeybee, Apis mellifera, and the stingless bee, Partamona helleri, to commercial formulations of the insecticides deltamethrin and imidacloprid. The toxicity of fungicides based on thiophanate-methyl and chlorothalonil were investigated individually and in combination, and with the insecticides. Results showed that stingless bees were more susceptible to insecticides than honeybees. The commercial fungicides thiophanate-methyl or chlorothalonil caused low mortality, regardless of concentration; however, their combination was as toxic as imidacloprid to both species, and over 400-fold more toxic than deltamethrin for A. mellifera. There were highly synergistic effects on mortality caused by interactions in the mixture of imidacloprid and the fungicides thiophanate-methyl, chlorothalonil and the combined fungicide formulation in A. mellifera, and also to a lesser extent in P. helleri. By contrast, mixtures of the deltamethrin and the combined fungicide formulation induced high synergy in P. helleri, but had little effect on the mortality of A. mellifera. Differences in physiology and modes of action of agrochemicals are discussed as key factors underlying the differences in susceptibility to agrochemicals. PMID:28280585

Genetic diversity within honeybee colonies increases signal production by waggle-dancing foragers

PubMed Central

Mattila, Heather R; Burke, Kelly M; Seeley, Thomas D

2008-01-01

Recent work has demonstrated considerable benefits of intracolonial genetic diversity for the productivity of honeybee colonies: single-patriline colonies have depressed foraging rates, smaller food stores and slower weight gain relative to multiple-patriline colonies. We explored whether differences in the use of foraging-related communication behaviour (waggle dances and shaking signals) underlie differences in foraging effort of genetically diverse and genetically uniform colonies. We created three pairs of colonies; each pair had one colony headed by a multiply mated queen (inseminated by 15 drones) and one colony headed by a singly mated queen. For each pair, we monitored the production of foraging-related signals over the course of 3 days. Foragers in genetically diverse colonies had substantially more information available to them about food resources than foragers in uniform colonies. On average, in genetically diverse colonies compared with genetically uniform colonies, 36% more waggle dances were identified daily, dancers performed 62% more waggle runs per dance, foragers reported food discoveries that were farther from the nest and 91% more shaking signals were exchanged among workers each morning prior to foraging. Extreme polyandry by honeybee queens enhances the production of worker–worker communication signals that facilitate the swift discovery and exploitation of food resources. PMID:18198143

Blue colour preference in honeybees distracts visual attention for learning closed shapes.

PubMed

Morawetz, Linde; Svoboda, Alexander; Spaethe, Johannes; Dyer, Adrian G

2013-10-01

Spatial vision is an important cue for how honeybees (Apis mellifera) find flowers, and previous work has suggested that spatial learning in free-flying bees is exclusively mediated by achromatic input to the green photoreceptor channel. However, some data suggested that bees may be able to use alternative channels for shape processing, and recent work shows conditioning type and training length can significantly influence bee learning and cue use. We thus tested the honeybees' ability to discriminate between two closed shapes considering either absolute or differential conditioning, and using eight stimuli differing in their spectral characteristics. Consistent with previous work, green contrast enabled reliable shape learning for both types of conditioning, but surprisingly, we found that bees trained with appetitive-aversive differential conditioning could additionally use colour and/or UV contrast to enable shape discrimination. Interestingly, we found that a high blue contrast initially interferes with bee shape learning, probably due to the bees innate preference for blue colours, but with increasing experience bees can learn a variety of spectral and/or colour cues to facilitate spatial learning. Thus, the relationship between bee pollinators and the spatial and spectral cues that they use to find rewarding flowers appears to be a more rich visual environment than previously thought.

In-Depth N-Glycosylation Reveals Species-Specific Modifications and Functions of the Royal Jelly Protein from Western (Apis mellifera) and Eastern Honeybees (Apis cerana).

PubMed

Feng, Mao; Fang, Yu; Han, Bin; Xu, Xiang; Fan, Pei; Hao, Yue; Qi, Yuping; Hu, Han; Huo, Xinmei; Meng, Lifeng; Wu, Bin; Li, Jianke

2015-12-04

Royal jelly (RJ), secreted by honeybee workers, plays diverse roles as nutrients and defense agents for honeybee biology and human health. Despite being reported to be glycoproteins, the glycosylation characterization and functionality of RJ proteins in different honeybee species are largely unknown. An in-depth N-glycoproteome analysis and functional assay of RJ produced by Apis mellifera lingustica (Aml) and Apis cerana cerana (Acc) were conducted. RJ produced by Aml yielded 80 nonredundant N-glycoproteins carrying 190 glycosites, of which 23 novel proteins harboring 35 glycosites were identified. For Acc, all 43 proteins glycosylated at 138 glycosites were reported for the first time. Proteins with distinct N-glycoproteomic characteristics in terms of glycoprotein species, number of N-glycosylated sites, glycosylation motif, abundance level of glycoproteins, and N-glycosites were observed in this two RJ samples. The fact that the low inhibitory efficiency of N-glycosylated major royal jelly protein 2 (MRJP2) against Paenibacillus larvae (P. larvae) and the absence of antibacterial related glycosylated apidaecin, hymenoptaecin, and peritrophic matrix in the Aml RJ compared to Acc reveal the mechanism for why the Aml larvae are susceptible to P. larvae, the causative agent of a fatal brood disease (American foulbrood, AFB). The observed antihypertension activity of N-glycosylated MRJP1 in two RJ samples and a stronger activity found in Acc than in Aml reveal that specific RJ protein and modification are potentially useful for the treatment of hypertensive disease for humans. Our data gain novel understanding that the western and eastern bees have evolved species-specific strategies of glycosylation to fine-tune protein activity for optimizing molecular function as nutrients and immune agents for the good of honeybee and influence on the health promoting activity for human as well. This serves as a valuable resource for the targeted probing of the biological

Thiamethoxam: Assessing flight activity of honeybees foraging on treated oilseed rape using radio frequency identification technology.

PubMed

Thompson, Helen; Coulson, Mike; Ruddle, Natalie; Wilkins, Selwyn; Harkin, Sarah

2016-02-01

The present study was designed to assess homing behavior of bees foraging on winter oilseed rape grown from seed treated with thiamethoxam (as Cruiser OSR), with 1 field drilled with thiamethoxam-treated seed and 2 control fields drilled with fungicide-only-treated seed. Twelve honeybee colonies were used per treatment group, 4 each located at the field edge (on-field site), at approximately 500 m and 1000 m from the field. A total of nearly 300 newly emerged bees per colony were fitted (tagged) with Mic3 radio frequency identification (RFID) transponders and introduced into each of the 36 study hives. The RFID readers fitted to the entrances of the test colonies were used to monitor the activity of the tagged bees for the duration of the 5-wk flowering period of the crop. These activity data were analyzed to assess any impact on flight activity of bees foraging on the treated compared with untreated crops. Honeybees were seen to be actively foraging within all 3 treatment groups during the exposure period. The data for the more than 3000 RFID-tagged bees and more than 90 000 foraging flights monitored throughout the exposure phase for the study follow the same trends across the treatment and controls and at each of the 3 apiary distances, indicating that there were no effects from foraging on the treated crop. Under the experimental conditions, there was no effect of foraging on thiamethoxam-treated oilseed rape on honeybee flight activity or on their ability to return to the hive. © 2015 SETAC.

Sex and Caste-Specific Variation in Compound Eye Morphology of Five Honeybee Species

PubMed Central

Streinzer, Martin; Brockmann, Axel; Nagaraja, Narayanappa; Spaethe, Johannes

2013-01-01

Ranging from dwarfs to giants, the species of honeybees show remarkable differences in body size that have placed evolutionary constrains on the size of sensory organs and the brain. Colonies comprise three adult phenotypes, drones and two female castes, the reproductive queen and sterile workers. The phenotypes differ with respect to tasks and thus selection pressures which additionally constrain the shape of sensory systems. In a first step to explore the variability and interaction between species size-limitations and sex and caste-specific selection pressures in sensory and neural structures in honeybees, we compared eye size, ommatidia number and distribution of facet lens diameters in drones, queens and workers of five species (Apis andreniformis, A. florea, A. dorsata, A. mellifera, A. cerana). In these species, male and female eyes show a consistent sex-specific organization with respect to eye size and regional specialization of facet diameters. Drones possess distinctly enlarged eyes with large dorsal facets. Aside from these general patterns, we found signs of unique adaptations in eyes of A. florea and A. dorsata drones. In both species, drone eyes are disproportionately enlarged. In A. dorsata the increased eye size results from enlarged facets, a likely adaptation to crepuscular mating flights. In contrast, the relative enlargement of A. florea drone eyes results from an increase in ommatidia number, suggesting strong selection for high spatial resolution. Comparison of eye morphology and published mating flight times indicates a correlation between overall light sensitivity and species-specific mating flight times. The correlation suggests an important role of ambient light intensities in the regulation of species-specific mating flight times and the evolution of the visual system. Our study further deepens insights into visual adaptations within the genus Apis and opens up future perspectives for research to better understand the timing mechanisms

Steroid Hormone (20-Hydroxyecdysone) Modulates the Acquisition of Aversive Olfactory Memories in Pollen Forager Honeybees

ERIC Educational Resources Information Center

Geddes, Lisa H.; McQuillan, H. James; Aiken, Alastair; Vergoz, Vanina; Mercer, Alison R.

2013-01-01

Here, we examine effects of the steroid hormone, 20-hydroxyecdysone (20-E), on associative olfactory learning in the honeybee, "Apis mellifera." 20-E impaired the bees' ability to associate odors with punishment during aversive conditioning, but did not interfere with their ability to associate odors with a food reward (appetitive…

Involvement of Phosphorylated "Apis Mellifera" CREB in Gating a Honeybee's Behavioral Response to an External Stimulus

ERIC Educational Resources Information Center

Gehring, Katrin B.; Heufelder, Karin; Feige, Janina; Bauer, Paul; Dyck, Yan; Ehrhardt, Lea; Kühnemund, Johannes; Bergmann, Anja; Göbel, Josefine; Isecke, Marlene; Eisenhardt, Dorothea

2016-01-01

The transcription factor cAMP-response element-binding protein (CREB) is involved in neuronal plasticity. Phosphorylation activates CREB and an increased level of phosphorylated CREB is regarded as an indicator of CREB-dependent transcriptional activation. In honeybees ("Apis mellifera") we recently demonstrated a particular high…

Parallel processing via a dual olfactory pathway in the honeybee.

PubMed

Brill, Martin F; Rosenbaum, Tobias; Reus, Isabelle; Kleineidam, Christoph J; Nawrot, Martin P; Rössler, Wolfgang

2013-02-06

In their natural environment, animals face complex and highly dynamic olfactory input. Thus vertebrates as well as invertebrates require fast and reliable processing of olfactory information. Parallel processing has been shown to improve processing speed and power in other sensory systems and is characterized by extraction of different stimulus parameters along parallel sensory information streams. Honeybees possess an elaborate olfactory system with unique neuronal architecture: a dual olfactory pathway comprising a medial projection-neuron (PN) antennal lobe (AL) protocerebral output tract (m-APT) and a lateral PN AL output tract (l-APT) connecting the olfactory lobes with higher-order brain centers. We asked whether this neuronal architecture serves parallel processing and employed a novel technique for simultaneous multiunit recordings from both tracts. The results revealed response profiles from a high number of PNs of both tracts to floral, pheromonal, and biologically relevant odor mixtures tested over multiple trials. PNs from both tracts responded to all tested odors, but with different characteristics indicating parallel processing of similar odors. Both PN tracts were activated by widely overlapping response profiles, which is a requirement for parallel processing. The l-APT PNs had broad response profiles suggesting generalized coding properties, whereas the responses of m-APT PNs were comparatively weaker and less frequent, indicating higher odor specificity. Comparison of response latencies within and across tracts revealed odor-dependent latencies. We suggest that parallel processing via the honeybee dual olfactory pathway provides enhanced odor processing capabilities serving sophisticated odor perception and olfactory demands associated with a complex olfactory world of this social insect.

Effect of honeybee broods (queen-bee different lineage) moving on disease development at various beehive types and allergy reaction cause in humans.

PubMed

Tucak, Zvonimir; Periskić, Marin

2005-06-01

The change of the location of the beehives on the diverse honeyfull pastures is the usual apiarists activity in the Republic of Croatia. The main reasons are the climatic and vegetation diversity, and richness of the floral composition, with numerous bee forage plants. Our study aimed to detect consequences of honeybee broods (Queen-bee of different lineage) moving, from one habitat to another at various type of beehives. The Alberti-Znidersic (AZ), Langstroth-Root (LR) and Dadant-Blatt (DB) beehive types, constructed of (lime-tree), have been used. After the bee forage on the Oilseed Rape in the beginning of April, the honeybee brood has been veterinary inspected (based on the Law of animal health protection in the Republic of Croatia) for varrosis, nosemosis and American foulbrood diseases. The same procedure was done after bee forage (False acacia) at the end of May. All of the honeybees belong to the European race Apis mellifera carnica. The results of the study pointed out that different beehive types and the Queen-bee lineage (natural and selected) affect development of disease inside the honeybee brood, during the relocation and change from one dominant bee forage plants to another. Certain allergy reactions occurring in people can be caused by the pollen of some honefull plants such as birch, grasses, ragweed, goldenrod and hazel. Such cases are also included in our investigations. Beekeepers and nature lovers sensitive to pollen allergens of some honeyfull plants should, in some calendar period, avoid ecological milieu with such plants.

Proteome and phosphoproteome analysis of honeybee (Apis mellifera) venom collected from electrical stimulation and manual extraction of the venom gland

PubMed Central

2013-01-01

Background Honeybee venom is a complicated defensive toxin that has a wide range of pharmacologically active compounds. Some of these compounds are useful for human therapeutics. There are two major forms of honeybee venom used in pharmacological applications: manually (or reservoir disrupting) extracted glandular venom (GV), and venom extracted through the use of electrical stimulation (ESV). A proteome comparison of these two venom forms and an understanding of the phosphorylation status of ESV, are still very limited. Here, the proteomes of GV and ESV were compared using both gel-based and gel-free proteomics approaches and the phosphoproteome of ESV was determined through the use of TiO2 enrichment. Results Of the 43 proteins identified in GV, < 40% were venom toxins, and > 60% of the proteins were non-toxic proteins resulting from contamination by gland tissue damage during extraction and bee death. Of the 17 proteins identified in ESV, 14 proteins (>80%) were venom toxic proteins and most of them were found in higher abundance than in GV. Moreover, two novel proteins (dehydrogenase/reductase SDR family member 11-like and histone H2B.3-like) and three novel phosphorylation sites (icarapin (S43), phospholipase A-2 (T145), and apamin (T23)) were identified. Conclusions Our data demonstrate that venom extracted manually is different from venom extracted using ESV, and these differences may be important in their use as pharmacological agents. ESV may be more efficient than GV as a potential pharmacological source because of its higher venom protein content, production efficiency, and without the need to kill honeybee. The three newly identified phosphorylated venom proteins in ESV may elicit a different immune response through the specific recognition of antigenic determinants. The two novel venom proteins extend our proteome coverage of honeybee venom. PMID:24199871

Effect of Temperature on the Biotic Potential of Honeybee Microsporidia▿

PubMed Central

Martín-Hernández, Raquel; Meana, Aránzazu; García-Palencia, Pilar; Marín, Pilar; Botías, Cristina; Garrido-Bailón, Encarna; Barrios, Laura; Higes, Mariano

2009-01-01

The biological cycle of Nosema spp. in honeybees depends on temperature. When expressed as total spore counts per day after infection, the biotic potentials of Nosema apis and N. ceranae at 33°C were similar, but a higher proportion of immature stages of N. ceranae than of N. apis were seen. At 25 and 37°C, the biotic potential of N. ceranae was higher than that of N. apis. The better adaptation of N. ceranae to complete its endogenous cycle at different temperatures clearly supports the observation of the different epidemiological patterns. PMID:19233948

Acute axonal polyneuropathy following honey-bee sting: a case report.

PubMed

Saini, Arushi Gahlot; Sankhyan, Naveen; Suthar, Renu; Singhi, Pratibha

2014-05-01

Hymenoptera stings lead to a myriad of neurologic manifestations by the mechanism of immediate or delayed hypersensitivity reactions. The more common form of polyneuropathy associated with these stings is the acute inflammatory demyelinating type. We describe a 6-year-old girl, who developed progressive, symmetrical, ascending weakness within 3 days after a bee sting. Serial nerve conduction studies confirmed acute, motor-predominant axonal polyneuropathy. Use of intravenous immunoglobulin induced halt of progression, prompt stabilization and a gradual recovery. This case highlights that even a single honey-bee sting can result in acute-onset axonal variety of polyneuropathy in children.

Honeybee males use highly concentrated nectar as fuel for mating flights.

PubMed

Hayashi, Masaki; Nakamura, Jun; Sasaki, Ken; Harano, Ken-Ichi

Honeybees use nectar held in the crop as their main source of energy for flight but the mass of the crop nectar load may be a cost burden. This study investigated whether males of the honeybee Apis mellifera adjust their nectar fuel load and concentration to enhance the success of mating flights. When the crop content was compared between males staying in the hive and those departing, the latter group had the larger volume (median, 5.0μl; range, 0.0-17.8μl) and higher concentration (median, 71.6%; range, 49.0%-77.6%), indicating that departing males load concentrated nectar as fuel before mating flights. Moreover, the crop nectar concentration was significantly higher in departing males than in departing workers. These results suggest that concentrated nectar is advantageous to males because it provides more sugar for energy at lower mass and secures longer or more effective mating flights for higher chance of reproductive success. No significant effect of age was detected in crop volume, and concentration and amount of dissolved sugars in the crop content. In addition, laboratory experiments showed that males had only about 5μl of nectar in the crop soon after feeding, irrespective of fed volume (5-15μl), suggesting they do not hold much nectar in the crop but send it rapidly to the midgut, unlike workers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Widespread exploitation of the honeybee by early Neolithic farmers.

PubMed

Roffet-Salque, Mélanie; Regert, Martine; Evershed, Richard P; Outram, Alan K; Cramp, Lucy J E; Decavallas, Orestes; Dunne, Julie; Gerbault, Pascale; Mileto, Simona; Mirabaud, Sigrid; Pääkkönen, Mirva; Smyth, Jessica; Šoberl, Lucija; Whelton, Helen L; Alday-Ruiz, Alfonso; Asplund, Henrik; Bartkowiak, Marta; Bayer-Niemeier, Eva; Belhouchet, Lotfi; Bernardini, Federico; Budja, Mihael; Cooney, Gabriel; Cubas, Miriam; Danaher, Ed M; Diniz, Mariana; Domboróczki, László; Fabbri, Cristina; González-Urquijo, Jesus E; Guilaine, Jean; Hachi, Slimane; Hartwell, Barrie N; Hofmann, Daniela; Hohle, Isabel; Ibáñez, Juan J; Karul, Necmi; Kherbouche, Farid; Kiely, Jacinta; Kotsakis, Kostas; Lueth, Friedrich; Mallory, James P; Manen, Claire; Marciniak, Arkadiusz; Maurice-Chabard, Brigitte; Mc Gonigle, Martin A; Mulazzani, Simone; Özdoğan, Mehmet; Perić, Olga S; Perić, Slaviša R; Petrasch, Jörg; Pétrequin, Anne-Marie; Pétrequin, Pierre; Poensgen, Ulrike; Pollard, C Joshua; Poplin, François; Radi, Giovanna; Stadler, Peter; Stäuble, Harald; Tasić, Nenad; Urem-Kotsou, Dushka; Vuković, Jasna B; Walsh, Fintan; Whittle, Alasdair; Wolfram, Sabine; Zapata-Peña, Lydia; Zoughlami, Jamel

2015-11-12

The pressures on honeybee (Apis mellifera) populations, resulting from threats by modern pesticides, parasites, predators and diseases, have raised awareness of the economic importance and critical role this insect plays in agricultural societies across the globe. However, the association of humans with A. mellifera predates post-industrial-revolution agriculture, as evidenced by the widespread presence of ancient Egyptian bee iconography dating to the Old Kingdom (approximately 2400 BC). There are also indications of Stone Age people harvesting bee products; for example, honey hunting is interpreted from rock art in a prehistoric Holocene context and a beeswax find in a pre-agriculturalist site. However, when and where the regular association of A. mellifera with agriculturalists emerged is unknown. One of the major products of A. mellifera is beeswax, which is composed of a complex suite of lipids including n-alkanes, n-alkanoic acids and fatty acyl wax esters. The composition is highly constant as it is determined genetically through the insect's biochemistry. Thus, the chemical 'fingerprint' of beeswax provides a reliable basis for detecting this commodity in organic residues preserved at archaeological sites, which we now use to trace the exploitation by humans of A. mellifera temporally and spatially. Here we present secure identifications of beeswax in lipid residues preserved in pottery vessels of Neolithic Old World farmers. The geographical range of bee product exploitation is traced in Neolithic Europe, the Near East and North Africa, providing the palaeoecological range of honeybees during prehistory. Temporally, we demonstrate that bee products were exploited continuously, and probably extensively in some regions, at least from the seventh millennium cal BC, likely fulfilling a variety of technological and cultural functions. The close association of A. mellifera with Neolithic farming communities dates to the early onset of agriculture and may provide

Immune and clinical response to honeybee venom in beekeepers.

PubMed

Matysiak, Jan; Matysiak, Joanna; Bręborowicz, Anna; Kycler, Zdzisława; Dereziński, Paweł; Kokot, Zenon J

2016-01-01

The aim of the study was to assess immune response to honeybee venom in relation to the degree of exposure, time after a sting and clinical symptoms. Fifty-four volunteers were divided into 2 groups: beekeepers and a control group. The serum levels of total IgE (tIgE), bee venom-specific IgE (venom sIgE), phospholipase A2-specific IgE (phospholipase A2 sIgE), tryptase and venom-specific IgG4 (venom sIgG4) were determined. In beekeepers, diagnostic tests were performed within 3 hours following a sting and were repeated after a minimum of 6 weeks from the last sting. In individuals from the control group, the tests were performed only once, without a sting. The tests showed significant differences in venom sIgE (beekeepers' median = 0.34 kUA/l, control group median = 0.29 kUA/l), baseline serum tryptase (beekeepers' median = 4.25 µg/l, control group median = 2.74 µg/l) and sIgG4 (beekeepers' median = 21.2 mgA/l, control group median = 0.14 mgA/l), confirming higher levels of the tested substances in the beekeepers than in the control group. A significant positive correlation was observed between phospholipase A2 sIgE concentration and severity of clinical symptoms after a sting in the group of beekeepers. It was also demonstrated that the clinical symptoms after a sting became less severe with increasing age of the beekeepers. The differences in the immune response to a bee sting between the beekeepers and individuals not exposed to bees were probably due to the high exposure of the beekeepers to honeybee venom allergens. This may suggest a different approach to the bee venom allergy diagnostic tests in this occupational group.

A Test of Transitive Inferences in Free-Flying Honeybees: Unsuccessful Performance Due to Memory Constraints

ERIC Educational Resources Information Center

Benard, Julie; Giurfa, Martin

2004-01-01

We asked whether honeybees, "Apis mellifera," could solve a transitive inference problem. Individual free-flying bees were conditioned with four overlapping premise pairs of five visual patterns in a multiple discrimination task (A+ vs. B-, B+ vs. C-, C+ vs. D-, D+ vs. E-, where + and - indicate sucrose reward or absence of it,…

Decision-making in honeybee swarms based on quality and distance information of candidate nest sites.

PubMed

Laomettachit, Teeraphan; Termsaithong, Teerasit; Sae-Tang, Anuwat; Duangphakdee, Orawan

2015-01-07

In the nest-site selection process of honeybee swarms, an individual bee performs a waggle dance to communicate information about direction, quality, and distance of a discovered site to other bees at the swarm. Initially, different groups of bees dance to represent different potential sites, but eventually the swarm usually reaches an agreement for only one site. Here, we model the nest-site selection process in honeybee swarms of Apis mellifera and show how the swarms make adaptive decisions based on a trade-off between the quality and distance to candidate nest sites. We use bifurcation analysis and stochastic simulations to reveal that the swarm's site distance preference is moderate>near>far when the swarms choose between low quality sites. However, the distance preference becomes near>moderate>far when the swarms choose between high quality sites. Our simulations also indicate that swarms with large population size prefer nearer sites and, in addition, are more adaptive at making decisions based on available information compared to swarms with smaller population size. Copyright © 2014 Elsevier Ltd. All rights reserved.

Different bees, different needs: how nest-site requirements have shaped the decision-making processes in homeless honeybees (Apis spp.).

PubMed

Beekman, Madeleine; Oldroyd, Benjamin P

2018-05-19

During reproductive swarming, a honeybee swarm needs to decide on a new nest site and then move to the chosen site collectively. Most studies of swarming and nest-site selection are based on one species, Apis mellifera Natural colonies of A. mellifera live in tree cavities. The quality of the cavity is critical to the survival of a swarm. Other honeybee species nest in the open, and have less strict nest-site requirements, such as the open-nesting dwarf honeybee Apis florea Apis florea builds a nest comprised of a single comb suspended from a twig. For a cavity-nesting species, there is only a limited number of potential nest sites that can be located by a swarm, because suitable sites are scarce. By contrast, for an open-nesting species, there is an abundance of equally suitable twigs. While the decision-making process of cavity-nesting bees is geared towards selecting the best site possible, open-nesting species need to coordinate collective movement towards areas with potential nest sites. Here, we argue that the nest-site selection processes of A. florea and A. mellifera have been shaped by each species' specific nest-site requirements. Both species use the same behavioural algorithm, tuned to allow each species to solve their species-specific problem.This article is part of the theme issue 'Collective movement ecology'. © 2018 The Author(s).

The cyanobacterial neurotoxin beta-N-methylamino-L-alanine (BMAA) induces neuronal and behavioral changes in honeybees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okle, Oliver, E-mail: oliver.okle@uni-konstanz.de; Rath, Lisa; Galizia, C. Giovanni

The cyanobacterially produced neurotoxin beta-N-methylamino-L-alanine (BMAA) is thought to induce amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC)-like symptoms. However, its mechanism of action and its pathway of intoxication are yet unknown. In vivo animal models suitable for investigating the neurotoxic effect of BMAA with applicability to the human are scarce. Hence, we used the honeybee (Apis mellifera) since its nervous system is relatively simple, yet having cognitive capabilities. Bees fed with BMAA-spiked sugar water had an increased mortality rate and a reduced ability to learn odors in a classical conditioning paradigm. Using {sup 14}C-BMAA we demonstrated that BMAA is biologically availablemore » to the bee, and is found in the head, thorax and abdomen with little to no excretion. BMAA is also transferred from one bee to the next via trophallaxis resulting in an exposure of the whole beehive. BMAA bath application directly onto the brain leads to an altered Ca{sup 2+} homeostasis and to generation of reactive oxygen species. These behavioral and physiological observations suggest that BMAA may have effects on bee brains similar to those assumed to occur in humans. Therefore the bee could serve as a surrogate model system for investigating the neurological effects of BMAA. - Highlights: • Investigating of neurotoxic effects of BMAA in honeybees • BMAA impairs ALS markers (ROS, Ca{sup 2+}, learning, memory, odor) in bees. • A method for the observation of ROS development in living bees brain was established. • Honeybees are a suitable model to explore neurodegenerative processes. • Neurotoxic BMAA can be spread in bee populations by trophallaxis.« less

Industrial apiculture in the Jordan valley during Biblical times with Anatolian honeybees

PubMed Central

Bloch, Guy; Francoy, Tiago M.; Wachtel, Ido; Panitz-Cohen, Nava; Fuchs, Stefan; Mazar, Amihai

2010-01-01

Although texts and wall paintings suggest that bees were kept in the Ancient Near East for the production of precious wax and honey, archaeological evidence for beekeeping has never been found. The Biblical term “honey” commonly was interpreted as the sweet product of fruits, such as dates and figs. The recent discovery of unfired clay cylinders similar to traditional hives still used in the Near East at the site of Tel Reov in the Jordan valley in northern Israel suggests that a large-scale apiary was located inside the town, dating to the 10th–early 9th centuries B.C.E. This paper reports the discovery of remains of honeybee workers, drones, pupae, and larvae inside these hives. The exceptional preservation of these remains provides unequivocal identification of the clay cylinders as the most ancient beehives yet found. Morphometric analyses indicate that these bees differ from the local subspecies Apis mellifera syriaca and from all subspecies other than A. m. anatoliaca, which presently resides in parts of Turkey. This finding suggests either that the Western honeybee subspecies distribution has undergone rapid change during the last 3,000 years or that the ancient inhabitants of Tel Reov imported bees superior to the local bees in terms of their milder temper and improved honey yield. PMID:20534519

Industrial apiculture in the Jordan valley during Biblical times with Anatolian honeybees.

PubMed

Bloch, Guy; Francoy, Tiago M; Wachtel, Ido; Panitz-Cohen, Nava; Fuchs, Stefan; Mazar, Amihai

2010-06-22

Although texts and wall paintings suggest that bees were kept in the Ancient Near East for the production of precious wax and honey, archaeological evidence for beekeeping has never been found. The Biblical term "honey" commonly was interpreted as the sweet product of fruits, such as dates and figs. The recent discovery of unfired clay cylinders similar to traditional hives still used in the Near East at the site of Tel Re ov in the Jordan valley in northern Israel suggests that a large-scale apiary was located inside the town, dating to the 10th-early 9th centuries B.C.E. This paper reports the discovery of remains of honeybee workers, drones, pupae, and larvae inside these hives. The exceptional preservation of these remains provides unequivocal identification of the clay cylinders as the most ancient beehives yet found. Morphometric analyses indicate that these bees differ from the local subspecies Apis mellifera syriaca and from all subspecies other than A. m. anatoliaca, which presently resides in parts of Turkey. This finding suggests either that the Western honeybee subspecies distribution has undergone rapid change during the last 3,000 years or that the ancient inhabitants of Tel Re ov imported bees superior to the local bees in terms of their milder temper and improved honey yield.

Addressing the diversity of the honeybee gut symbiont Gilliamella: description of Gilliamella apis sp. nov., isolated from the gut of honeybees (Apis mellifera).

PubMed

Ludvigsen, Jane; Porcellato, Davide; Amdam, Gro V; Rudi, Knut

2018-05-01

The gut microbiota of honeybees (Apis) and bumblebees (Bombus) include the symbiotic bacterial genus Gilliamella. This genus shows a high degree of functional and genomic diversity and separates into distinct lineages. Gilliamella apicola wkB1 T , which was isolated from Apis, was the first species to be described. Recently four new species, isolated from Bombus, were identified. In this paper, we compare several genomes/strains from previous studies spanning this diversity, which gives insight into the phylogenetic relationship among different Gilliamella species. We show that one lineage, isolated only from Apis, is different from other gilliamellas described, based on average nucleotide identity calculation (about 80 %) and phenotypic characterizations. We propose the new species name for this lineage: Gilliamella apis sp. nov. We present the characterization of the type strain NO3 T (=DSM 105629 T =LMG 30293 T ), a strain isolated from the Western honeybee Apis mellifera, which clusters within this lineage. Cells of strain NO3 T grow best in a microaerophilic atmosphere with enhanced CO2 levels at 36 °C and pH 7.0-7.5. Cells also grow well in anaerobic conditions, but not in aerobic conditions. Cells are approximately 1 µm in length and rod-shaped, and the genomic G+C content is 34.7 mol%. Differential characteristics between strain NO3 T and the different type strains of Gilliamella were revealed based on API kit tests and genomic content comparisons. The main respiratory quinone of strain NO3 T was ubiquinone-8, and the predominant fatty acids were C18 : 1ω7c/C18 : 1ω6c, C16 : 0, consistent with the genus Gilliamella.

Flight restriction prevents associative learning deficits but not changes in brain protein-adduct formation during honeybee ageing.

PubMed

Tolfsen, Christina C; Baker, Nicholas; Kreibich, Claus; Amdam, Gro V

2011-04-15

Honeybees (Apis mellifera) senesce within 2 weeks after they discontinue nest tasks in favour of foraging. Foraging involves metabolically demanding flight, which in houseflies (Musca domestica) and fruit flies (Drosophila melanogaster) is associated with markers of ageing such as increased mortality and accumulation of oxidative damage. The role of flight in honeybee ageing is incompletely understood. We assessed relationships between honeybee flight activity and ageing by simulating rain that confined foragers to their colonies most of the day. After 15 days on average, flight-restricted foragers were compared with bees with normal (free) flight: one group that foraged for ∼15 days and two additional control groups, for flight duration and chronological age, that foraged for ∼5 days. Free flight over 15 days on average resulted in impaired associative learning ability. In contrast, flight-restricted foragers did as well in learning as bees that foraged for 5 days on average. This negative effect of flight activity was not influenced by chronological age or gustatory responsiveness, a measure of the bees' motivation to learn. Contrasting their intact learning ability, flight-restricted bees accrued the most oxidative brain damage as indicated by malondialdehyde protein adduct levels in crude cytosolic fractions. Concentrations of mono- and poly-ubiquitinated brain proteins were equal between the groups, whereas differences in total protein amounts suggested changes in brain protein metabolism connected to forager age, but not flight. We propose that intense flight is causal to brain deficits in aged bees, and that oxidative protein damage is unlikely to be the underlying mechanism.

Flight restriction prevents associative learning deficits but not changes in brain protein-adduct formation during honeybee ageing

PubMed Central

Tolfsen, Christina C.; Baker, Nicholas; Kreibich, Claus; Amdam, Gro V.

2011-01-01

SUMMARY Honeybees (Apis mellifera) senesce within 2 weeks after they discontinue nest tasks in favour of foraging. Foraging involves metabolically demanding flight, which in houseflies (Musca domestica) and fruit flies (Drosophila melanogaster) is associated with markers of ageing such as increased mortality and accumulation of oxidative damage. The role of flight in honeybee ageing is incompletely understood. We assessed relationships between honeybee flight activity and ageing by simulating rain that confined foragers to their colonies most of the day. After 15 days on average, flight-restricted foragers were compared with bees with normal (free) flight: one group that foraged for ∼15 days and two additional control groups, for flight duration and chronological age, that foraged for ∼5 days. Free flight over 15 days on average resulted in impaired associative learning ability. In contrast, flight-restricted foragers did as well in learning as bees that foraged for 5 days on average. This negative effect of flight activity was not influenced by chronological age or gustatory responsiveness, a measure of the bees' motivation to learn. Contrasting their intact learning ability, flight-restricted bees accrued the most oxidative brain damage as indicated by malondialdehyde protein adduct levels in crude cytosolic fractions. Concentrations of mono- and poly-ubiquitinated brain proteins were equal between the groups, whereas differences in total protein amounts suggested changes in brain protein metabolism connected to forager age, but not flight. We propose that intense flight is causal to brain deficits in aged bees, and that oxidative protein damage is unlikely to be the underlying mechanism. PMID:21430210

Amino acid content and nectar choice by forager honeybees (Apis mellifera L.).

PubMed

Bertazzini, Michele; Medrzycki, Piotr; Bortolotti, Laura; Maistrello, Lara; Forlani, Giuseppe

2010-06-01

Dual choice feeding tests were performed to determine a preference of forager honeybees for specific amino acids. Artificial nectar containing proline was preferred over those containing only sugars. Nectar containing alanine was preferred on the first day, but preference was no longer significant thereafter. On the contrary, a negative response was found for serine. When the bees were given the choice between two nectars enriched with different compounds, proline was preferred above both alanine and serine, and alanine above serine.

Duration of the unconditioned stimulus in appetitive conditioning of honeybees differentially impacts learning, long-term memory strength, and the underlying protein synthesis

PubMed Central

Marter, Kathrin; Grauel, M. Katharina; Lewa, Carmen; Morgenstern, Laura; Buckemüller, Christina; Heufelder, Karin; Ganz, Marion

2014-01-01

This study examines the role of stimulus duration in learning and memory formation of honeybees (Apis mellifera). In classical appetitive conditioning honeybees learn the association between an initially neutral, conditioned stimulus (CS) and the occurrence of a meaningful stimulus, the unconditioned stimulus (US). Thereby the CS becomes a predictor for the US eliciting a conditioned response (CR). Here we study the role of US duration in classical conditioning by examining honeybees conditioned with different US durations. We quantify the CR during acquisition, memory retention, and extinction of the early long-term memory (eLTM), and examine the molecular mechanisms of eLTM by interfering with protein synthesis. We find that the US duration affects neither the probability nor the strength of the CR during acquisition, eLTM retention, and extinction 24 h after conditioning. However, we find that the resistance to extinction 24 h after conditioning is susceptible to protein synthesis inhibition depending on the US duration. We conclude that the US duration does not affect the predictability of the US but modulates the protein synthesis underlying the eLTM's strength. Thus, the US duration differentially impacts learning, eLTM strength, and its underlying protein synthesis. PMID:25403456

High order neural correlates of social behavior in the honeybee brain.

PubMed

Duer, Aron; Paffhausen, Benjamin H; Menzel, Randolf

2015-10-30

Honeybees are well established models of neural correlates of sensory function, learning and memory formation. Here we report a novel approach allowing to record high-order mushroom body-extrinsic interneurons in the brain of worker bees within a functional colony. New method The use of two 100 cm long twisted copper electrodes allowed recording of up to four units of mushroom body-extrinsic neurons simultaneously for up to 24h in animals moving freely between members of the colony. Every worker, including the recorded bee, hatched in the experimental environment. The group consisted of 200 animals in average. Animals explored different regions of the comb and interacted with other colony members. The activities of the units were not selective for locations on the comb, body directions with respect to gravity and olfactory signals on the comb, or different social interactions. However, combinations of these parameters defined neural activity in a unit-specific way. In addition, units recorded from the same animal co-varied according to unknown factors. Comparison with existing method(s): All electrophysiological studies with honey bees were performed so far on constrained animals outside their natural behavioral contexts. Yet no neuronal correlates were measured in a social context. Free mobility of recoded insects over a range of a quarter square meter allows addressing questions concerning neural correlates of social communication, planning of tasks within the colony and attention-like processes. The method makes it possible to study neural correlates of social behavior in a near-natural setting within the honeybee colony. Copyright © 2015 Elsevier B.V. All rights reserved.

Honeybee (Apis cerana) foraging responses to the toxic honey of Tripterygium hypoglaucum (Celastraceae): changing threshold of nectar acceptability.

PubMed

Tan, K; Guo, Y H; Nicolson, S W; Radloff, S E; Song, Q S; Hepburn, H R

2007-12-01

To investigate honeybee foraging responses to toxic nectar, honey was collected from Apis cerana colonies in the Yaoan county of Yunnan Province, China, during June, when flowers of Tripterygium hypoglaucum were the main nectar source available. Pollen analysis confirmed the origin of the honey, and high-performance liquid chromatography showed the prominent component triptolide to be present at a concentration of 0.61 mug/g +/- 0.11 SD. In cage tests that used young adult worker bees, significantly more of those provided with a diet of T. hypoglaucum honey mixed with sugar powder (1:1) died within 6 d (68.3%) compared to control groups provided with normal honey mixed with sugar powder (15.8%). Honeybees were trained to visit feeders that contained honey of T. hypoglaucum (toxic honey) as the test group and honey of Vicia sativa or Elsholtzia ciliata as control groups (all honeys diluted 1:3 with water). Bees preferred the feeders with normal honey to those with toxic honey, as shown by significantly higher visiting frequencies and longer imbibition times. However, when the feeder of normal honey was removed, leaving only honey of T. hypoglaucum, the foraging bees returned to the toxic honey after a few seconds of hesitation, and both visiting frequency and imbibition time increased to values previously recorded for normal honey. Toxic honey thus became acceptable to the bees in the absence of other nectar sources.

Quality versus quantity: Foraging decisions in the honeybee (Apis mellifera scutellata) feeding on wildflower nectar and fruit juice.

PubMed

Shackleton, Kyle; Balfour, Nicholas J; Al Toufailia, Hasan; Gaioski, Roberto; de Matos Barbosa, Marcela; Silva, Carina A de S; Bento, José M S; Alves, Denise A; Ratnieks, Francis L W

2016-10-01

Foraging animals must often decide among resources which vary in quality and quantity. Nectar is a resource that exists along a continuum of quality in terms of sugar concentration and is the primary energy source for bees. Alternative sugar sources exist, including fruit juice, which generally has lower energetic value than nectar. We observed many honeybees ( Apis mellifera scutellata ) foraging on juice from fallen guava ( Psidium guajava ) fruit near others foraging on nectar. To investigate whether fruit and nectar offered contrasting benefits of quality and quantity, we compared honeybee foraging performance on P. guajava fruit versus two wildflowers growing within 50 m, Richardia brasiliensis and Tridax procumbens . Bees gained weight significantly faster on fruit, 2.72 mg/min, than on either flower (0.17 and 0.12 mg/min, respectively). However, the crop sugar concentration of fruit foragers was significantly lower than for either flower (12.4% vs. 37.0% and 22.7%, respectively). Fruit foragers also spent the most time handling and the least time flying, suggesting that fruit juice was energetically inexpensive to collect. We interpret honeybee foraging decisions in the context of existing foraging models and consider how nest-patch distance may be a key factor for central place foragers choosing between resources of contrasting quality and quantity. We also discuss how dilute solutions, such as fruit juice, can help maintain colony sugar-water balance. These results show the benefits of feeding on resources with contrasting quality and quantity and that even low-quality resources have value.

Long-term exposure to antibiotics has caused accumulation of resistance determinants in the gut microbiota of honeybees.

PubMed

Tian, Baoyu; Fadhil, Nibal H; Powell, J Elijah; Kwong, Waldan K; Moran, Nancy A

2012-10-30

Antibiotic treatment can impact nontarget microbes, enriching the pool of resistance genes available to pathogens and altering community profiles of microbes beneficial to hosts. The gut microbiota of adult honeybees, a distinctive community dominated by eight bacterial species, provides an opportunity to examine evolutionary responses to long-term treatment with a single antibiotic. For decades, American beekeepers have routinely treated colonies with oxytetracycline for control of larval pathogens. Using a functional metagenomic screen of bacteria from Maryland bees, we detected a high incidence of tetracycline/oxytetracycline resistance. This resistance is attributable to known resistance loci for which nucleotide sequences and flanking mobility genes were nearly identical to those from human pathogens and from bacteria associated with farm animals. Surveys using diagnostic PCR and sequencing revealed that gut bacteria of honeybees from diverse localities in the United States harbor eight tetracycline resistance loci, including efflux pump genes (tetB, tetC, tetD, tetH, tetL, and tetY) and ribosome protection genes (tetM and tetW), often at high frequencies. Isolates of gut bacteria from Connecticut bees display high levels of tetracycline resistance. Resistance genes were ubiquitous in American samples, though rare in colonies unexposed for 25 years. In contrast, only three resistance loci, at low frequencies, occurred in samples from countries not using antibiotics in beekeeping and samples from wild bumblebees. Thus, long-term antibiotic treatment has caused the bee gut microbiota to accumulate resistance genes, drawn from a widespread pool of highly mobile loci characterized from pathogens and agricultural sites. We found that 50 years of using antibiotics in beekeeping in the United States has resulted in extensive tetracycline resistance in the gut microbiota. These bacteria, which form a distinctive community present in healthy honeybees worldwide, may

Social encapsulation of beetle parasites by Cape honeybee colonies (Apis mellifera capensis Esch.)

NASA Astrophysics Data System (ADS)

Neumann, P.; Pirk, C. W. W.; Hepburn, H. R.; Solbrig, A. J.; Ratnieks, F. L. W.; Elzen, P. J.; Baxter, J. R.

2001-05-01

Worker honeybees (Apis mellifera capensis) encapsulate the small hive beetle (Aethina tumida), a nest parasite, in propolis (tree resin collected by the bees). The encapsulation process lasts 1-4 days and the bees have a sophisticated guarding strategy for limiting the escape of beetles during encapsulation. Some encapsulated beetles died (4.9%) and a few escaped (1.6%). Encapsulation has probably evolved because the small hive beetle cannot easily be killed by the bees due to its hard exoskeleton and defensive behaviour.

Honeybee glucose oxidase—its expression in honeybee workers and comparative analyses of its content and H2O2-mediated antibacterial activity in natural honeys

NASA Astrophysics Data System (ADS)

Bucekova, Marcela; Valachova, Ivana; Kohutova, Lenka; Prochazka, Emanuel; Klaudiny, Jaroslav; Majtan, Juraj

2014-08-01

Antibacterial properties of honey largely depend on the accumulation of hydrogen peroxide (H2O2), which is generated by glucose oxidase (GOX)-mediated conversion of glucose in diluted honey. However, honeys exhibit considerable variation in their antibacterial activity. Therefore, the aim of the study was to identify the mechanism behind the variation in this activity and in the H2O2 content in honeys associated with the role of GOX in this process. Immunoblots and in situ hybridization analyses demonstrated that gox is solely expressed in the hypopharyngeal glands of worker bees performing various tasks and not in other glands or tissues. Real-time PCR with reference genes selected for worker heads shows that the gox expression progressively increases with ageing of the youngest bees and nurses and reached the highest values in processor bees. Immunoblot analysis of honey samples revealed that GOX is a regular honey component but its content significantly varied among honeys. Neither botanical source nor geographical origin of honeys affected the level of GOX suggesting that some other factors such as honeybee nutrition and/or genetic/epigenetic factors may take part in the observed variation. A strong correlation was found between the content of GOX and the level of generated H2O2 in honeys except honeydew honeys. Total antibacterial activity of most honey samples against Pseudomonas aeruginosa isolate significantly correlated with the H2O2 content. These results demonstrate that the level of GOX can significantly affect the total antibacterial activity of honey. They also support an idea that breeding of novel honeybee lines expressing higher amounts of GOX could help to increase the antibacterial efficacy of the hypopharyngeal gland secretion that could have positive influence on a resistance of colonies against bacterial pathogens.

Molecular Mechanisms Underlying Formation of Long-Term Reward Memories and Extinction Memories in the Honeybee ("Apis Mellifera")

ERIC Educational Resources Information Center

Eisenhardt, Dorothea

2014-01-01

The honeybee ("Apis mellifera") has long served as an invertebrate model organism for reward learning and memory research. Its capacity for learning and memory formation is rooted in the ecological need to efficiently collect nectar and pollen during summer to ensure survival of the hive during winter. Foraging bees learn to associate a…

Food to some, poison to others - honeybee royal jelly and its growth inhibiting effect on European Foulbrood bacteria.

PubMed

Vezeteu, Thomas V; Bobiş, Otilia; Moritz, Robin F A; Buttstedt, Anja

2017-02-01

Honeybee colonies (Apis mellifera) serve as attractive hosts for a variety of pathogens providing optimal temperatures, humidity, and an abundance of food. Thus, honeybees have to deal with pathogens throughout their lives and, even as larvae they are affected by severe brood diseases like the European Foulbrood caused by Melissococcus plutonius. Accordingly, it is highly adaptive that larval food jelly contains antibiotic compounds. However, although food jelly is primarily consumed by bee larvae, studies investigating the antibiotic effects of this jelly have largely concentrated on bacterial human diseases. In this study, we show that royal jelly fed to queen larvae and added to the jelly of drone and worker larvae, inhibits not only the growth of European Foulbrood-associated bacteria but also its causative agent M. plutonius. This effect is shown to be caused by the main protein (major royal jelly protein 1) of royal jelly. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Scientists Train Honeybees to Detect Explosives

ScienceCinema

None

2018-01-16

Members of the Los Alamos National Laboratory Stealthy Insect Sensor Project team have been able to harness the honeybee's exceptional olfactory sense by using the bees' natural reaction to nectar, a proboscis extension reflex (sticking out their tongue) to record an unmistakable response to a scent. Using Pavlovian techniques, researchers were able to train the bees to give a positive detection response via the PER when exposed to vapors from TNT, C4, and TATP explosives. The Stealthy Insect Sensor Project was born out of a global threat from the growing use of improvised explosive devices or IEDs, especially those that present a critical vulnerability for American military troops in Iraq and Afghanistan, and as an emerging danger for civilians worldwide. Current strategies to detect explosives are expensive and, in the case of trained detection dogs, too obtrusive to be used very discreetly. With bees however, they are small and discreet, offering the element of surprise. They're also are inexpensive to maintain and even easier to train than dogs. As a result of this need, initial funding for the work was provided by a development grant from the Defense Advanced Research Projects Agency.

Scientists Train Honeybees to Detect Explosives

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2008-03-21

Members of the Los Alamos National Laboratory Stealthy Insect Sensor Project team have been able to harness the honeybee's exceptional olfactory sense by using the bees' natural reaction to nectar, a proboscis extension reflex (sticking out their tongue) to record an unmistakable response to a scent. Using Pavlovian techniques, researchers were able to train the bees to give a positive detection response via the PER when exposed to vapors from TNT, C4, and TATP explosives. The Stealthy Insect Sensor Project was born out of a global threat from the growing use of improvised explosive devices or IEDs, especially those thatmore » present a critical vulnerability for American military troops in Iraq and Afghanistan, and as an emerging danger for civilians worldwide. Current strategies to detect explosives are expensive and, in the case of trained detection dogs, too obtrusive to be used very discreetly. With bees however, they are small and discreet, offering the element of surprise. They're also are inexpensive to maintain and even easier to train than dogs. As a result of this need, initial funding for the work was provided by a development grant from the Defense Advanced Research Projects Agency.« less

Expert explanations of honeybee losses in areas of extensive agriculture in France: Gaucho® compared with other supposed causal factors

NASA Astrophysics Data System (ADS)

Maxim, L.; van der Sluijs, J. P.

2010-01-01

Debates on causality are at the core of controversies as regards environmental changes. The present paper presents a new method for analyzing controversies on causality in a context of social debate and the results of its empirical testing. The case study used is the controversy as regards the role played by the insecticide Gaucho®, compared with other supposed causal factors, in the substantial honeybee (Apis mellifera L.) losses reported to have occurred in France between 1994 and 2004. The method makes use of expert elicitation of the perceived strength of evidence regarding each of Bradford Hill's causality criteria, as regards the link between each of eight possible causal factors identified in attempts to explain each of five signs observed in honeybee colonies. These judgments are elicited from stakeholders and experts involved in the debate, i.e., representatives of Bayer Cropscience, of the Ministry of Agriculture, of the French Food Safety Authority, of beekeepers and of public scientists. We show that the intense controversy observed in confused and passionate public discourses is much less salient when the various arguments are structured using causation criteria. The contradictions between the different expert views have a triple origin: (1) the lack of shared definition and quantification of the signs observed in colonies; (2) the lack of specialist knowledge on honeybees; and (3) the strategic discursive practices associated with the lack of trust between experts representing stakeholders having diverging stakes in the case.

In-depth proteomic analysis of Varroa destructor: Detection of DWV-complex, ABPV, VdMLV and honeybee proteins in the mite.

PubMed

Erban, Tomas; Harant, Karel; Hubalek, Martin; Vitamvas, Pavel; Kamler, Martin; Poltronieri, Palmiro; Tyl, Jan; Markovic, Martin; Titera, Dalibor

2015-09-11

We investigated pathogens in the parasitic honeybee mite Varroa destructor using nanoLC-MS/MS (TripleTOF) and 2D-E-MS/MS proteomics approaches supplemented with affinity-chromatography to concentrate trace target proteins. Peptides were detected from the currently uncharacterized Varroa destructor Macula-like virus (VdMLV), the deformed wing virus (DWV)-complex and the acute bee paralysis virus (ABPV). Peptide alignments revealed detection of complete structural DWV-complex block VP2-VP1-VP3, VDV-1 helicase and single-amino-acid substitution A/K/Q in VP1, the ABPV structural block VP1-VP4-VP2-VP3 including uncleaved VP4/VP2, and VdMLV coat protein. Isoforms of viral structural proteins of highest abundance were localized via 2D-E. The presence of all types of capsid/coat proteins of a particular virus suggested the presence of virions in Varroa. Also, matches between the MWs of viral structural proteins on 2D-E and their theoretical MWs indicated that viruses were not digested. The absence/scarce detection of non-structural proteins compared with high-abundance structural proteins suggest that the viruses did not replicate in the mite; hence, virions accumulate in the Varroa gut via hemolymph feeding. Hemolymph feeding also resulted in the detection of a variety of honeybee proteins. The advantages of MS-based proteomics for pathogen detection, false-positive pathogen detection, virus replication, posttranslational modifications, and the presence of honeybee proteins in Varroa are discussed.

In-depth proteomic analysis of Varroa destructor: Detection of DWV-complex, ABPV, VdMLV and honeybee proteins in the mite

PubMed Central

Erban, Tomas; Harant, Karel; Hubalek, Martin; Vitamvas, Pavel; Kamler, Martin; Poltronieri, Palmiro; Tyl, Jan; Markovic, Martin; Titera, Dalibor

2015-01-01

We investigated pathogens in the parasitic honeybee mite Varroa destructor using nanoLC-MS/MS (TripleTOF) and 2D-E-MS/MS proteomics approaches supplemented with affinity-chromatography to concentrate trace target proteins. Peptides were detected from the currently uncharacterized Varroa destructor Macula-like virus (VdMLV), the deformed wing virus (DWV)-complex and the acute bee paralysis virus (ABPV). Peptide alignments revealed detection of complete structural DWV-complex block VP2-VP1-VP3, VDV-1 helicase and single-amino-acid substitution A/K/Q in VP1, the ABPV structural block VP1-VP4-VP2-VP3 including uncleaved VP4/VP2, and VdMLV coat protein. Isoforms of viral structural proteins of highest abundance were localized via 2D-E. The presence of all types of capsid/coat proteins of a particular virus suggested the presence of virions in Varroa. Also, matches between the MWs of viral structural proteins on 2D-E and their theoretical MWs indicated that viruses were not digested. The absence/scarce detection of non-structural proteins compared with high-abundance structural proteins suggest that the viruses did not replicate in the mite; hence, virions accumulate in the Varroa gut via hemolymph feeding. Hemolymph feeding also resulted in the detection of a variety of honeybee proteins. The advantages of MS-based proteomics for pathogen detection, false-positive pathogen detection, virus replication, posttranslational modifications, and the presence of honeybee proteins in Varroa are discussed. PMID:26358842

BEEHAVE: a systems model of honeybee colony dynamics and foraging to explore multifactorial causes of colony failure

PubMed Central

Becher, Matthias A; Grimm, Volker; Thorbek, Pernille; Horn, Juliane; Kennedy, Peter J; Osborne, Juliet L

2014-01-01

A notable increase in failure of managed European honeybee Apis mellifera L. colonies has been reported in various regions in recent years. Although the underlying causes remain unclear, it is likely that a combination of stressors act together, particularly varroa mites and other pathogens, forage availability and potentially pesticides. It is experimentally challenging to address causality at the colony scale when multiple factors interact. In silico experiments offer a fast and cost-effective way to begin to address these challenges and inform experiments. However, none of the published bee models combine colony dynamics with foraging patterns and varroa dynamics. We have developed a honeybee model, BEEHAVE, which integrates colony dynamics, population dynamics of the varroa mite, epidemiology of varroa-transmitted viruses and allows foragers in an agent-based foraging model to collect food from a representation of a spatially explicit landscape. We describe the model, which is freely available online (www.beehave-model.net). Extensive sensitivity analyses and tests illustrate the model's robustness and realism. Simulation experiments with various combinations of stressors demonstrate, in simplified landscape settings, the model's potential: predicting colony dynamics and potential losses with and without varroa mites under different foraging conditions and under pesticide application. We also show how mitigation measures can be tested. Synthesis and applications. BEEHAVE offers a valuable tool for researchers to design and focus field experiments, for regulators to explore the relative importance of stressors to devise management and policy advice and for beekeepers to understand and predict varroa dynamics and effects of management interventions. We expect that scientists and stakeholders will find a variety of applications for BEEHAVE, stimulating further model development and the possible inclusion of other stressors of potential importance to honeybee

BEEHAVE: a systems model of honeybee colony dynamics and foraging to explore multifactorial causes of colony failure.

PubMed

Becher, Matthias A; Grimm, Volker; Thorbek, Pernille; Horn, Juliane; Kennedy, Peter J; Osborne, Juliet L

2014-04-01

A notable increase in failure of managed European honeybee Apis mellifera L. colonies has been reported in various regions in recent years. Although the underlying causes remain unclear, it is likely that a combination of stressors act together, particularly varroa mites and other pathogens, forage availability and potentially pesticides. It is experimentally challenging to address causality at the colony scale when multiple factors interact. In silico experiments offer a fast and cost-effective way to begin to address these challenges and inform experiments. However, none of the published bee models combine colony dynamics with foraging patterns and varroa dynamics.We have developed a honeybee model, BEEHAVE, which integrates colony dynamics, population dynamics of the varroa mite, epidemiology of varroa-transmitted viruses and allows foragers in an agent-based foraging model to collect food from a representation of a spatially explicit landscape.We describe the model, which is freely available online (www.beehave-model.net). Extensive sensitivity analyses and tests illustrate the model's robustness and realism. Simulation experiments with various combinations of stressors demonstrate, in simplified landscape settings, the model's potential: predicting colony dynamics and potential losses with and without varroa mites under different foraging conditions and under pesticide application. We also show how mitigation measures can be tested. Synthesis and applications . BEEHAVE offers a valuable tool for researchers to design and focus field experiments, for regulators to explore the relative importance of stressors to devise management and policy advice and for beekeepers to understand and predict varroa dynamics and effects of management interventions. We expect that scientists and stakeholders will find a variety of applications for BEEHAVE, stimulating further model development and the possible inclusion of other stressors of potential importance to honeybee colony

Infection of Melissococcus plutonius clonal complex 12 strain in European honeybee larvae is essentially confined to the digestive tract

PubMed Central

TAKAMATSU, Daisuke; SATO, Masumi; YOSHIYAMA, Mikio

2015-01-01

Melissococcus plutonius is an important pathogen that causes European foulbrood (EFB) in honeybee larvae. Recently, we discovered a group of M. plutonius strains that are phenotypically and genetically distinct from other strains. These strains belong to clonal complex (CC) 12, as determined by multilocus sequence typing analysis, and show atypical cultural and biochemical characteristics in vitro compared with strains of other CCs tested. Although EFB is considered to be a purely intestinal infection according to early studies, it is unknown whether the recently found CC12 strains cause EFB by the same pathomechanism. In this study, to obtain a better understanding of EFB, we infected European honeybee (Apis mellifera) larvae per os with a well-characterized CC12 strain, DAT561, and analyzed the larvae histopathologically. Ingested DAT561 was mainly localized in the midgut lumen surrounded by the peritrophic matrix (PM) in the larvae. In badly affected larvae, the PM and midgut epithelial cells degenerated, and some bacterial cells were detected outside of the midgut. However, they did not proliferate in the deep tissues actively. By immunohistochemical analysis, the PM was stained with anti-M. plutonius serum in most of the DAT561-infected larvae. In some larvae, luminal surfaces of the PM were more strongly stained than the inside. These results suggest that infection of CC12 strain in honeybee larvae is essentially confined to the intestine. Moreover, our results imply the presence of M. plutonius-derived substances diffusing into the larval tissues in the course of infection. PMID:26256232

Two odometers in honeybees?

PubMed

Dacke, M; Srinivasan, M V

2008-10-01

Although several studies have examined how honeybees gauge and report the distance and direction of a food source to their nestmates, relatively little is known about how this information is combined to obtain a representation of the position of the food source. In this study we manipulate the amount of celestial compass information available to the bee during flight, and analyse the encoding of spatial information in the waggle dance as well as in the navigation of the foraging bee. We find that the waggle dance encodes information about the total distance flown to the food source, even when celestial compass cues are available only for a part of the journey. This stands in contrast to how a bee gauges distance flown when it navigates back to a food source that it already knows. When bees were trained to find a feeder placed at a fixed distance in a tunnel in which celestial cues were partially occluded and then tested in a tunnel that was fully open to the sky, they searched for the feeder at a distance that corresponds closely to the distance that was flown under the open sky during the training. Thus, when navigating back to a food source, information about distance travelled is disregarded when there is no concurrent input from the celestial compass. We suggest that bees may possess two different odometers - a 'community' odometer that is used to provide information to nestmates via the dance, and a 'personal' odometer that is used by an experienced individual to return to a previously visited source.

Honey loading for pollen collection: regulation of crop content in honeybee pollen foragers on leaving hive

NASA Astrophysics Data System (ADS)

Harano, Ken-ichi; Mitsuhata-Asai, Akiko; Sasaki, Masami

2014-07-01

Before foraging honeybees leave the hive, each bee loads its crop with some amount of honey "fuel" depending on the distance to the food source and foraging experience. For pollen collection, there is evidence that foragers carry additional honey as "glue" to build pollen loads. This study examines whether pollen foragers of the European honeybee Apis mellifera regulate the size of the crop load according to food-source distances upon leaving the hive and how foraging experience affects load regulation. The crop contents of bees foraging on crape myrtle Lagerstroemia indica, which has no nectary, were larger than those foraging on nectar from other sources, confirming a previous finding that pollen foragers carry glue in addition to fuel honey from the hive. Crop contents of both waggle dancers and dance followers showed a significant positive correlation with waggle-run durations. These results suggest that bees carry a distance-dependent amount of fuel honey in addition to a fixed amount of glue honey. Crop contents on leaving the hive were statistically larger in dancers than followers. Based on these results, we suggest that pollen foragers use information obtained through foraging experience to adjust crop contents on leaving the hive.

Honey loading for pollen collection: regulation of crop content in honeybee pollen foragers on leaving hive.

PubMed

Harano, Ken-ichi; Mitsuhata-Asai, Akiko; Sasaki, Masami

2014-07-01

Before foraging honeybees leave the hive, each bee loads its crop with some amount of honey "fuel" depending on the distance to the food source and foraging experience. For pollen collection, there is evidence that foragers carry additional honey as "glue" to build pollen loads. This study examines whether pollen foragers of the European honeybee Apis mellifera regulate the size of the crop load according to food-source distances upon leaving the hive and how foraging experience affects load regulation. The crop contents of bees foraging on crape myrtle Lagerstroemia indica, which has no nectary, were larger than those foraging on nectar from other sources, confirming a previous finding that pollen foragers carry glue in addition to fuel honey from the hive. Crop contents of both waggle dancers and dance followers showed a significant positive correlation with waggle-run durations. These results suggest that bees carry a distance-dependent amount of fuel honey in addition to a fixed amount of glue honey. Crop contents on leaving the hive were statistically larger in dancers than followers. Based on these results, we suggest that pollen foragers use information obtained through foraging experience to adjust crop contents on leaving the hive.

Honeybees (Apis mellifera) learn to discriminate the smell of organic compounds from their respective deuterated isotopomers

PubMed Central

Gronenberg, Wulfila; Raikhelkar, Ajay; Abshire, Eric; Stevens, Jennifer; Epstein, Eric; Loyola, Karin; Rauscher, Michael; Buchmann, Stephen

2014-01-01

The understanding of physiological and molecular processes underlying the sense of smell has made considerable progress during the past three decades, revealing the cascade of molecular steps that lead to the activation of olfactory receptor (OR) neurons. However, the mode of primary interaction of odorant molecules with the OR proteins within the sensory cells is still enigmatic. Two different concepts try to explain these interactions: the ‘odotope hypothesis’ suggests that OR proteins recognize structural aspects of the odorant molecule, whereas the ‘vibration hypothesis’ proposes that intra-molecular vibrations are the basis for the recognition of the odorant by the receptor protein. The vibration hypothesis predicts that OR proteins should be able to discriminate compounds containing deuterium from their common counterparts which contain hydrogen instead of deuterium. This study tests this prediction in honeybees (Apis mellifera) using the proboscis extension reflex learning in a differential conditioning paradigm. Rewarding one odour (e.g. a deuterated compound) with sucrose and not rewarding the respective analogue (e.g. hydrogen-based odorant) shows that honeybees readily learn to discriminate hydrogen-based odorants from their deuterated counterparts and supports the idea that intra-molecular vibrations may contribute to odour discrimination. PMID:24452031

Multi-residue method for the determination of pesticides and pesticide metabolites in honeybees by liquid and gas chromatography coupled with tandem mass spectrometry--Honeybee poisoning incidents.

PubMed

Kiljanek, Tomasz; Niewiadowska, Alicja; Semeniuk, Stanisław; Gaweł, Marta; Borzęcka, Milena; Posyniak, Andrzej

2016-02-26

A method for the determination of 200 pesticides and pesticide metabolites in honeybee samples has been developed and validated. Almost 98% of compounds included in this method are approved to use within European Union, as active substances of plant protection products or veterinary medicinal products used by beekeepers to control mites Varroa destructor in hives. Many significant metabolites, like metabolites of imidacloprid, thiacloprid, fipronil, methiocarb and amitraz, are also possible to detect. The sample preparation was based on the buffered QuEChERS method. Samples of bees were extracted with acetonitrile containing 1% acetic acid and then subjected to clean-up by dispersive solid phase extraction (dSPE) using a new Z-Sep+ sorbent and PSA. The majority of pesticides, including neonicotionoids and their metabolites, were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) but some of pesticides, especially pyrethroid insecticides, were analyzed by gas chromatography tandem mass spectrometry (GC-MS/MS). The procedure was validated according to the Guidance document SANCO/12571/2013 at four concentration levels: 1, 5, 10 and 100 ng/g bees and verified in the international proficiency test. The analysis of bee samples spiked at the limit of quantification (LOQ) showed about 98% mean recovery value (trueness) and 97% of analytes showed recovery in the required range of 70-120% and RSDr (precision) below 20%. Linearity and matrix effects were also established. The LOQs of pesticides were in the range of 1-100 ng/g. The developed method allows determination of insecticides at concentrations of 10 ng/g or less, except abamectin and tebufenozide. LOQ values are lower than the median lethal doses LD50 for bees. The method was used to investigate more than 70 honeybee poisoning incidents. Data about detected pesticides and their metabolites are included. Copyright © 2016 Elsevier B.V. All rights reserved.

Scouts behave as streakers in honeybee swarms

NASA Astrophysics Data System (ADS)

Greggers, Uwe; Schöning, Caspar; Degen, Jacqueline; Menzel, Randolf

2013-08-01

Harmonic radar tracking was used to record the flights of scout bees during takeoff and initial flight path of two honeybee swarms. One swarm remained intact and performed a full flight to a destination beyond the range of the harmonic radar, while a second swarm disintegrated within the range of the radar and most of the bees returned to the queen. The initial stretch of the full flight is characterized by accelerating speed, whereas the disintegrating swarm flew steadily at low speed. The two scouts in the swarm displaying full flight performed characteristic flight maneuvers. They flew at high speed when traveling in the direction of their destination and slowed down or returned over short stretches at low speed. Scouts in the disintegrating swarm did not exhibit the same kind of characteristic flight performance. Our data support the streaker bee hypothesis proposing that scout bees guide the swarm by traveling at high speed in the direction of the new nest site for short stretches of flight and slowing down when reversing flight direction.

Regional Distribution Models with Lack of Proximate Predictors: Africanized Honeybees Expanding North

NASA Technical Reports Server (NTRS)

Jarnevich, Catherine S.; Esaias, Wayne E.; Ma, Peter L. A.; Morisette, Jeffery T.; Nickeson, Jaime E.; Stohlgren, Thomas J.; Holcombe, Tracy R.; Nightingale, Joanne M.; Wolfe, Robert E.; Tan, Bin

2014-01-01

Species distribution models have often been hampered by poor local species data, reliance on coarse-scale climate predictors and the assumption that species-environment relationships, even with non-proximate predictors, are consistent across geographical space. Yet locally accurate maps of invasive species, such as the Africanized honeybee (AHB) in North America, are needed to support conservation efforts. Current AHB range maps are relatively coarse and are inconsistent with observed data. Our aim was to improve distribution maps using more proximate predictors (phenology) and using regional models rather than one across the entire range of interest to explore potential differences in drivers.

Regional distribution models with lack of proximate predictors: Africanized honeybees expanding north

USGS Publications Warehouse

Jarnevich, Catherine S.; Esaias, Wayne E.; Ma, Peter L.A.; Morisette, Jeffery T.; Nickeson, Jaime E.; Stohlgren, Thomas J.; Holcombe, Tracy R.; Nightingale, Joanne M.; Wolfe, Robert E.; Tan, Bin

2014-01-01

Species distribution models have often been hampered by poor local species data, reliance on coarse-scale climate predictors and the assumption that species–environment relationships, even with non-proximate predictors, are consistent across geographical space. Yet locally accurate maps of invasive species, such as the Africanized honeybee (AHB) in North America, are needed to support conservation efforts. Current AHB range maps are relatively coarse and are inconsistent with observed data. Our aim was to improve distribution maps using more proximate predictors (phenology) and using regional models rather than one across the entire range of interest to explore potential differences in drivers.

Assessment of heavy metal pollution in Córdoba (Spain) by biomonitoring foraging honeybee.

PubMed

Gutiérrez, Miriam; Molero, Rafael; Gaju, Miquel; van der Steen, Josef; Porrini, Claudio; Ruiz, José Antonio

2015-10-01

Due to features that make them outstanding environmental bioindicator, colonies of Apis mellifera are being used to study environmental pollution. The primary objective of this research was to use honeybee colonies to identify heavy metals and determine their utility for environmental management. Five stations each with two A. mellifera hives were strategically located in urban, industrial, agricultural and forested areas within the municipality of Córdoba (Spain), and foraging bees were collected from April to December in 2007, 2009 and 2010 to analyse spatial and temporal variation in Pb, Cr, Ni and Cd pollution. Metal concentrations, in milligram per kilogram of honeybee, were determined by inductively coupled plasma-atomic emission spectrometry and graphite furnace atomic absorption spectrophotometry. Significant differences in concentrations were found among the various locations and periods. The highest number of values exceeding the upper reference thresholds proposed for this study (Pb, 0.7 mg/kg; Cr, 0.12 mg/kg; Ni, 0.3 mg/kg; and Cd, 0.1 mg/kg) was observed for Pb and Cr (6.25% respectively), station S4 (13.22%), year 2007 (20.83%) and in months of May and July (11.90% each). Regarding the Cd, which was analysed only in 2010, the highest number of values exceeding the upper reference thresholds was 40%. Biomonitoring with colonies of A. mellifera could contribute to improved surveillance and control systems for atmospheric pollution by integrating qualitative and quantitative assessments, thus facilitating prevention and readiness in the event of environmental crises.

Side-Specificity of Olfactory Learning in the Honeybee: Generalization between Odors and Sides

PubMed Central

Sandoz, Jean-Christophe; Menzel, Randolf

2001-01-01

Honeybees (Apis mellifera) can be trained to associate an odor stimulus with a sucrose reward. The neural structures involved in the detection and integration of olfactory stimuli are represented bilaterally in the brain. Little is known about the respective roles of the two sides of the brain in olfactory learning. Does each side learn independently of the other, or do they communicate, and if so, to what extent and at what level of neural integration? We addressed these questions using the proboscis extension response (PER) conditioning paradigm applied in a preparation that allows the separation of the two input sides during olfactory stimulations. Bees conditioned to two odorants A and B, one being learned on each side (A+/B+ training), showed in extinction tests rather unspecific responses: They responded to both odorants on both sides. This could be attributable to either a transfer of the learned information between sides, or to a generalization between odorants on each side. By subjecting bees to conditioning on one side only (A+/0 training), we found that the learned information is indeed transferred between sides. However, when bees were trained explicitly to give opposite values to the two odorants on the two sides (A+B−/B+A− training), they showed clear side-specific response patterns to these odorants. These results are used in the elaboration of a functional model of laterality of olfactory learning and memory processing in the honeybee brain. PMID:11584076

Bee-hawking by the wasp, Vespa velutina, on the honeybees Apis cerana and A. mellifera.

PubMed

Tan, K; Radloff, S E; Li, J J; Hepburn, H R; Yang, M X; Zhang, L J; Neumann, P

2007-06-01

The vespine wasps, Vespa velutina, specialise in hawking honeybee foragers returning to their nests. We studied their behaviour in China using native Apis cerana and introduced A. mellifera colonies. When the wasps are hawking, A. cerana recruits threefold more guard bees to stave off predation than A. mellifera. The former also utilises wing shimmering as a visual pattern disruption mechanism, which is not shown by A. mellifera. A. cerana foragers halve the time of normal flight needed to dart into the nest entrance, while A. mellifera actually slows down in sashaying flight manoeuvres. V. velutina preferentially hawks A. mellifera foragers when both A. mellifera and A. cerana occur in the same apiary. The pace of wasp-hawking was highest in mid-summer but the frequency of hawking wasps was three times higher at A. mellifera colonies than at the A. cerana colonies. The wasps were taking A. mellifera foragers at a frequency eightfold greater than A. cerana foragers. The final hawking success rates of the wasps were about three times higher for A. mellifera foragers than for A. cerana. The relative success of native A. cerana over European A. mellifera in thwarting predation by the wasp V. velutina is interpreted as the result of co-evolution between the Asian wasp and honeybee, respectively.

The invasive Korea and Japan types of Varroa destructor, ectoparasitic mites of the Western honeybee (Apis mellifera), are two partly isolated clones

PubMed Central

Solignac, Michel; Cornuet, Jean-Marie; Vautrin, Dominique; Le Conte, Yves; Anderson, Denis; Evans, Jay; Cros-Arteil, Sandrine; Navajas, Maria

2005-01-01

Varroa destructor, now a major pest of the Western honeybee, Apis mellifera, switched from its original host, the Eastern honeybee, A. cerana, ca. 50 years ago. So far, only two out of several known mitochondrial haplotypes of V. destructor have been found to be capable of reproducing on A. mellifera (Korea and Japan). These haplotypes are associated in almost complete cytonuclear disequilibrium to diagnostic alleles at 11 microsatellite loci. By contrast, microsatellite polymorphism within each type is virtually absent, because of a severe bottleneck at the time of host change. Accordingly, 12 mitochondrial sequences of 5185 nucleotides displayed 0.40% of nucleotide divergence between haplotypes and no intra haplotype variation. Hence, each type has a quasi-clonal structure. The nascent intratype variability is subsequent to the clone formation 50 years ago: in both types the variant alleles differ from the most common by one (in 10 cases), two (five cases) or three (one case) repeated motifs. In addition to individuals of the two ‘pure’ types, five F1 hybrids and 19 recombinant individuals (Japan alleles introgressed into the Korea genetic background) were detected. The existence of F1 and recombinant individuals in admixed populations requires that double infestations of honeybee cells occur in a high proportion but the persistence of pure types suggests a post-zygotic isolation between the two clones. PMID:15734696

Conditioning procedure and color discrimination in the honeybee Apis mellifera

NASA Astrophysics Data System (ADS)

Giurfa, Martin

We studied the influence of the conditioning procedure on color discrimination by free-flying honeybees. We asked whether absolute and differential conditioning result in different discrimination capabilities for the same pairs of colored targets. In absolute conditioning, bees were rewarded on a single color; in differential conditioning, bees were rewarded on the same color but an alternative, non-rewarding, similar color was also visible. In both conditioning procedures, bees learned their respective task and could also discriminate the training stimulus from a novel stimulus that was perceptually different from the trained one. Discrimination between perceptually closer stimuli was possible after differential conditioning but not after absolute conditioning. Differences in attention inculcated by these training procedures may underlie the different discrimination performances of the bees.

The Influence of Gustatory and Olfactory Experiences on Responsiveness to Reward in the Honeybee

PubMed Central

Ramírez, Gabriela P.; Martínez, Andrés S.; Fernández, Vanesa M.; Corti Bielsa, Gonzalo; Farina, Walter M.

2010-01-01

Background Honeybees (Apis mellifera) exhibit an extraordinarily tuned division of labor that depends on age polyethism. This adjustment is generally associated with the fact that individuals of different ages display different response thresholds to given stimuli, which determine specific behaviors. For instance, the sucrose-response threshold (SRT) which largely depends on genetic factors may also be affected by the nectar sugar content. However, it remains unknown whether SRTs in workers of different ages and tasks can differ depending on gustatory and olfactory experiences. Methodology Groups of worker bees reared either in an artificial environment or else in a queen-right colony, were exposed to different reward conditions at different adult ages. Gustatory response scores (GRSs) and odor-memory retrieval were measured in bees that were previously exposed to changes in food characteristics. Principal Findings Results show that the gustatory responses of pre-foraging-aged bees are affected by changes in sucrose solution concentration and also to the presence of an odor provided it is presented as scented sucrose solution. In contrast no differences in worker responses were observed when presented with odor only in the rearing environment. Fast modulation of GRSs was observed in older bees (12–16 days of age) which are commonly involved in food processing tasks within the hive, while slower modulation times were observed in younger bees (commonly nurse bees, 6–9 days of age). This suggests that older food-processing bees have a higher plasticity when responding to fluctuations in resource information than younger hive bees. Adjustments in the number of trophallaxis events were also found when scented food circulated inside the nest, and this was positively correlated with the differences in timing observed in gustatory responsiveness and memory retention for hive bees of different age classes. Conclusions This work demonstrates the accessibility of

In situ hybridization analysis of the expression of futsch, tau, and MESK2 homologues in the brain of the European honeybee (Apis mellifera L.).

PubMed

Kaneko, Kumi; Hori, Sayaka; Morimoto, Mai M; Nakaoka, Takayoshi; Paul, Rajib Kumar; Fujiyuki, Tomoko; Shirai, Kenichi; Wakamoto, Akiko; Tsuboko, Satomi; Takeuchi, Hideaki; Kubo, Takeo

2010-02-16

The importance of visual sense in Hymenopteran social behavior is suggested by the existence of a Hymenopteran insect-specific neural circuit related to visual processing and the fact that worker honeybee brain changes morphologically according to its foraging experience. To analyze molecular and neural bases that underlie the visual abilities of the honeybees, we used a cDNA microarray to search for gene(s) expressed in a neural cell-type preferential manner in a visual center of the honeybee brain, the optic lobes (OLs). Expression analysis of candidate genes using in situ hybridization revealed two genes expressed in a neural cell-type preferential manner in the OLs. One is a homologue of Drosophila futsch, which encodes a microtubule-associated protein and is preferentially expressed in the monopolar cells in the lamina of the OLs. The gene for another microtubule-associated protein, tau, which functionally overlaps with futsch, was also preferentially expressed in the monopolar cells, strongly suggesting the functional importance of these two microtubule-associated proteins in monopolar cells. The other gene encoded a homologue of Misexpression Suppressor of Dominant-negative Kinase Suppressor of Ras 2 (MESK2), which might activate Ras/MAPK-signaling in Drosophila. MESK2 was expressed preferentially in a subclass of neurons located in the ventral region between the lamina and medulla neuropil in the OLs, suggesting that this subclass is a novel OL neuron type characterized by MESK2-expression. These three genes exhibited similar expression patterns in the worker, drone, and queen brains, suggesting that they function similarly irrespective of the honeybee sex or caste. Here we identified genes that are expressed in a monopolar cell (Amfutsch and Amtau) or ventral medulla-preferential manner (AmMESK2) in insect OLs. These genes may aid in visualizing neurites of monopolar cells and ventral medulla cells, as well as in analyzing the function of these neurons.

Effects of high voltage transmission lines on honeybees: a feasibility study. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenberg, B.

1977-07-01

Methodology is described for the investigation of the effects of electric fields generated by high-tension power lines on honeybees (Apis mellifera L.). The parameters to be measured include colony population, honey stores, amount of acoustical noise generated by the bees, in-hive temperature, incidence of queen cell production, and tendency to swarm. Accompanying dosimetric support includes in-hive electric field measurements, development of shielding to eliminate the electric field from selected colonies, analysis of the acoustical data, and periodic checks on the ambient electric field present under the line and at the control site.

Honeybees (Apis mellifera) Learn Color Discriminations via Differential Conditioning Independent of Long Wavelength (Green) Photoreceptor Modulation

PubMed Central

Wijesekara Witharanage, Randika; Rosa, Marcello G. P.

2012-01-01

Background Recent studies on colour discrimination suggest that experience is an important factor in how a visual system processes spectral signals. In insects it has been shown that differential conditioning is important for processing fine colour discriminations. However, the visual system of many insects, including the honeybee, has a complex set of neural pathways, in which input from the long wavelength sensitive (‘green’) photoreceptor may be processed either as an independent achromatic signal or as part of a trichromatic opponent-colour system. Thus, a potential confound of colour learning in insects is the possibility that modulation of the ‘green’ photoreceptor could underlie observations. Methodology/Principal Findings We tested honeybee vision using light emitting diodes centered on 414 and 424 nm wavelengths, which limit activation to the short-wavelength-sensitive (‘UV’) and medium-wavelength-sensitive (‘blue’) photoreceptors. The absolute irradiance spectra of stimuli was measured and modelled at both receptor and colour processing levels, and stimuli were then presented to the bees in a Y-maze at a large visual angle (26°), to ensure chromatic processing. Sixteen bees were trained over 50 trials, using either appetitive differential conditioning (N = 8), or aversive-appetitive differential conditioning (N = 8). In both cases the bees slowly learned to discriminate between the target and distractor with significantly better accuracy than would be expected by chance. Control experiments confirmed that changing stimulus intensity in transfers tests does not significantly affect bee performance, and it was possible to replicate previous findings that bees do not learn similar colour stimuli with absolute conditioning. Conclusion Our data indicate that honeybee colour vision can be tuned to relatively small spectral differences, independent of ‘green’ photoreceptor contrast and brightness cues. We thus show that colour vision

Honeybee society destruction by losing control of self-reproduction

NASA Astrophysics Data System (ADS)

Zhang, Peipei; Su, Beibei; He, Da-Ren

2004-03-01

Recently the mechanism of the damage caused by invasion of Apis mellifera capensis honeybee into the normal A. M. Scutellata colonies became interesting for scientists due to the fact that the mechanism may resemble those of cancer vicious hyperplasia, spreading of some epidemic, and turbulence of society induced by some bad society groups. For the mechanism, we suggest a new guess, which means that the losing control of self-reproduction disturbs and throws information structure of the society into confuse. We also simulate the damage process with a cellular automata based on the idea. The simulation shows that the process is equivalent to a non-equilibrium percolation phase transition. This discussion remind us that the management and monitor on the information network between society members may be a more effective way for avoiding the overflow of the destructor sub-colonies.

Parallel representation of stimulus identity and intensity in a dual pathway model inspired by the olfactory system of the honeybee.

PubMed

Schmuker, Michael; Yamagata, Nobuhiro; Nawrot, Martin Paul; Menzel, Randolf

2011-01-01

The honeybee Apis mellifera has a remarkable ability to detect and locate food sources during foraging, and to associate odor cues with food rewards. In the honeybee's olfactory system, sensory input is first processed in the antennal lobe (AL) network. Uniglomerular projection neurons (PNs) convey the sensory code from the AL to higher brain regions via two parallel but anatomically distinct pathways, the lateral and the medial antenno-cerebral tract (l- and m-ACT). Neurons innervating either tract show characteristic differences in odor selectivity, concentration dependence, and representation of mixtures. It is still unknown how this differential stimulus representation is achieved within the AL network. In this contribution, we use a computational network model to demonstrate that the experimentally observed features of odor coding in PNs can be reproduced by varying lateral inhibition and gain control in an otherwise unchanged AL network. We show that odor coding in the l-ACT supports detection and accurate identification of weak odor traces at the expense of concentration sensitivity, while odor coding in the m-ACT provides the basis for the computation and following of concentration gradients but provides weaker discrimination power. Both coding strategies are mutually exclusive, which creates a tradeoff between detection accuracy and sensitivity. The development of two parallel systems may thus reflect an evolutionary solution to this problem that enables honeybees to achieve both tasks during bee foraging in their natural environment, and which could inspire the development of artificial chemosensory devices for odor-guided navigation in robots.

Mixing of Honeybees with Different Genotypes Affects Individual Worker Behavior and Transcription of Genes in the Neuronal Substrate

PubMed Central

Bienefeld, Kaspar; Beye, Martin

2012-01-01

Division of labor in social insects has made the evolution of collective traits possible that cannot be achieved by individuals alone. Differences in behavioral responses produce variation in engagement in behavioral tasks, which as a consequence, generates a division of labor. We still have little understanding of the genetic components influencing these behaviors, although several candidate genomic regions and genes influencing individual behavior have been identified. Here, we report that mixing of worker honeybees with different genotypes influences the expression of individual worker behaviors and the transcription of genes in the neuronal substrate. These indirect genetic effects arise in a colony because numerous interactions between workers produce interacting phenotypes and genotypes across organisms. We studied hygienic behavior of honeybee workers, which involves the cleaning of diseased brood cells in the colony. We mixed ∼500 newly emerged honeybee workers with genotypes of preferred Low (L) and High (H) hygienic behaviors. The L/H genotypic mixing affected the behavioral engagement of L worker bees in a hygienic task, the cooperation among workers in uncapping single brood cells, and switching between hygienic tasks. We found no evidence that recruiting and task-related stimuli are the primary source of the indirect genetic effects on behavior. We suggested that behavioral responsiveness of L bees was affected by genotypic mixing and found evidence for changes in the brain in terms of 943 differently expressed genes. The functional categories of cell adhesion, cellular component organization, anatomical structure development, protein localization, developmental growth and cell morphogenesis were overrepresented in this set of 943 genes, suggesting that indirect genetic effects can play a role in modulating and modifying the neuronal substrate. Our results suggest that genotypes of social partners affect the behavioral responsiveness and the neuronal

Transcriptome profiling of the honeybee parasite Varroa destructor provides new biological insights into the mite adult life cycle.

PubMed

Mondet, Fanny; Rau, Andrea; Klopp, Christophe; Rohmer, Marine; Severac, Dany; Le Conte, Yves; Alaux, Cedric

2018-05-04

The parasite Varroa destructor represents a significant threat to honeybee colonies. Indeed, development of Varroa infestation within colonies, if left untreated, often leads to the death of the colony. Although its impact on bees has been extensively studied, less is known about its biology and the functional processes governing its adult life cycle and adaptation to its host. We therefore developed a full life cycle transcriptomic catalogue in adult Varroa females and included pairwise comparisons with males, artificially-reared and non-reproducing females (10 life cycle stages and conditions in total). Extensive remodeling of the Varroa transcriptome was observed, with an upregulation of energetic and chitin metabolic processes during the initial and final phases of the life cycle (e.g. phoretic and post-oviposition stages), whereas during reproductive stages in brood cells genes showing functions related to transcriptional regulation were overexpressed. Several neurotransmitter and neuropeptide receptors involved in behavioural regulation, as well as active compounds of salivary glands, were also expressed at a higher level outside the reproductive stages. No difference was detected between artificially-reared phoretic females and their counterparts in colonies, or between females who failed to reproduce and females who successfully reproduced, indicating that phoretic individuals can be reared outside host colonies without impacting their physiology and that mechanisms underlying reproductive failure occur before oogenesis. We discuss how these new findings reveal the remarkable adaptation of Varroa to its host biology and notably to the switch from living on adults to reproducing in sealed brood cells. By spanning the entire adult life cycle, our work captures the dynamic changes in the parasite gene expression and serves as a unique resource for deciphering Varroa biology and identifying new targets for mite control.

Honeybees consolidate navigation memory during sleep.

PubMed

Beyaert, Lisa; Greggers, Uwe; Menzel, Randolf

2012-11-15

Sleep is known to support memory consolidation in animals, including humans. Here we ask whether consolidation of novel navigation memory in honeybees depends on sleep. Foragers were exposed to a forced navigation task in which they learned to home more efficiently from an unexpected release site by acquiring navigational memory during the successful homing flight. This task was quantified using harmonic radar tracking and applied to bees that were equipped with a radio frequency identification device (RFID). The RFID was used to record their outbound and inbound flights and continuously monitor their behavior inside the colony, including their rest during the day and sleep at night. Bees marked with the RFID behaved normally inside and outside the hive. Bees slept longer during the night following forced navigation tasks, but foraging flights of different lengths did not lead to different rest times during the day or total sleep time during the night. Sleep deprivation before the forced navigation task did not alter learning and memory acquired during the task. However, sleep deprivation during the night after forced navigation learning reduced the probability of returning successfully to the hive from the same release site. It is concluded that consolidation of novel navigation memory is facilitated by night sleep in bees.

Social waves in giant honeybees (Apis dorsata) elicit nest vibrations.

PubMed

Kastberger, Gerald; Weihmann, Frank; Hoetzl, Thomas

2013-07-01

Giant honeybees (Apis dorsata) nest in the open and have developed a wide array of strategies for colony defence, including the Mexican wave-like shimmering behaviour. In this collective response, the colony members perform upward flipping of their abdomens in coordinated cascades across the nest surface. The time-space properties of these emergent waves are response patterns which have become of adaptive significance for repelling enemies in the visual domain. We report for the first time that the mechanical impulse patterns provoked by these social waves and measured by laser Doppler vibrometry generate vibrations at the central comb of the nest at the basic (='natural') frequency of 2.156 ± 0.042 Hz which is more than double the average repetition rate of the driving shimmering waves. Analysis of the Fourier spectra of the comb vibrations under quiescence and arousal conditions provoked by mass flight activity and shimmering waves gives rise to the proposal of two possible models for the compound physical system of the bee nest: According to the elastic oscillatory plate model, the comb vibrations deliver supra-threshold cues preferentially to those colony members positioned close to the comb. The mechanical pendulum model predicts that the comb vibrations are sensed by the members of the bee curtain in general, enabling mechanoreceptive signalling across the nest, also through the comb itself. The findings show that weak and stochastic forces, such as general quiescence or diffuse mass flight activity, cause a harmonic frequency spectrum of the comb, driving the comb as an elastic plate. However, shimmering waves provide sufficiently strong forces to move the nest as a mechanical pendulum. This vibratory behaviour may support the colony-intrinsic information hypothesis herein that the mechanical vibrations of the comb provoked by shimmering do have the potential to facilitate immediate communication of the momentary defensive state of the honeybee nest to

Social waves in giant honeybees ( Apis dorsata) elicit nest vibrations

NASA Astrophysics Data System (ADS)

Kastberger, Gerald; Weihmann, Frank; Hoetzl, Thomas

2013-07-01

Giant honeybees ( Apis dorsata) nest in the open and have developed a wide array of strategies for colony defence, including the Mexican wave-like shimmering behaviour. In this collective response, the colony members perform upward flipping of their abdomens in coordinated cascades across the nest surface. The time-space properties of these emergent waves are response patterns which have become of adaptive significance for repelling enemies in the visual domain. We report for the first time that the mechanical impulse patterns provoked by these social waves and measured by laser Doppler vibrometry generate vibrations at the central comb of the nest at the basic (=`natural') frequency of 2.156 ± 0.042 Hz which is more than double the average repetition rate of the driving shimmering waves. Analysis of the Fourier spectra of the comb vibrations under quiescence and arousal conditions provoked by mass flight activity and shimmering waves gives rise to the proposal of two possible models for the compound physical system of the bee nest: According to the elastic oscillatory plate model, the comb vibrations deliver supra-threshold cues preferentially to those colony members positioned close to the comb. The mechanical pendulum model predicts that the comb vibrations are sensed by the members of the bee curtain in general, enabling mechanoreceptive signalling across the nest, also through the comb itself. The findings show that weak and stochastic forces, such as general quiescence or diffuse mass flight activity, cause a harmonic frequency spectrum of the comb, driving the comb as an elastic plate. However, shimmering waves provide sufficiently strong forces to move the nest as a mechanical pendulum. This vibratory behaviour may support the colony-intrinsic information hypothesis herein that the mechanical vibrations of the comb provoked by shimmering do have the potential to facilitate immediate communication of the momentary defensive state of the honeybee nest to the

Honeybee drones are attracted by groups of consexuals in a walking simulator.

PubMed

Brandstaetter, Andreas Simon; Bastin, Florian; Sandoz, Jean-Christophe

2014-04-15

During the mating season, honeybee males, the drones, gather in congregation areas 10-40 m above ground. When a receptive female, a queen, enters the congregation, drones are attracted to her by queen-produced pheromones and visual cues and attempt to mate with the queen in mid-air. It is still unclear how drones and queens find the congregations. Visual cues on the horizon are most probably used for long-range orientation. For shorter-range orientation, however, attraction by a drone-produced aggregation pheromone has been proposed, yet so far its existence has not been confirmed conclusively. The low accessibility of congregation areas high up in the air is a major hurdle and precise control of experimental conditions often remains unsatisfactory in field studies. Here, we used a locomotion compensator-based walking simulator to investigate drones' innate odor preferences under controlled laboratory conditions. We tested behavioral responses of drones to 9-oxo-2-decenoic acid (9-ODA), the major queen-produced sexual attractant, and to queen mandibular pheromone (QMP), an artificial blend of 9-ODA and several other queen-derived components. While 9-ODA strongly dominates the odor bouquet of virgin queens, QMP rather resembles the bouquet of mated queens. In our assay, drones were attracted by 9-ODA, but not by QMP. We also investigated the potential attractiveness of male-derived odors by testing drones' orientation responses to the odor bouquet of groups of 10 living drones or workers. Our results demonstrate that honeybee drones are attracted by groups of other drones (but not by workers), which may indicate a role of drone-emitted cues for the formation of congregations.

Exposure to multiple cholinergic pesticides impairs olfactory learning and memory in honeybees.

PubMed

Williamson, Sally M; Wright, Geraldine A

2013-05-15

Pesticides are important agricultural tools often used in combination to avoid resistance in target pest species, but there is growing concern that their widespread use contributes to the decline of pollinator populations. Pollinators perform sophisticated behaviours while foraging that require them to learn and remember floral traits associated with food, but we know relatively little about the way that combined exposure to multiple pesticides affects neural function and behaviour. The experiments reported here show that prolonged exposure to field-realistic concentrations of the neonicotinoid imidacloprid and the organophosphate acetylcholinesterase inhibitor coumaphos and their combination impairs olfactory learning and memory formation in the honeybee. Using a method for classical conditioning of proboscis extension, honeybees were trained in either a massed or spaced conditioning protocol to examine how these pesticides affected performance during learning and short- and long-term memory tasks. We found that bees exposed to imidacloprid, coumaphos, or a combination of these compounds, were less likely to express conditioned proboscis extension towards an odor associated with reward. Bees exposed to imidacloprid were less likely to form a long-term memory, whereas bees exposed to coumaphos were only less likely to respond during the short-term memory test after massed conditioning. Imidacloprid, coumaphos and a combination of the two compounds impaired the bees' ability to differentiate the conditioned odour from a novel odour during the memory test. Our results demonstrate that exposure to sublethal doses of combined cholinergic pesticides significantly impairs important behaviours involved in foraging, implying that pollinator population decline could be the result of a failure of neural function of bees exposed to pesticides in agricultural landscapes.

Exposure to multiple cholinergic pesticides impairs olfactory learning and memory in honeybees

PubMed Central

Williamson, Sally M.; Wright, Geraldine A.

2013-01-01

SUMMARY Pesticides are important agricultural tools often used in combination to avoid resistance in target pest species, but there is growing concern that their widespread use contributes to the decline of pollinator populations. Pollinators perform sophisticated behaviours while foraging that require them to learn and remember floral traits associated with food, but we know relatively little about the way that combined exposure to multiple pesticides affects neural function and behaviour. The experiments reported here show that prolonged exposure to field-realistic concentrations of the neonicotinoid imidacloprid and the organophosphate acetylcholinesterase inhibitor coumaphos and their combination impairs olfactory learning and memory formation in the honeybee. Using a method for classical conditioning of proboscis extension, honeybees were trained in either a massed or spaced conditioning protocol to examine how these pesticides affected performance during learning and short- and long-term memory tasks. We found that bees exposed to imidacloprid, coumaphos, or a combination of these compounds, were less likely to express conditioned proboscis extension towards an odor associated with reward. Bees exposed to imidacloprid were less likely to form a long-term memory, whereas bees exposed to coumaphos were only less likely to respond during the short-term memory test after massed conditioning. Imidacloprid, coumaphos and a combination of the two compounds impaired the bees' ability to differentiate the conditioned odour from a novel odour during the memory test. Our results demonstrate that exposure to sublethal doses of combined cholinergic pesticides significantly impairs important behaviours involved in foraging, implying that pollinator population decline could be the result of a failure of neural function of bees exposed to pesticides in agricultural landscapes. PMID:23393272

Antibiotics reduce genetic diversity of core species in the honeybee gut microbiome.

PubMed

Raymann, Kasie; Bobay, Louis-Marie; Moran, Nancy A

2018-04-01

The gut microbiome plays a key role in animal health, and perturbing it can have detrimental effects. One major source of perturbation to microbiomes, in humans and human-associated animals, is exposure to antibiotics. Most studies of how antibiotics affect the microbiome have used amplicon sequencing of highly conserved 16S rRNA sequences, as in a recent study showing that antibiotic treatment severely alters the species-level composition of the honeybee gut microbiome. But because the standard 16S rRNA-based methods cannot resolve closely related strains, strain-level changes could not be evaluated. To address this gap, we used amplicon sequencing of protein-coding genes to assess effects of antibiotics on fine-scale genetic diversity of the honeybee gut microbiota. We followed the population dynamics of alleles within two dominant core species of the bee gut community, Gilliamella apicola and Snodgrassella alvi, following antibiotic perturbation. Whereas we observed a large reduction in genetic diversity in G. apicola, S. alvi diversity was mostly unaffected. The reduction in G. apicola diversity accompanied an increase in the frequency of several alleles, suggesting resistance to antibiotic treatment. We find that antibiotic perturbation can cause major shifts in diversity and that the extent of these shifts can vary substantially across species. Thus, antibiotics impact not only species composition, but also allelic diversity within species, potentially affecting hosts if variants with particular functions are reduced or eliminated. Overall, we show that amplicon sequencing of protein-coding genes, without clustering into operational taxonomic units, provides an accurate picture of the fine-scale dynamics of microbial communities over time. © 2017 John Wiley & Sons Ltd.

Effect of Olfactory Stimulus on the Flight Course of a Honeybee, Apis mellifera, in a Wind Tunnel.

PubMed

Ikeno, Hidetoshi; Akamatsu, Tadaaki; Hasegawa, Yuji; Ai, Hiroyuki

2013-12-31

It is known that the honeybee, Apis mellifera, uses olfactory stimulus as important information for orienting to food sources. Several studies on olfactory-induced orientation flight have been conducted in wind tunnels and in the field. From these studies, optical sensing is used as the main information with the addition of olfactory signals and the navigational course followed by these sensory information. However, it is not clear how olfactory information is reflected in the navigation of flight. In this study, we analyzed the detailed properties of flight when oriented to an odor source in a wind tunnel. We recorded flying bees with a video camera to analyze the flight area, speed, angular velocity and trajectory. After bees were trained to be attracted to a feeder, the flight trajectories with or without the olfactory stimulus located upwind of the feeder were compared. The results showed that honeybees flew back and forth in the proximity of the odor source, and the search range corresponded approximately to the odor spread area. It was also shown that the angular velocity was different inside and outside the odor spread area, and trajectories tended to be bent or curved just outside the area.

Involvement of phosphorylated Apis mellifera CREB in gating a honeybee's behavioral response to an external stimulus

PubMed Central

Gehring, Katrin B.; Heufelder, Karin; Feige, Janina; Bauer, Paul; Dyck, Yan; Ehrhardt, Lea; Kühnemund, Johannes; Bergmann, Anja; Göbel, Josefine; Isecke, Marlene

2016-01-01

The transcription factor cAMP-response element-binding protein (CREB) is involved in neuronal plasticity. Phosphorylation activates CREB and an increased level of phosphorylated CREB is regarded as an indicator of CREB-dependent transcriptional activation. In honeybees (Apis mellifera) we recently demonstrated a particular high abundance of the phosphorylated honeybee CREB homolog (pAmCREB) in the central brain and in a subpopulation of mushroom body neurons. We hypothesize that these high pAmCREB levels are related to learning and memory formation. Here, we tested this hypothesis by analyzing brain pAmCREB levels in classically conditioned bees and bees experiencing unpaired presentations of conditioned stimulus (CS) and unconditioned stimulus (US). We demonstrate that both behavioral protocols display differences in memory formation but do not alter the level of pAmCREB in bee brains directly after training. Nevertheless, we report that bees responding to the CS during unpaired stimulus presentations exhibit higher levels of pAmCREB than nonresponding bees. In addition, Trichostatin A, a histone deacetylase inhibitor that is thought to enhance histone acetylation by CREB-binding protein, increases the bees’ CS responsiveness. We conclude that pAmCREB is involved in gating a bee's behavioral response driven by an external stimulus. PMID:27084927

So Near and Yet So Far: Harmonic Radar Reveals Reduced Homing Ability of Nosema Infected Honeybees

PubMed Central

Wolf, Stephan; McMahon, Dino P.; Lim, Ka S.; Pull, Christopher D.; Clark, Suzanne J.; Paxton, Robert J.; Osborne, Juliet L.

2014-01-01

Pathogens may gain a fitness advantage through manipulation of the behaviour of their hosts. Likewise, host behavioural changes can be a defence mechanism, counteracting the impact of pathogens on host fitness. We apply harmonic radar technology to characterize the impact of an emerging pathogen - Nosema ceranae (Microsporidia) - on honeybee (Apis mellifera) flight and orientation performance in the field. Honeybees are the most important commercial pollinators. Emerging diseases have been proposed to play a prominent role in colony decline, partly through sub-lethal behavioural manipulation of their hosts. We found that homing success was significantly reduced in diseased (65.8%) versus healthy foragers (92.5%). Although lost bees had significantly reduced continuous flight times and prolonged resting times, other flight characteristics and navigational abilities showed no significant difference between infected and non-infected bees. Our results suggest that infected bees express normal flight characteristics but are constrained in their homing ability, potentially compromising the colony by reducing its resource inputs, but also counteracting the intra-colony spread of infection. We provide the first high-resolution analysis of sub-lethal effects of an emerging disease on insect flight behaviour. The potential causes and the implications for both host and parasite are discussed. PMID:25098331

Genetic Structure and Potential Environmental Determinants of Local Genetic Diversity in Japanese Honeybees (Apis cerana japonica)

PubMed Central

Nagamitsu, Teruyoshi; Yasuda, Mika; Saito-Morooka, Fuki; Inoue, Maki N.; Nishiyama, Mio; Goka, Koichi; Sugiura, Shinji; Maeto, Kaoru; Okabe, Kimiko; Taki, Hisatomo

2016-01-01

Declines in honeybee populations have been a recent concern. Although causes of the declines remain unclear, environmental factors may be responsible. We focused on the potential environmental determinants of local populations of wild honeybees, Apis cerana japonica, in Japan. This subspecies has little genetic variation in terms of its mitochondrial DNA sequences, and genetic variations at nuclear loci are as yet unknown. We estimated the genetic structure and environmental determinants of local genetic diversity in nuclear microsatellite genotypes of fathers and mothers, inferred from workers collected at 139 sites. The genotypes of fathers and mothers showed weak isolation by distance and negligible genetic structure. The local genetic diversity was high in central Japan, decreasing toward the peripheries, and depended on the climate and land use characteristics of the sites. The local genetic diversity decreased as the annual precipitation increased, and increased as the proportion of urban and paddy field areas increased. Positive effects of natural forest area, which have also been observed in terms of forager abundance in farms, were not detected with respect to the local genetic diversity. The findings suggest that A. cerana japonica forms a single population connected by gene flow in its main distributional range, and that climate and landscape properties potentially affect its local genetic diversity. PMID:27898704

Genome-wide scans between two honeybee populations reveal putative signatures of human-mediated selection.

PubMed

Parejo, M; Wragg, D; Henriques, D; Vignal, A; Neuditschko, M

2017-12-01

Human-mediated selection has left signatures in the genomes of many domesticated animals, including the European dark honeybee, Apis mellifera mellifera, which has been selected by apiculturists for centuries. Using whole-genome sequence information, we investigated selection signatures in spatially separated honeybee subpopulations (Switzerland, n = 39 and France, n = 17). Three different test statistics were calculated in windows of 2 kb (fixation index, cross-population extended haplotype homozygosity and cross-population composite likelihood ratio) and combined into a recently developed composite selection score. Applying a stringent false discovery rate of 0.01, we identified six significant selective sweeps distributed across five chromosomes covering eight genes. These genes are associated with multiple molecular and biological functions, including regulation of transcription, receptor binding and signal transduction. Of particular interest is a selection signature on chromosome 1, which corresponds to the WNT4 gene, the family of which is conserved across the animal kingdom with a variety of functions. In Drosophila melanogaster, WNT4 alleles have been associated with differential wing, cross vein and abdominal phenotypes. Defining phenotypic characteristics of different Apis mellifera ssp., which are typically used as selection criteria, include colour and wing venation pattern. This signal is therefore likely to be a good candidate for human mediated-selection arising from different applied breeding practices in the two managed populations. © 2017 The Authors. Animal Genetics published by John Wiley & Sons Ltd on behalf of Stichting International Foundation for Animal Genetics.

Lactic acid bacterial symbionts in honeybees - an unknown key to honey's antimicrobial and therapeutic activities.

PubMed

Olofsson, Tobias C; Butler, Èile; Markowicz, Pawel; Lindholm, Christina; Larsson, Lennart; Vásquez, Alejandra

2016-10-01

Could honeybees' most valuable contribution to mankind besides pollination services be alternative tools against infections? Today, due to the emerging antibiotic-resistant pathogens, we are facing a new era of searching for alternative tools against infections. Natural products such as honey have been applied against human's infections for millennia without sufficient scientific evidence. A unique lactic acid bacterial (LAB) microbiota was discovered by us, which is in symbiosis with honeybees and present in large amounts in fresh honey across the world. This work investigates if the LAB symbionts are the source to the unknown factors contributing to honey's properties. Hence, we tested the LAB against severe wound pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and vancomycin-resistant Enterococcus (VRE) among others. We demonstrate a strong antimicrobial activity from each symbiont and a synergistic effect, which counteracted all the tested pathogens. The mechanisms of action are partly shown by elucidating the production of active compounds such as proteins, fatty acids, anaesthetics, organic acids, volatiles and hydrogen peroxide. We show that the symbionts produce a myriad of active compounds that remain in variable amounts in mature honey. Further studies are now required to investigate if these symbionts have a potential in clinical applications as alternative tools against topical human and animal infections. © 2014 The Authors. International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Host Specificity in the Honeybee Parasitic Mite, Varroa spp. in Apis mellifera and Apis cerana

PubMed Central

Beaurepaire, Alexis L.; Dinh, Tam Q.; Cervancia, Cleofas; Moritz, Robin F. A.

2015-01-01

The ectoparasitic mite Varroa destructor is a major global threat to the Western honeybee Apis mellifera. This mite was originally a parasite of A. cerana in Asia but managed to spill over into colonies of A. mellifera which had been introduced to this continent for honey production. To date, only two almost clonal types of V. destructor from Korea and Japan have been detected in A. mellifera colonies. However, since both A. mellifera and A. cerana colonies are kept in close proximity throughout Asia, not only new spill overs but also spill backs of highly virulent types may be possible, with unpredictable consequences for both honeybee species. We studied the dispersal and hybridisation potential of Varroa from sympatric colonies of the two hosts in Northern Vietnam and the Philippines using mitochondrial and microsatellite DNA markers. We found a very distinct mtDNA haplotype equally invading both A. mellifera and A. cerana in the Philippines. In contrast, we observed a complete reproductive isolation of various Vietnamese Varroa populations in A. mellifera and A. cerana colonies even if kept in the same apiaries. In light of this variance in host specificity, the adaptation of the mite to its hosts seems to have generated much more genetic diversity than previously recognised and the Varroa species complex may include substantial cryptic speciation. PMID:26248192

Time-to-death approach to reveal chronic and cumulative toxicity of a fungicide for honeybees not revealed with the standard ten-day test.

PubMed

Simon-Delso, Noa; San Martin, Gilles; Bruneau, Etienne; Hautier, Louis

2018-05-08

Synthetic fungicides are pesticides widely used in agriculture to control phytopathogenic fungi. The systemicity, persistency and intense application of some of these fungicides, such as boscalid, leads to long periods of exposure for honeybees via contaminated water, pollen and nectar. We exposed adult honeybees in the lab to food contaminated with boscalid for 33 days instead of the standard 10-day test. Most of the toxic effects were observed after 10 days. The median time to death (LT 50 ) ranged from 24.9 days (lowest concentration) to 7.1 days (highest concentration) and was significantly shorter in all cases than with the control (32.0 days). The concentration and dietary doses of boscalid inducing 50% mortality (LC 50 and LDD 50 , respectively) decreased strongly with the time of exposure: LC 50  = 14,729 and 1,174 mg/l and LDD 50  = 0.318 and 0.0301 mg bee -1 day -1 at days 8 and 25, respectively. We found evidence of reinforced toxicity when exposure is prolonged, but with an unusual pattern: no cumulative toxicity is observed until 17-18 days, when a point of inflexion appears that suggests a reduced capacity of bees to deal with the toxicant. Our results show the importance of time-to-death experiments rather than fixed-duration studies for evaluating chronic toxicity.

Quantitative weight of evidence assessment of higher-tier studies on the toxicity and risks of neonicotinoid insecticides in honeybees 1: Methods.

PubMed

Solomon, Keith R; Stephenson, Gladys L

2017-01-01

A quantitative weight of evidence (QWoE) methodology was developed and used to assess many higher-tier studies on the effects of three neonicotinoid insecticides: clothianidin (CTD), imidacloprid (IMI), and thiamethoxam (TMX) on honeybees. A general problem formulation, a conceptual model for exposures of honeybees, and an analysis plan were developed. A QWoE methodology was used to characterize the quality of the available studies from the literature and unpublished reports of studies conducted by or for the registrants. These higher-tier studies focused on the exposures of honeybees to neonicotinoids via several matrices as measured in the field as well as the effects in experimentally controlled field studies. Reports provided by Bayer Crop Protection and Syngenta Crop Protection and papers from the open literature were assessed in detail, using predefined criteria for quality and relevance to develop scores (on a relative scale of 0-4) to separate the higher-quality from lower-quality studies and those relevant from less-relevant results. The scores from the QWoEs were summarized graphically to illustrate the overall quality of the studies and their relevance. Through mean and standard errors, this method provided graphical and numerical indications of the quality and relevance of the responses observed in the studies and the uncertainty associated with these two metrics. All analyses were conducted transparently and the derivations of the scores were fully documented. The results of these analyses are presented in three companion papers and the QWoE analyses for each insecticide are presented in detailed supplemental information (SI) in these papers.

Sensitivity of Honeybee Hygroreceptors to Slow Humidity Changes and Temporal Humidity Variation Detected in High Resolution by Mobile Measurements

PubMed Central

Tichy, Harald; Kallina, Wolfgang

2014-01-01

The moist cell and the dry cell on the antenna of the male honeybee were exposed to humidities slowly rising and falling at rates between –1.5%/s and +1.5%/s and at varying amplitudes in the 10 to 90% humidity range. The two cells respond to these slow humidity oscillations with oscillations in impulse frequency which depend not only on instantaneous humidity but also on the rate with which humidity changes. The impulse frequency of each cell was plotted as a function of these two parameters and regression planes were fitted to the data points of single oscillation periods. The regression slopes, which estimate sensitivity, rose with the amplitude of humidity oscillations. During large-amplitude oscillations, moist and dry cell sensitivity for instantaneous humidity and its rate of change was high. During small-amplitude oscillations, their sensitivity for both parameters was low, less exactly reflecting humidity fluctuations. Nothing is known about the spatial and temporal humidity variations a honeybee may encounter when flying through natural environments. Microclimatic parameters (absolute humidity, temperature, wind speed) were measured from an automobile traveling through different landscapes of Lower Austria. Landscape type affected extremes and mean values of humidity. Differences between peaks and troughs of humidity fluctuations were generally smaller in open grassy fields or deciduous forests than in edge habitats or forest openings. Overall, fluctuation amplitudes were small. In this part of the stimulus range, hygroreceptor sensitivity is not optimal for encoding instantaneous humidity and the rate of humidity change. It seems that honeybee's hygroreceptors are specialized for detecting large-amplitude fluctuations that are relevant for a specific behavior, namely, maintaining a sufficiently stable state of water balance. The results suggest that optimal sensitivity of both hygroreceptors is shaped not only by humidity oscillation amplitudes but also

Honeybees use the skyline in orientation.

PubMed

Towne, William F; Ritrovato, Antoinette E; Esposto, Antonina; Brown, Duncan F

2017-07-01

In view-based navigation, animals acquire views of the landscape from various locations and then compare the learned views with current views in order to orient in certain directions or move toward certain destinations. One landscape feature of great potential usefulness in view-based navigation is the skyline, the silhouette of terrestrial objects against the sky, as it is distant, relatively stable and easy to detect. The skyline has been shown to be important in the view-based navigation of ants, but no flying insect has yet been shown definitively to use the skyline in this way. Here, we show that honeybees do indeed orient using the skyline. A feeder was surrounded with an artificial replica of the natural skyline there, and the bees' departures toward the nest were recorded from above with a video camera under overcast skies (to eliminate celestial cues). When the artificial skyline was rotated, the bees' departures were rotated correspondingly, showing that the bees oriented by the artificial skyline alone. We discuss these findings in the context of the likely importance of the skyline in long-range homing in bees, the likely importance of altitude in using the skyline, the likely role of ultraviolet light in detecting the skyline, and what we know about the bees' ability to resolve skyline features. © 2017. Published by The Company of Biologists Ltd.

Somatic Maintenance Resources in the Honeybee Worker Fat Body Are Distributed to Withstand the Most Life-Threatening Challenges at Each Life Stage

PubMed Central

Seehuus, Siri-Christine; Taylor, Simon; Petersen, Kjell; Aamodt, Randi M.

2013-01-01

In a global transcriptome analysis of three natural and three manipulated honeybee worker phenotypes at different ages, we have investigated the distribution of investment in somatic maintenance of the fat body. Gene expression is modulated so that the bees are able to resist the most life-threatening challenges at the actual life stage. Different modes of maintenance and repair are regulated, apparently to meet the environmental challenges most detrimental to survival and reproductive potential for the hive. We observed a broad down-regulation of genomic and cellular maintenance in the short-lived foragers and nurse bees compared to the long-lived winter bees. Our results show that survival and reproduction of the entire hive is given priority over the individual bees, hence supporting the idea of the honeybee society as a superorganism. Our results also fit the disposable soma theory of aging. PMID:23940531

Complex social waves of giant honeybees provoked by a dummy wasp support the special-agent hypothesis.

PubMed

Kastberger, Gerald; Weihmann, Frank; Hoetzl, Thomas

2010-03-01

The social waves in giant honeybees termed as shimmering are more complex than mexican waves. it has been demonstrated1 that shimmering is triggered by special agents at the nest surface. in this paper, we have used a nest that originated by amalgamation of two previously separated nests and stimulated waves by a dummy wasp moved on a miniature cable car. we illustrate the plausibility of the special-agent hypothesis1 also for complex shimmering processes.

Complex social waves of giant honeybees provoked by a dummy wasp support the special-agent hypothesis

PubMed Central

Weihmann, Frank; Hoetzl, Thomas

2010-01-01

The social waves in giant honeybees termed as shimmering are more complex than mexican waves. it has been demonstrated1 that shimmering is triggered by special agents at the nest surface. in this paper, we have used a nest that originated by amalgamation of two previously separated nests and stimulated waves by a dummy wasp moved on a miniature cable car. we illustrate the plausibility of the special-agent hypothesis1 also for complex shimmering processes. PMID:20585516

Role of the Varroa mite in honeybee (Apis mellifera) colony loss: A case study for adverse outcome pathway development with a nonchemical stressor

EPA Science Inventory

Significant honeybee colony losses have been reported across North America and Europe in recent years. A number of factors, both chemical and nonchemical, have been associated with such losses. Adverse outcome pathways (AOPs) provide a conceptual framework to describe and evalu...

7 CFR 322.10 - Inspection; refusal of entry.

Code of Federal Regulations, 2014 CFR

2014-01-01

... SERVICE, DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.10 Inspection; refusal of entry. (a) Shipments of honeybees, honeybee germ plasm, and bees other than honeybees...

7 CFR 322.12 - Risk assessment procedures for approving countries.

Code of Federal Regulations, 2012 CFR

2012-01-01

... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved... United States of honeybees, honeybee germ plasm, or bees other than honeybees from that region. (b) When...

7 CFR 322.10 - Inspection; refusal of entry.

Code of Federal Regulations, 2010 CFR

2010-01-01

... SERVICE, DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.10 Inspection; refusal of entry. (a) Shipments of honeybees, honeybee germ plasm, and bees other than honeybees...

7 CFR 322.10 - Inspection; refusal of entry.

Code of Federal Regulations, 2012 CFR

2012-01-01

... SERVICE, DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.10 Inspection; refusal of entry. (a) Shipments of honeybees, honeybee germ plasm, and bees other than honeybees...

7 CFR 322.12 - Risk assessment procedures for approving countries.

Code of Federal Regulations, 2014 CFR

2014-01-01

... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved... United States of honeybees, honeybee germ plasm, or bees other than honeybees from that region. (b) When...

7 CFR 322.10 - Inspection; refusal of entry.

Code of Federal Regulations, 2011 CFR

2011-01-01

... SERVICE, DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.10 Inspection; refusal of entry. (a) Shipments of honeybees, honeybee germ plasm, and bees other than honeybees...

7 CFR 322.12 - Risk assessment procedures for approving countries.

Code of Federal Regulations, 2010 CFR

2010-01-01

... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved... United States of honeybees, honeybee germ plasm, or bees other than honeybees from that region. (b) When...

7 CFR 322.10 - Inspection; refusal of entry.

Code of Federal Regulations, 2013 CFR

2013-01-01

... SERVICE, DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.10 Inspection; refusal of entry. (a) Shipments of honeybees, honeybee germ plasm, and bees other than honeybees...

7 CFR 322.12 - Risk assessment procedures for approving countries.

Code of Federal Regulations, 2011 CFR

2011-01-01

... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved... United States of honeybees, honeybee germ plasm, or bees other than honeybees from that region. (b) When...

7 CFR 322.12 - Risk assessment procedures for approving countries.

Code of Federal Regulations, 2013 CFR

2013-01-01

... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved... United States of honeybees, honeybee germ plasm, or bees other than honeybees from that region. (b) When...

Spectral inputs and ocellar contributions to a pitch-sensitive descending neuron in the honeybee.

PubMed

Hung, Y-S; van Kleef, J P; Stange, G; Ibbotson, M R

2013-02-01

By measuring insect compensatory optomotor reflexes to visual motion, researchers have examined the computational mechanisms of the motion processing system. However, establishing the spectral sensitivity of the neural pathways that underlie this motion behavior has been difficult, and the contribution of the simple eyes (ocelli) has been rarely examined. In this study we investigate the spectral response properties and ocellar inputs of an anatomically identified descending neuron (DNII(2)) in the honeybee optomotor pathway. Using a panoramic stimulus, we show that it responds selectively to optic flow associated with pitch rotations. The neuron is also stimulated with a custom-built light-emitting diode array that presented moving bars that were either all-green (spectrum 500-600 nm, peak 530 nm) or all-short wavelength (spectrum 350-430 nm, peak 380 nm). Although the optomotor response is thought to be dominated by green-sensitive inputs, we show that DNII(2) is equally responsive to, and direction selective to, both green- and short-wavelength stimuli. The color of the background image also influences the spontaneous spiking behavior of the cell: a green background produces significantly higher spontaneous spiking rates. Stimulating the ocelli produces strong modulatory effects on DNII(2), significantly increasing the amplitude of its responses in the preferred motion direction and decreasing the response latency by adding a directional, short-latency response component. Our results suggest that the spectral sensitivity of the optomotor response in honeybees may be more complicated than previously thought and that ocelli play a significant role in shaping the timing of motion signals.

A comparison of honeybee (Apis mellifera) queen, worker and drone larvae by RNA-Seq.

PubMed

He, Xu-Jiang; Jiang, Wu-Jun; Zhou, Mi; Barron, Andrew B; Zeng, Zhi-Jiang

2017-11-06

Honeybees (Apis mellifera) have haplodiploid sex determination: males develop from unfertilized eggs and females develop from fertilized ones. The differences in larval food also determine the development of females. Here we compared the total somatic gene expression profiles of 2-day and 4-day-old drone, queen and worker larvae by RNA-Seq. The results from a co-expression network analysis on all expressed genes showed that 2-day-old drone and worker larvae were closer in gene expression profiles than 2-day-old queen larvae. This indicated that for young larvae (2-day-old) environmental factors such as larval diet have a greater effect on gene expression profiles than ploidy or sex determination. Drones had the most distinct gene expression profiles at the 4-day larval stage, suggesting that haploidy, or sex dramatically affects the gene expression of honeybee larvae. Drone larvae showed fewer differences in gene expression profiles at the 2-day and 4-day time points than the worker and queen larval comparisons (598 against 1190 and 1181), suggesting a different pattern of gene expression regulation during the larval development of haploid males compared to diploid females. This study indicates that early in development the queen caste has the most distinct gene expression profile, perhaps reflecting the very rapid growth and morphological specialization of this caste compared to workers and drones. Later in development the haploid male drones have the most distinct gene expression profile, perhaps reflecting the influence of ploidy or sex determination on gene expression. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Factors influencing the prevalence and infestation levels of Varroa destructor in honeybee colonies in two highland agro-ecological zones of Uganda.

PubMed

Chemurot, Moses; Akol, Anne M; Masembe, Charles; de Smet, Lina; Descamps, Tine; de Graaf, Dirk C

2016-04-01

Varroa mites are ecto-parasites of honeybees and are a threat to the beekeeping industry. We identified the haplotype of Varroa mites and evaluated potential factors that influence their prevalence and infestation levels in the eastern and western highland agro-ecological zones of Uganda. This was done by collecting samples of adult worker bees between December 2014 and September 2015 in two sampling moments. Samples of bees were screened for Varroa using the ethanol wash method and the mites were identified by molecular techniques. All DNA sequences obtained from sampled mite populations in the two zones were 100 % identical to the Korean Haplotype (AF106899). Mean mite prevalence in the apiaries was 40 and 53 % for the western and eastern zones, respectively, during the first sampling. Over the second sampling, mean mite prevalence increased considerably in the western (59 %) but not in the eastern (51 %) zone. Factors that were associated with Varroa mite infestation levels include altitude, nature of apiary slope and apiary management practices during the first sampling. Our results further showed that Varroa mites were spreading from lower to higher elevations. Feral colonies were also infested with Varroa mites at infestation levels not significantly different from those in managed colonies. Colony productivity and strength were not correlated to mite infestation levels. We recommend a long-term Varroa mite monitoring strategy in areas of varying landscape and land use factors for a clear understanding of possible changes in mite infestation levels among African honeybees for informed decision making.

Characterization of the 5-HT1A receptor of the honeybee (Apis mellifera) and involvement of serotonin in phototactic behavior.

PubMed

Thamm, Markus; Balfanz, Sabine; Scheiner, Ricarda; Baumann, Arnd; Blenau, Wolfgang

2010-07-01

Serotonin plays a key role in modulating various physiological and behavioral processes in both protostomes and deuterostomes. The vast majority of serotonin receptors belong to the superfamily of G-protein-coupled receptors. We report the cloning of a cDNA from the honeybee (Am5-ht1A) sharing high similarity with members of the 5-HT(1) receptor class. Activation of Am5-HT(1A) by serotonin inhibited the production of cAMP in a dose-dependent manner (EC(50) = 16.9 nM). Am5-HT(1A) was highly expressed in brain regions known to be involved in visual information processing. Using in vivo pharmacology, we could demonstrate that Am5-HT(1A) receptor ligands had a strong impact on the phototactic behavior of individual bees. The data presented here mark the first comprehensive study-from gene to behavior-of a 5-HT(1A) receptor in the honeybee, paving the way for the eventual elucidation of additional roles of this receptor subtype in the physiology and behavior of this social insect.

Effect of a thymol application on olfactory memory and gene expression levels in the brain of the honeybee Apis mellifera.

PubMed

Bonnafé, Elsa; Drouard, Florian; Hotier, Lucie; Carayon, Jean-Luc; Marty, Pierre; Treilhou, Michel; Armengaud, Catherine

2015-06-01

Essential oils are used by beekeepers to control the Varroa mites that infest honeybee colonies. So, bees can be exposed to thymol formulations in the hive. The effects of the monoterpenoid thymol were explored on olfactory memory and gene expression in the brain of the honeybee. In bees previously exposed to thymol (10 or 100 ng/bee), the specificity of the response to the conditioned stimulus (CS) was lost 24 h after learning. Besides, the octopamine receptor OA1 gene Amoa1 showed a significant decrease of expression 3 h after exposure with 10 or 100 ng/bee of thymol. With the same doses, expression of Rdl gene, coding for a GABA receptor subunit, was not significantly modified but the trpl gene was upregulated 1 and 24 h after exposure to thymol. These data indicated that the genes coding for the cellular targets of thymol could be rapidly regulated after exposure to this molecule. Memory and sensory processes should be investigated in bees after chronic exposure in the hive to thymol-based preparations.

7 CFR 322.11 - Ports of entry.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.11 Ports of entry. Shipments of honeybees, honeybee germ plasm, and bees other than honeybees imported under this subpart may...

7 CFR 322.11 - Ports of entry.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.11 Ports of entry. Shipments of honeybees, honeybee germ plasm, and bees other than honeybees imported under this subpart may...

7 CFR 322.9 - Mailed packages.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.9 Mailed packages. (a) If you import a package of honeybees, honeybee germ plasm, or bees other than honeybees under...

7 CFR 322.11 - Ports of entry.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.11 Ports of entry. Shipments of honeybees, honeybee germ plasm, and bees other than honeybees imported under this subpart may...

7 CFR 322.9 - Mailed packages.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.9 Mailed packages. (a) If you import a package of honeybees, honeybee germ plasm, or bees other than honeybees under...

7 CFR 322.9 - Mailed packages.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.9 Mailed packages. (a) If you import a package of honeybees, honeybee germ plasm, or bees other than honeybees under...

7 CFR 322.9 - Mailed packages.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.9 Mailed packages. (a) If you import a package of honeybees, honeybee germ plasm, or bees other than honeybees under...

7 CFR 322.11 - Ports of entry.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.11 Ports of entry. Shipments of honeybees, honeybee germ plasm, and bees other than honeybees imported under this subpart may...

7 CFR 322.11 - Ports of entry.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.11 Ports of entry. Shipments of honeybees, honeybee germ plasm, and bees other than honeybees imported under this subpart may...

7 CFR 322.9 - Mailed packages.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.9 Mailed packages. (a) If you import a package of honeybees, honeybee germ plasm, or bees other than honeybees under...

Concentrations of imidacloprid and thiamethoxam in pollen, nectar and leaves from seed-dressed cotton crops and their potential risk to honeybees (Apis mellifera L.).

PubMed

Jiang, Jiangong; Ma, Dicheng; Zou, Nan; Yu, Xin; Zhang, Zhengqun; Liu, Feng; Mu, Wei

2018-06-01

Neonicotinoid insecticides (NIs) have recently been recognized as co-factors in the decline of honeybee colonies because most neonicotinoids are systemic and can transfer into the pollen and nectar of many pollinated crops. In this study, we collected pollen, nectar and leaves from a cotton crop treated with imidacloprid and thiamethoxam to measure the residue levels of these two NIs at different application doses during the flowering period. Then, the residual data were used to assess the risk posed by the systemic insecticides to honeybees following mandated methods published by the European Food Safety Authority (EFSA), and a highly toxic risk to honeybees was highlighted. Imidacloprid was found in both pollen and nectar samples, whereas thiamethoxam was found in 90% of pollen samples and over 60% of nectar samples. Analysis of the pollen and nectar revealed residual amounts of imidacloprid ranging from 1.61 to 64.58 ng g -1 in the pollen and from not detected (ND) to 1.769 ng g -1 in the nectar. By comparison, the thiamethoxam concentrations in pollen and nectar ranged from ND to 14.521 ng g -1 and from ND to 4.285 ng g -1 , respectively. The results of this study provide information on the transfer of two NIs from seed treatment to areas of the plant and provides an understanding of the potential exposure of the bee and other pollinators to systemic insecticides. Copyright © 2018 Elsevier Ltd. All rights reserved.

Applying an Activity Theory Lens to Designing Instruction for Learning about the Structure, Behavior, and Function of a Honeybee System

ERIC Educational Resources Information Center

Danish, Joshua A.

2014-01-01

This article reports on a study in which activity theory was used to design, implement, and analyze a 10-week curriculum unit about how honeybees collect nectar with a particular focus on complex systems concepts. Students (n = 42) in a multi-year kindergarten and 1st-grade classroom participated in this study as part of their 10 regular classroom…

A typing scheme for the honeybee pathogen Melissococcus plutonius allows detection of disease transmission events and a study of the distribution of variants.

PubMed

Haynes, Edward; Helgason, Thorunn; Young, J Peter W; Thwaites, Richard; Budge, Giles E

2013-08-01

Melissococcus plutonius is the bacterial pathogen that causes European Foulbrood of honeybees, a globally important honeybee brood disease. We have used next-generation sequencing to identify highly polymorphic regions in an otherwise genetically homogenous organism, and used these loci to create a modified MLST scheme. This synthesis of a proven typing scheme format with next-generation sequencing combines reliability and low costs with insights only available from high-throughput sequencing technologies. Using this scheme we show that the global distribution of M.plutonius variants is not uniform. We use the scheme in epidemiological studies to trace movements of infective material around England, insights that would have been impossible to confirm without the typing scheme. We also demonstrate the persistence of local variants over time. © 2013 Crown copyright. Reproduced with the permission of the Controller of Her Majesty's Stationary Office/Queen’s Printer for Scotland and Food and Environment Research Agency.

Neonicotinoid pesticides can reduce honeybee colony genetic diversity

PubMed Central

Troxler, Aline; Retschnig, Gina; Gauthier, Laurent; Straub, Lars; Moritz, Robin F. A.; Neumann, Peter; Williams, Geoffrey R.

2017-01-01

Neonicotinoid insecticides can cause a variety of adverse sub-lethal effects in bees. In social species such as the honeybee, Apis mellifera, queens are essential for reproduction and colony functioning. Therefore, any negative effect of these agricultural chemicals on the mating success of queens may have serious consequences for the fitness of the entire colony. Queens were exposed to the common neonicotinoid pesticides thiamethoxam and clothianidin during their developmental stage. After mating, their spermathecae were dissected to count the number of stored spermatozoa. Furthermore, their worker offspring were genotyped with DNA microsatellites to determine the number of matings and the genotypic composition of the colony. Colonies providing the male mating partners were also inferred. Both neonicotinoid and control queens mated with drones originating from the same drone source colonies, and stored similar number of spermatozoa. However, queens reared in colonies exposed to both neonicotinoids experienced fewer matings. This resulted in a reduction of the genetic diversity in their colonies (i.e. higher intracolonial relatedness). As decreased genetic diversity among worker bees is known to negatively affect colony vitality, neonicotinoids may have a cryptic effect on colony health by reducing the mating frequency of queens. PMID:29059234

Worker piping triggers hissing for coordinated colony defence in the dwarf honeybee Apis florea.

PubMed

Sen Sarma, Moushumi; Fuchs, Stefan; Werber, Christian; Tautz, Jürgen

2002-01-01

Defending a large social insect colony containing several thousands of workers requires the simultaneous action of many individuals. Ideally this action involves communication between the workers, enabling coordinated action and a fast response. The Asian dwarf honeybee, Apis florea, is a small honeybee with an open nesting habit and a comparatively small colony size, features that leave them particularly exposed to predators. We describe here a novel defence response of these bees in which the emission of an initial warning signal from one individual ("piping") is followed 0.3 to 0.7 seconds later by a general response from a large number of bees ("hissing"). Piping is audible to the human ear, with a fundamental frequency of 384 +/- 31Hz and lasting for 0.82 +/- 0.35 seconds. Hissing is a broad band, noisy signal, clearly audible to the human observer and produced by slight but visible movements of the bees' wings. Hissing begins in individuals close to the piping bee, spreads rapidly to neighbours and results in an impressive coordinated crescendo occasionally involving the entire colony. Piping and hissing are accompanied by a marked decrease, or even cessation, of worker activities such as forager dancing and departures from the colony. We show that whereas hissing of the colony can be elicited without piping, the sequential and correlated piping and hissing response is specific to the presence of potential predators close to the colony. We suggest that the combined audio-visual effect of the hissing might deter small predators, while the cessation of flight activity could decrease the risk of predation by birds and insects which prey selectively on flying bees.

Energetic Optimisation of Foraging Honeybees: Flexible Change of Strategies in Response to Environmental Challenges

PubMed Central

Stabentheiner, Anton; Kovac, Helmut

2014-01-01

Heterothermic insects like honeybees, foraging in a variable environment, face the challenge of keeping their body temperature high to enable immediate flight and to promote fast exploitation of resources. Because of their small size they have to cope with an enormous heat loss and, therefore, high costs of thermoregulation. This calls for energetic optimisation which may be achieved by different strategies. An ‘economizing’ strategy would be to reduce energetic investment whenever possible, for example by using external heat from the sun for thermoregulation. An ‘investment-guided’ strategy, by contrast, would be to invest additional heat production or external heat gain to optimize physiological parameters like body temperature which promise increased energetic returns. Here we show how honeybees balance these strategies in response to changes of their local microclimate. In a novel approach of simultaneous measurement of respiration and body temperature foragers displayed a flexible strategy of thermoregulatory and energetic management. While foraging in shade on an artificial flower they did not save energy with increasing ambient temperature as expected but acted according to an ‘investment-guided’ strategy, keeping the energy turnover at a high level (∼56–69 mW). This increased thorax temperature and speeded up foraging as ambient temperature increased. Solar heat was invested to increase thorax temperature at low ambient temperature (‘investment-guided’ strategy) but to save energy at high temperature (‘economizing’ strategy), leading to energy savings per stay of ∼18–76% in sunshine. This flexible economic strategy minimized costs of foraging, and optimized energetic efficiency in response to broad variation of environmental conditions. PMID:25162211

Honeybee (Apis mellifera)-associated bacterial community affected by American foulbrood: detection of Paenibacillus larvae via microbiome analysis.

PubMed

Erban, Tomas; Ledvinka, Ondrej; Kamler, Martin; Nesvorna, Marta; Hortova, Bronislava; Tyl, Jan; Titera, Dalibor; Markovic, Martin; Hubert, Jan

2017-07-11

Honeybee (Apis mellifera L.) workers act as passive vectors of Paenibacillus larvae spores, which cause the quarantine disease American foulbrood (AFB). We assessed the relative proportions of P. larvae within the honeybee microbiome using metabarcoding analysis of the 16 S rRNA gene. The microbiome was analyzed in workers outside of the AFB zone (control - AFB0), in workers from asymptomatic colonies in an AFB apiary (AFB1), and in workers from colonies exhibiting clinical AFB symptoms (AFB2). The microbiome was processed for the entire community and for a cut-off microbiome comprising pathogenic/environmental bacteria following the removal of core bacterial sequences; varroosis levels were considered in the statistical analysis. No correlation was observed between AFB status and varroosis level, but AFB influenced the worker bee bacterial community, primarily the pathogenic/environmental bacteria. There was no significant difference in the relative abundance of P. larvae between the AFB1 and AFB0 colonies, but we did observe a 9-fold increase in P. larvae abundance in AFB2 relative to the abundance in AFB1. The relative sequence numbers of Citrobacter freundii and Hafnia alvei were higher in AFB2 and AFB1 than in AFB0, whereas Enterococcus faecalis, Klebsiella oxytoca, Spiroplasma melliferum and Morganella morganii were more abundant in AFB0 and AFB1 than in AFB2.

Oriental orchid (Cymbidium floribundum) attracts the Japanese honeybee (Apis cerana japonica) with a mixture of 3-hydroxyoctanoic acid and 10-hydroxy- (E)-2-decenoic acid.

PubMed

Sugahara, Michio; Izutsu, Kazunari; Nishimura, Yasuichiro; Sakamoto, Fumio

2013-02-01

The flower of the oriental orchid Cymbidium floribundum is known to attract the Japanese honeybee Apis cerana japonica. This effect is observed not only in workers but also drones and queens; that is, it attracts even swarming and absconding bees. A mixture of 3-hydroxyoctanoic acid (3-HOAA) and 10-hydroxy-(E)-2-decenoic acid (10-HDA) was identified as the active principles from the orchid flower, whereas these compounds individually have no such activity. Both compounds are also mandibular gland components of worker honeybees with related compounds. This strongly supports the idea that orchid flowers mimic bee secretions, although the ecological consequences of this relationship remain unknown. Because the flower is used to capture swarms, the present identification may contribute to the development of new techniques in traditional beekeeping for Japanese bees as well as A. cerana in Southeast Asia.

Respiration of resting honeybees

PubMed Central

Kovac, Helmut; Stabentheiner, Anton; Hetz, Stefan K.; Petz, Markus; Crailsheim, Karl

2011-01-01

The relation between the respiratory activity of resting honeybees and ambient temperature (Ta) was investigated in the range of 5–40 °C. Bees were kept in a temperature controlled flow through respirometer chamber where their locomotor and endothermic activity, as well as abdominal ventilatory movements was recorded by infrared thermography. Surprisingly, true resting bees were often weakly endothermic (thorax surface up to 2.8 °C warmer than abdomen) at a Ta of 14–30 °C. Above 33 °C many bees cooled their body via evaporation from their mouthparts. A novel mathematical model allows description of the relationship of resting (standard) metabolic rate and temperature across the entire functional temperature range of bees. In chill coma (<11 °C) bees were ectothermic and CO2 release was mostly continuous. CO2 release rate (nl s−1) decreased from 9.3 at 9.7 °C to 5.4 at 5 °C. At a Ta of >11 °C CO2 was released discontinuously. In the bees’ active temperature range mean CO2 production rate (nl s−1) increased sigmoidally (10.6 at 14.1 °C, 24.1 at 26.5 °C, and 55.2 at 38.1 °C), coming to a halt towards the upper lethal temperature. This was primarily accomplished by an exponential increase in gas exchange frequency (0.54 and 3.1 breaths min−1 at 14.1 and 38.1 °C) but not in released CO2 volume per respiratory cycle (1487 and 1083 nl cycle−1 at 14.1 and 38.1 °C). Emission of CO2 bursts was mostly (98%) accompanied by abdominal ventilation movements even in small CO2 bursts. Larger bursts coincided with a longer duration of active ventilation. An increased amount of CO2 expelled per unit time of ventilation indicates a higher efficiency of ventilation at high ambient temperatures. PMID:17707395

Investigation of span-chordwise bending anisotropy of honeybee forewings

PubMed Central

Ning, JianGuo; Ma, Yun; Zhang, PengFei

2017-01-01

ABSTRACT In this study, the spanwise and chordwise bending stiffness EI of honeybee forewings were measured by a cantilevered bending test. The test results indicate that the spanwise EI of the forewing is two orders of magnitude larger than the chordwise EI. Three structural aspects result in this span-chordwise bending anisotropy: the distribution of resilin patches, the corrugation along the span and the leading edge vein of the venation. It was found that flexion lines formed by resilin patches revealed through fluorescence microscopy promoted the chordwise bending of the forewing during flapping flight. Furthermore, the corrugation of the wing and leading edge veins of the venation, revealed by micro-computed tomography, determines the relatively greater spanwise EI of the forewing. The span-chordwise anisotropy exerts positive structural and aerodynamic influences on the wing. In summary, this study potentially assists researchers in understanding the bending characteristics of insect wings and might be an important reference for the design and manufacture of bio-inspired wings for flapping micro aerial vehicles. PMID:28396486

Error in the Honeybee Waggle Dance Improves Foraging Flexibility

PubMed Central

Okada, Ryuichi; Ikeno, Hidetoshi; Kimura, Toshifumi; Ohashi, Mizue; Aonuma, Hitoshi; Ito, Etsuro

2014-01-01

The honeybee waggle dance communicates the location of profitable food sources, usually with a certain degree of error in the directional information ranging from 10–15° at the lower margin. We simulated one-day colonial foraging to address the biological significance of information error in the waggle dance. When the error was 30° or larger, the waggle dance was not beneficial. If the error was 15°, the waggle dance was beneficial when the food sources were scarce. When the error was 10° or smaller, the waggle dance was beneficial under all the conditions tested. Our simulation also showed that precise information (0–5° error) yielded great success in finding feeders, but also caused failures at finding new feeders, i.e., a high-risk high-return strategy. The observation that actual bees perform the waggle dance with an error of 10–15° might reflect, at least in part, the maintenance of a successful yet risky foraging trade-off. PMID:24569525

A Comparative Study of Relational Learning Capacity in Honeybees (Apis mellifera) and Stingless Bees (Melipona rufiventris)

PubMed Central

Moreno, Antonio Mauricio; de Souza, Deisy das Graças; Reinhard, Judith

2012-01-01

Background Learning of arbitrary relations is the capacity to acquire knowledge about associations between events or stimuli that do not share any similarities, and use this knowledge to make behavioural choices. This capacity is well documented in humans and vertebrates, and there is some evidence it exists in the honeybee (Apis mellifera). However, little is known about whether the ability for relational learning extends to other invertebrates, although many insects have been shown to possess excellent learning capacities in spite of their small brains. Methodology/Principal Findings Using a symbolic matching-to-sample procedure, we show that the honeybee Apis mellifera rapidly learns arbitrary relations between colours and patterns, reaching 68.2% correct choice for pattern-colour relations and 73.3% for colour-pattern relations. However, Apis mellifera does not transfer this knowledge to the symmetrical relations when the stimulus order is reversed. A second bee species, the stingless bee Melipona rufiventris from Brazil, seems unable to learn the same arbitrary relations between colours and patterns, although it exhibits excellent discrimination learning. Conclusions/Significance Our results confirm that the capacity for learning arbitrary relations is not limited to vertebrates, but even insects with small brains can perform this learning task. Interestingly, it seems to be a species-specific ability. The disparity in relational learning performance between the two bee species we tested may be linked to their specific foraging and recruitment strategies, which evolved in adaptation to different environments. PMID:23251542

A comparative study of relational learning capacity in honeybees (Apis mellifera) and stingless bees (Melipona rufiventris).

PubMed

Moreno, Antonio Mauricio; de Souza, Deisy das Graças; Reinhard, Judith

2012-01-01

Learning of arbitrary relations is the capacity to acquire knowledge about associations between events or stimuli that do not share any similarities, and use this knowledge to make behavioural choices. This capacity is well documented in humans and vertebrates, and there is some evidence it exists in the honeybee (Apis mellifera). However, little is known about whether the ability for relational learning extends to other invertebrates, although many insects have been shown to possess excellent learning capacities in spite of their small brains. Using a symbolic matching-to-sample procedure, we show that the honeybee Apis mellifera rapidly learns arbitrary relations between colours and patterns, reaching 68.2% correct choice for pattern-colour relations and 73.3% for colour-pattern relations. However, Apis mellifera does not transfer this knowledge to the symmetrical relations when the stimulus order is reversed. A second bee species, the stingless bee Melipona rufiventris from Brazil, seems unable to learn the same arbitrary relations between colours and patterns, although it exhibits excellent discrimination learning. Our results confirm that the capacity for learning arbitrary relations is not limited to vertebrates, but even insects with small brains can perform this learning task. Interestingly, it seems to be a species-specific ability. The disparity in relational learning performance between the two bee species we tested may be linked to their specific foraging and recruitment strategies, which evolved in adaptation to different environments.

Airflow and optic flow mediate antennal positioning in flying honeybees

PubMed Central

Roy Khurana, Taruni; Sane, Sanjay P

2016-01-01

To maintain their speeds during navigation, insects rely on feedback from their visual and mechanosensory modalities. Although optic flow plays an essential role in speed determination, it is less reliable under conditions of low light or sparse landmarks. Under such conditions, insects rely on feedback from antennal mechanosensors but it is not clear how these inputs combine to elicit flight-related antennal behaviours. We here show that antennal movements of the honeybee, Apis mellifera, are governed by combined visual and antennal mechanosensory inputs. Frontal airflow, as experienced during forward flight, causes antennae to actively move forward as a sigmoidal function of absolute airspeed values. However, corresponding front-to-back optic flow causes antennae to move backward, as a linear function of relative optic flow, opposite the airspeed response. When combined, these inputs maintain antennal position in a state of dynamic equilibrium. DOI: http://dx.doi.org/10.7554/eLife.14449.001 PMID:27097104

Detection of chronic bee paralysis virus and acute bee paralysis virus in Uruguayan honeybees.

PubMed

Antúnez, Karina; D' Alessandro, Bruno; Corbella, Eduardo; Zunino, Pablo

2005-09-01

Chronic bee paralysis virus (CBPV) causes a disease characterized by trembling, flightless, and crawling bees, while Acute bee paralysis virus (ABPV) is commonly detected in apparently healthy colonies, usually associated to Varroa destructor. Both viruses had been detected in most regions of the world, except in South America. In this work, we detected CBPV and ABPV in samples of Uruguayan honeybees by RT-PCR. The detection of both viruses in different provinces and the fact that most of the analyzed samples were infected, suggest that, they are widely spread in the region. This is the first record of the presence of CBPV and ABPV in Uruguay and South America.

Molecular determinants of caste differentiation in the highly eusocial honeybee Apis mellifera.

PubMed

Barchuk, Angel R; Cristino, Alexandre S; Kucharski, Robert; Costa, Luciano F; Simões, Zilá L P; Maleszka, Ryszard

2007-06-18

In honeybees, differential feeding of female larvae promotes the occurrence of two different phenotypes, a queen and a worker, from identical genotypes, through incremental alterations, which affect general growth, and character state alterations that result in the presence or absence of specific structures. Although previous studies revealed a link between incremental alterations and differential expression of physiometabolic genes, the molecular changes accompanying character state alterations remain unknown. By using cDNA microarray analyses of >6,000 Apis mellifera ESTs, we found 240 differentially expressed genes (DEGs) between developing queens and workers. Many genes recorded as up-regulated in prospective workers appear to be unique to A. mellifera, suggesting that the workers' developmental pathway involves the participation of novel genes. Workers up-regulate more developmental genes than queens, whereas queens up-regulate a greater proportion of physiometabolic genes, including genes coding for metabolic enzymes and genes whose products are known to regulate the rate of mass-transforming processes and the general growth of the organism (e.g., tor). Many DEGs are likely to be involved in processes favoring the development of caste-biased structures, like brain, legs and ovaries, as well as genes that code for cytoskeleton constituents. Treatment of developing worker larvae with juvenile hormone (JH) revealed 52 JH responsive genes, specifically during the critical period of caste development. Using Gibbs sampling and Expectation Maximization algorithms, we discovered eight overrepresented cis-elements from four gene groups. Graph theory and complex networks concepts were adopted to attain powerful graphical representations of the interrelation between cis-elements and genes and objectively quantify the degree of relationship between these entities. We suggest that clusters of functionally related DEGs are co-regulated during caste development in honeybees

Molecular determinants of caste differentiation in the highly eusocial honeybee Apis mellifera

PubMed Central

Barchuk, Angel R; Cristino, Alexandre S; Kucharski, Robert; Costa, Luciano F; Simões, Zilá LP; Maleszka, Ryszard

2007-01-01

Background In honeybees, differential feeding of female larvae promotes the occurrence of two different phenotypes, a queen and a worker, from identical genotypes, through incremental alterations, which affect general growth, and character state alterations that result in the presence or absence of specific structures. Although previous studies revealed a link between incremental alterations and differential expression of physiometabolic genes, the molecular changes accompanying character state alterations remain unknown. Results By using cDNA microarray analyses of >6,000 Apis mellifera ESTs, we found 240 differentially expressed genes (DEGs) between developing queens and workers. Many genes recorded as up-regulated in prospective workers appear to be unique to A. mellifera, suggesting that the workers' developmental pathway involves the participation of novel genes. Workers up-regulate more developmental genes than queens, whereas queens up-regulate a greater proportion of physiometabolic genes, including genes coding for metabolic enzymes and genes whose products are known to regulate the rate of mass-transforming processes and the general growth of the organism (e.g., tor). Many DEGs are likely to be involved in processes favoring the development of caste-biased structures, like brain, legs and ovaries, as well as genes that code for cytoskeleton constituents. Treatment of developing worker larvae with juvenile hormone (JH) revealed 52 JH responsive genes, specifically during the critical period of caste development. Using Gibbs sampling and Expectation Maximization algorithms, we discovered eight overrepresented cis-elements from four gene groups. Graph theory and complex networks concepts were adopted to attain powerful graphical representations of the interrelation between cis-elements and genes and objectively quantify the degree of relationship between these entities. Conclusion We suggest that clusters of functionally related DEGs are co-regulated during

Isoform-specific modulation of the chemical sensitivity of conserved TRPA1 channel in the major honeybee ectoparasitic mite, Tropilaelaps mercedesae

PubMed Central

Dong, Xiaofeng; Kashio, Makiko; Peng, Guangda; Wang, Xinyue; Tominaga, Makoto

2016-01-01

We identified and characterized the TRPA1 channel of Tropilaelaps mercedesae (TmTRPA1), one of two major species of honeybee ectoparasitic mite. Three TmTRPA1 isoforms with unique N-terminal sequences were activated by heat, and the isoform highly expressed in the mite's front legs, TmTRPA1b, was also activated by 27 plant-derived compounds including electrophiles. This suggests that the heat- and electrophile-dependent gating mechanisms as nocisensitive TRPA1 channel are well conserved between arthropod species. Intriguingly, one TmTRPA1 isoform, TmTRPA1a, was activated by only six compounds compared with two other isoforms, demonstrating that the N-terminal sequences are critical determinants for the chemical sensitivity. This is the first example of isoform-specific modulation of chemical sensitivity of TRPA1 channel in one species. α-terpineol showed repellent activity towards T. mercedesae in a laboratory assay and repressed T. mercedesae entry for reproduction into the brood cells with fifth instar larvae in hives. Thus, α-terpineol could be used as the potential compound to control two major honeybee ectoparasitic mites, T. mercedesae and Varroa destructor, in the apiculture industry. PMID:27307515

Establishment of Characteristic Gut Bacteria during Development of the Honeybee Worker

PubMed Central

Moy, Jamie

2012-01-01

Previous surveys have shown that adult honeybee (Apis mellifera) workers harbor a characteristic gut microbiota that may play a significant role in bee health. For three major phylotypes within this microbiota, we have characterized distributions and abundances across the life cycle and among gut organs. These distinctive phylotypes, called Beta, Firm-5, and Gamma-1 (BFG), were assayed using quantitative PCR, fluorescent in situ hybridization (FISH) microscopy, and the experimental manipulation of inoculation routes within developing bees. Adult workers (9 to 30 days posteclosion) contained a large BFG microbiota with a characteristic distribution among gut organs. The crop and midgut were nearly devoid of these phylotypes, while the ileum and rectum together contained more than 95% of the total BFG microbiota. The ileum contained a stratified community in which the Beta and Gamma-1 phylotypes dominated, filling the longitudinal folds of this organ. Deep sequencing of 16S rRNA genes showed clear differences among communities in midgut, ileum, and rectum. In contrast with older workers, larvae and newly emerged workers contain few or no bacteria, and their major food source, bee bread, lacks most characteristic phylotypes. In experiments aimed at determining the route of inoculation, newly emerged workers (NEWs) sometimes acquired the typical phylotypes through contact with older workers, contact with the hive, and emergence from the brood cell; however, transmission was patchy in these assays. Our results outline a colonization pattern for the characteristic phylotypes through A. mellifera ontogeny. We propose the names “Candidatus Snodgrassella alvi” and “Candidatus Gilliamella apicola” for the Beta and Gamma-1 phylotypes, respectively. PMID:22307297

Oxygen consumption and body temperature of active and resting honeybees.

PubMed

Stabentheiner, Auton; Vollmann, Jutta; Kovac, Helmut; Crailsheim, Karl

2003-09-01

We measured the energy turnover (oxygen consumption) of honeybees (Apis mellifera carnica), which were free to move within Warburg vessels. Oxygen consumption of active bees varied widely depending on ambient temperature and level of activity, but did not differ between foragers (>18 d) and middle-aged hive bees (7-10 d). In highly active bees, which were in an endothermic state ready for flight, it decreased almost linearly, from a maximum of 131.4 microl O(2) min(-1) at 15 degrees C ambient temperature to 81.1 microl min(-1) at 25 degrees C, and reached a minimum of 29.9 microl min(-1) at 40 degrees C. In bees with low activity, it decreased from 89.3 microl O(2) min(-1) at 15 degrees C to 47.9 microl min(-1) at 25 degrees C and 14.7 microl min(-1) at 40 degrees C. Thermographic measurements of body temperature showed that with increasing activity, the bees invested more energy to regulate the thorax temperature at increasingly higher levels (38.8-41.2 degrees C in highly active bees) and were more accurate. Resting metabolism was determined in young bees of 1-7 h age, which are not yet capable of endothermic heat production with their flight muscles. Their energy turnover increased from 0.21 microl O(2) min(-1) at 10 degrees C to 0.38 microl min(-1) at 15 degrees C, 1.12 microl min(-1) at 25 degrees C, and 3.03 microl min(-1) at 40 degrees C. At 15, 25 and 40 degrees C, this was 343, 73 and 10 times below the values of the highly active bees, respectively. The Q(10) value of the resting bees, however, was not constant but varied in a U-shaped manner with ambient temperature. It decreased from 4.24 in the temperature range 11-21 degrees C to 1.35 in the range 21-31 degrees C, and increased again to 2.49 in the range 30-40 degrees C. We conclude that attempts to describe the temperature dependence of the resting metabolism of honeybees by Q(10) values can lead to considerable errors if the measurements are performed at only two temperatures. An acceptable

Definitive identification of magnetite nanoparticles in the abdomen of the honeybee Apis mellifera

NASA Astrophysics Data System (ADS)

Desoil, M.; Gillis, P.; Gossuin, Y.; Pankhurst, Q. A.; Hautot, D.

2005-01-01

The biogenic magnetic properties of the honeybee Apis mellifera were investigated with a view to understanding the bee's physiological response to magnetic fields. The magnetisations of bee abdomens on one hand, and heads and thoraxes on the other hand, were measured separately as functions of temperature and field. Both the antiferromagnetic responses of the ferrihydrite cores of the iron storage protein ferritin, and the ferrimagnetic responses of nanoscale magnetite (Fe3O4) particles, were observed. Relatively large magnetite particles (ca. 30 nm or more), capable of retaining a remanent magnetisation at room temperature, were found in the abdomens, but were absent in the heads and thoraxes. In both samples, more than 98% of the iron atoms were due to ferritin.

Am5-HT7: molecular and pharmacological characterization of the first serotonin receptor of the honeybee (Apis mellifera).

PubMed

Schlenstedt, Jana; Balfanz, Sabine; Baumann, Arnd; Blenau, Wolfgang

2006-09-01

The biogenic amine serotonin (5-HT) plays a key role in the regulation and modulation of many physiological and behavioural processes in both vertebrates and invertebrates. These functions are mediated through the binding of serotonin to its receptors, of which 13 subtypes have been characterized in vertebrates. We have isolated a cDNA from the honeybee Apis mellifera (Am5-ht7) sharing high similarity to members of the 5-HT(7) receptor family. Expression of the Am5-HT(7) receptor in HEK293 cells results in an increase in basal cAMP levels, suggesting that Am5-HT(7) is expressed as a constitutively active receptor. Serotonin application to Am5-ht7-transfected cells elevates cyclic adenosine 3',5'-monophosphate (cAMP) levels in a dose-dependent manner (EC(50) = 1.1-1.8 nm). The Am5-HT(7) receptor is also activated by 5-carboxamidotryptamine, whereas methiothepin acts as an inverse agonist. Receptor expression has been investigated by RT-PCR, in situ hybridization, and western blotting experiments. Receptor mRNA is expressed in the perikarya of various brain neuropils, including intrinsic mushroom body neurons, and in peripheral organs. This study marks the first comprehensive characterization of a serotonin receptor in the honeybee and should facilitate further analysis of the role(s) of the receptor in mediating the various central and peripheral effects of 5-HT.

Comparison of the energetic stress associated with experimental Nosema ceranae and Nosema apis infection of honeybees (Apis mellifera).

PubMed

Martín-Hernández, Raquel; Botías, Cristina; Barrios, Laura; Martínez-Salvador, Amparo; Meana, Aránzazu; Mayack, Christopher; Higes, Mariano

2011-09-01

Nosema ceranae is a relatively new and widespread parasite of the western honeybee Apis mellifera that provokes a new form of nosemosis. In comparison to Nosema apis, which has been infecting the honeybee for much longer, N. ceranae seems to have co-evolved less with this host, causing a more virulent disease. Given that N. apis and N. ceranae are obligate intracellular microsporidian parasites, needing host energy to reproduce, energetic stress may be an important factor contributing to the increased virulence observed. Through feeding experiments on caged bees, we show that both mortality and sugar syrup consumption were higher in N. ceranae-infected bees than in N. apis-infected and control bees. The mortality and sugar syrup consumption are also higher in N. apis-infected bees than in controls, but are less than in N. ceranae-infected bees. With both microsporidia, mortality and sugar syrup consumption increased in function of the increasing spore counts administered for infection. The differences in energetic requirements between both Nosema spp. confirm that their metabolic patterns are not the same, which may depend critically on host-parasite interactions and, ultimately, on host pathology. The repercussions of this increased energetic stress may even explain the changes in host behavior due to starvation, lack of thermoregulatory capacity, or higher rates of trophallaxis, which might enhance transmission and bee death.

Honeybees (Apis mellifera) as a biological barrier for contamination of honey by environmental toxic metals.

PubMed

Dżugan, Małgorzata; Wesołowska, Monika; Zaguła, Grzegorz; Kaczmarski, Mateusz; Czernicka, Maria; Puchalski, Czesław

2018-01-27

The aim of the study was to investigate the transfer of toxic metals from honeybee workers (Apis mellifera L.) to bee honey in relation to the ecological state of the environment. The materials of the study consisted of samples of honeybee bodies and varietal honeys taken from the same apiary located in three areas: R1-urbanized (16), R2-ecologically clean (16) and R3-industrialized (15) of south-eastern Poland. The contents of 14 elements in all tested samples, including toxic metals (Cd, Pb, Hg, Al, Ni, Tl) as well as bioelements (K, Mg, Ca, Mn, Fe, Zn, Cu, Se), were analysed by the ICP-OES method with prior microwave mineralization. The concentrations of the majority of the studied elements, excluding aluminum and lead, were significantly higher in bee bodies than in honey samples (P < 0.05). The pollution of bee bodies by toxic metals was dependent on the environmental cleanliness, and the most pollution was observed in the industrialized area. The bee body was the most effective barrier for Cd and Tl transfer to the honey, while the level of Ni was similar in both tested materials. The Al concentration was significantly higher in honey than bee bodies (14.81 ± 24.69 and 6.51 ± 5.83 mg kg -1 , respectively), which suggests the possibility of secondary contamination of honey. The greatest sensitivity to heavy metal pollution was observed in honeydew honey compared to nectar honeys (P < 0.05). It was proved for the first time that bees work as biofilters for toxic metals and prevent honey contamination.

MicroRNA signatures characterizing caste-independent ovarian activity in queen and worker honeybees (Apis mellifera L.).

PubMed

Macedo, L M F; Nunes, F M F; Freitas, F C P; Pires, C V; Tanaka, E D; Martins, J R; Piulachs, M-D; Cristino, A S; Pinheiro, D G; Simões, Z L P

2016-06-01

Queen and worker honeybees differ profoundly in reproductive capacity. The queen of this complex society, with 200 highly active ovarioles in each ovary, is the fertile caste, whereas the workers have approximately 20 ovarioles as a result of receiving a different diet during larval development. In a regular queenright colony, the workers have inactive ovaries and do not reproduce. However, if the queen is sensed to be absent, some of the workers activate their ovaries, producing viable haploid eggs that develop into males. Here, a deep-sequenced ovary transcriptome library of reproductive workers was used as supporting data to assess the dynamic expression of the regulatory molecules and microRNAs (miRNAs) of reproductive and nonreproductive honeybee females. In this library, most of the differentially expressed miRNAs are related to ovary physiology or oogenesis. When we quantified the dynamic expression of 19 miRNAs in the active and inactive worker ovaries and compared their expression in the ovaries of virgin and mated queens, we noted that some miRNAs (miR-1, miR-31a, miR-13b, miR-125, let-7 RNA, miR-100, miR-276, miR-12, miR-263a, miR-306, miR-317, miR-92a and miR-9a) could be used to identify reproductive and nonreproductive statuses independent of caste. Furthermore, integrative gene networks suggested that some candidate miRNAs function in the process of ovary activation in worker bees. © 2016 The Royal Entomological Society.

Using an abstract geometry in virtual reality to explore choice behaviour: visual flicker preferences in honeybees.

PubMed

Van De Poll, Matthew N; Zajaczkowski, Esmi L; Taylor, Gavin J; Srinivasan, Mandyam V; van Swinderen, Bruno

2015-11-01

Closed-loop paradigms provide an effective approach for studying visual choice behaviour and attention in small animals. Different flying and walking paradigms have been developed to investigate behavioural and neuronal responses to competing stimuli in insects such as bees and flies. However, the variety of stimulus choices that can be presented over one experiment is often limited. Current choice paradigms are mostly constrained as single binary choice scenarios that are influenced by the linear structure of classical conditioning paradigms. Here, we present a novel behavioural choice paradigm that allows animals to explore a closed geometry of interconnected binary choices by repeatedly selecting among competing objects, thereby revealing stimulus preferences in an historical context. We used our novel paradigm to investigate visual flicker preferences in honeybees (Apis mellifera) and found significant preferences for 20-25 Hz flicker and avoidance of higher (50-100 Hz) and lower (2-4 Hz) flicker frequencies. Similar results were found when bees were presented with three simultaneous choices instead of two, and when they were given the chance to select previously rejected choices. Our results show that honeybees can discriminate among different flicker frequencies and that their visual preferences are persistent even under different experimental conditions. Interestingly, avoided stimuli were more attractive if they were novel, suggesting that novelty salience can override innate preferences. Our recursive virtual reality environment provides a new approach to studying visual discrimination and choice behaviour in animals. © 2015. Published by The Company of Biologists Ltd.

Anti-fibrinolytic and anti-microbial activities of a serine protease inhibitor from honeybee (Apis cerana) venom.

PubMed

Yang, Jie; Lee, Kwang Sik; Kim, Bo Yeon; Choi, Yong Soo; Yoon, Hyung Joo; Jia, Jingming; Jin, Byung Rae

2017-10-01

Bee venom contains a variety of peptide constituents, including low-molecular-weight protease inhibitors. While the putative low-molecular-weight serine protease inhibitor Api m 6 containing a trypsin inhibitor-like cysteine-rich domain was identified from honeybee (Apis mellifera) venom, no anti-fibrinolytic or anti-microbial roles for this inhibitor have been elucidated. In this study, we identified an Asiatic honeybee (A. cerana) venom serine protease inhibitor (AcVSPI) that was shown to act as a microbial serine protease inhibitor and plasmin inhibitor. AcVSPI was found to consist of a trypsin inhibitor-like domain that displays ten cysteine residues. Interestingly, the AcVSPI peptide sequence exhibited high similarity to the putative low-molecular-weight serine protease inhibitor Api m 6, which suggests that AcVSPI is an allergen Api m 6-like peptide. Recombinant AcVSPI was expressed in baculovirus-infected insect cells, and it demonstrated inhibitory activity against trypsin, but not chymotrypsin. Additionally, AcVSPI has inhibitory effects against plasmin and microbial serine proteases; however, it does not have any detectable inhibitory effects on thrombin or elastase. Consistent with these inhibitory effects, AcVSPI inhibited the plasmin-mediated degradation of fibrin to fibrin degradation products. AcVSPI also bound to bacterial and fungal surfaces and exhibited anti-microbial activity against fungi as well as gram-positive and gram-negative bacteria. These findings demonstrate the anti-fibrinolytic and anti-microbial roles of AcVSPI as a serine protease inhibitor. Copyright © 2017 Elsevier Inc. All rights reserved.

Relatedness among honeybees (Apis mellifera) of a drone congregation

PubMed Central

Baudry, E.; Solignac, M.; Garnery, L.; Gries, M.; Cornuet, J.-M.; Koeniger, N.

1998-01-01

The honeybee (Apis mellifera) queen mates during nuptial flights, in the so-called drone congregation area where many males from surrounding colonies gather. Using 20 highly polymorphic microsatellite loci, we studied a sample of 142 drones captured in a congregation close to Oberursel (Germany). A parentage test based on lod score showed that this sample contained one group of four brothers, six groups of three brothers, 20 groups of two brothers and 80 singletons. These values are very close to a Poisson distribution. Therefore, colonies were apparently equally represented in the drone congregation, and calculations showed that the congregation comprised males that originated from about 240 different colonies. This figure is surprisingly high. Considering the density of colonies around the congregation area and the average flight range of males, it suggests that most colonies within the recruitment perimeter delegated drones to the congregation with an equal probability, resulting in an almost perfect panmixis. Consequently, the relatedness between a queen and her mates, and hence the inbreeding coefficient of the progeny, should be minimized. The relatedness among the drones mated to the same queen is also very low, maximizing the genetic diversity among the different patrilines of a colony.

Rapid learning dynamics in individual honeybees during classical conditioning.

PubMed

Pamir, Evren; Szyszka, Paul; Scheiner, Ricarda; Nawrot, Martin P

2014-01-01

Associative learning in insects has been studied extensively by a multitude of classical conditioning protocols. However, so far little emphasis has been put on the dynamics of learning in individuals. The honeybee is a well-established animal model for learning and memory. We here studied associative learning as expressed in individual behavior based on a large collection of data on olfactory classical conditioning (25 datasets, 3298 animals). We show that the group-averaged learning curve and memory retention score confound three attributes of individual learning: the ability or inability to learn a given task, the generally fast acquisition of a conditioned response (CR) in learners, and the high stability of the CR during consecutive training and memory retention trials. We reassessed the prevailing view that more training results in better memory performance and found that 24 h memory retention can be indistinguishable after single-trial and multiple-trial conditioning in individuals. We explain how inter-individual differences in learning can be accommodated within the Rescorla-Wagner theory of associative learning. In both data-analysis and modeling we demonstrate how the conflict between population-level and single-animal perspectives on learning and memory can be disentangled.

Rapid learning dynamics in individual honeybees during classical conditioning

PubMed Central

Pamir, Evren; Szyszka, Paul; Scheiner, Ricarda; Nawrot, Martin P.

2014-01-01

Associative learning in insects has been studied extensively by a multitude of classical conditioning protocols. However, so far little emphasis has been put on the dynamics of learning in individuals. The honeybee is a well-established animal model for learning and memory. We here studied associative learning as expressed in individual behavior based on a large collection of data on olfactory classical conditioning (25 datasets, 3298 animals). We show that the group-averaged learning curve and memory retention score confound three attributes of individual learning: the ability or inability to learn a given task, the generally fast acquisition of a conditioned response (CR) in learners, and the high stability of the CR during consecutive training and memory retention trials. We reassessed the prevailing view that more training results in better memory performance and found that 24 h memory retention can be indistinguishable after single-trial and multiple-trial conditioning in individuals. We explain how inter-individual differences in learning can be accommodated within the Rescorla–Wagner theory of associative learning. In both data-analysis and modeling we demonstrate how the conflict between population-level and single-animal perspectives on learning and memory can be disentangled. PMID:25309366

Proteome Analysis Unravels Mechanism Underling the Embryogenesis of the Honeybee Drone and Its Divergence with the Worker (Apis mellifera lingustica).

PubMed

Fang, Yu; Feng, Mao; Han, Bin; Qi, Yuping; Hu, Han; Fan, Pei; Huo, Xinmei; Meng, Lifeng; Li, Jianke

2015-09-04

The worker and drone bees each contain a separate diploid and haploid genetic makeup, respectively. Mechanisms regulating the embryogenesis of the drone and its mechanistic difference with the worker are still poorly understood. The proteomes of the two embryos at three time-points throughout development were analyzed by applying mass spectrometry-based proteomics. We identified 2788 and 2840 proteins in the worker and drone embryos, respectively. The age-dependent proteome driving the drone embryogenesis generally follows the worker's. The two embryos however evolve a distinct proteome setting to prime their respective embryogenesis. The strongly expressed proteins and pathways related to transcriptional-translational machinery and morphogenesis at 24 h drone embryo relative to the worker, illustrating the earlier occurrence of morphogenesis in the drone than worker. These morphogenesis differences remain through to the middle-late stage in the two embryos. The two embryos employ distinct antioxidant mechanisms coinciding with the temporal-difference organogenesis. The drone embryo's strongly expressed cytoskeletal proteins signify key roles to match its large body size. The RNAi induced knockdown of the ribosomal protein offers evidence for the functional investigation of gene regulating of honeybee embryogenesis. The data significantly expand novel regulatory mechanisms governing the embryogenesis, which is potentially important for honeybee and other insects.

Contribution of honeybee drones of different age to colonial thermoregulation*

PubMed Central

Kovac, Helmut; Stabentheiner, Anton; Brodschneider, Robert

2011-01-01

In addition to honeybee workers, drones also contribute to colonial thermoregulation. We show the drones’ contribution to thermoregulation at 5 different experimental temperatures ranging from 15–34 °C. The frequency and the degree of endothermy depended on the drones’ local ambient temperature and age. Location on brood or non-brood areas had no influence. The frequency of endothermic drones and the intensity of endothermy increased with decreasing temperature. 30% of drones of 8 days and older heated their thorax by more than 1 °C above the abdomen. The youngest drones (0–2 days) did not exceed this level of endothermy. Though young drones were less often engaged in active heat production, their contribution to brood warming was not insignificant because their abundance on the brood nest was 3.5 times higher than that of the oldest drones (≥13 days). Results suggest that the stimulus for the drones’ increased frequency of heating at low experimental temperatures was their low local ambient air and/or comb temperature. PMID:22140282

Contribution of honeybee drones of different age to colonial thermoregulation.

PubMed

Kovac, Helmut; Stabentheiner, Anton; Brodschneider, Robert

2009-01-01

In addition to honeybee workers, drones also contribute to colonial thermoregulation. We show the drones' contribution to thermoregulation at 5 different experimental temperatures ranging from 15-34 °C. The frequency and the degree of endothermy depended on the drones' local ambient temperature and age. Location on brood or non-brood areas had no influence. The frequency of endothermic drones and the intensity of endothermy increased with decreasing temperature. 30% of drones of 8 days and older heated their thorax by more than 1 °C above the abdomen. The youngest drones (0-2 days) did not exceed this level of endothermy. Though young drones were less often engaged in active heat production, their contribution to brood warming was not insignificant because their abundance on the brood nest was 3.5 times higher than that of the oldest drones (≥13 days). Results suggest that the stimulus for the drones' increased frequency of heating at low experimental temperatures was their low local ambient air and/or comb temperature.

`Special agents' trigger social waves in giant honeybees ( Apis dorsata)

NASA Astrophysics Data System (ADS)

Schmelzer, Evelyn; Kastberger, Gerald

2009-12-01

Giant honeybees ( Apis dorsata) nest in the open and have therefore evolved a variety of defence strategies. Against predatory wasps, they produce highly coordinated Mexican wavelike cascades termed ‘shimmering’, whereby hundreds of bees flip their abdomens upwards. Although it is well known that shimmering commences at distinct spots on the nest surface, it is still unclear how shimmering is generated. In this study, colonies were exposed to living tethered wasps that were moved in front of the experimental nest. Temporal and spatial patterns of shimmering were investigated in and after the presence of the wasp. The numbers and locations of bees that participated in the shimmering were assessed, and those bees that triggered the waves were identified. The findings reveal that the position of identified trigger cohorts did not reflect the experimental path of the tethered wasp. Instead, the trigger centres were primarily arranged in the close periphery of the mouth zone of the nest, around those parts where the main locomotory activity occurs. This favours the ‘special-agents’ hypothesis that suggest that groups of specialized bees initiate the shimmering.

A PCR detection method for rapid identification of Melissococcus pluton in honeybee larvae.

PubMed

Govan, V A; Brözel, V; Allsopp, M H; Davison, S

1998-05-01

Melissococcus pluton is the causative agent of European foulbrood, a disease of honeybee larvae. This bacterium is particularly difficult to isolate because of its stringent growth requirements and competition from other bacteria. PCR was used selectively to amplify specific rRNA gene sequences of M. pluton from pure culture, from crude cell lysates, and directly from infected bee larvae. The PCR primers were designed from M. pluton 16S rRNA sequence data. The PCR products were visualized by agarose gel electrophoresis and confirmed as originating from M. pluton by sequencing in both directions. Detection was highly specific, and the probes did not hybridize with DNA from other bacterial species tested. This method enabled the rapid and specific detection and identification of M. pluton from pure cultures and infected bee larvae.

A PCR Detection Method for Rapid Identification of Melissococcus pluton in Honeybee Larvae

PubMed Central

Govan, V. A.; Brözel, V.; Allsopp, M. H.; Davison, S.

1998-01-01

Melissococcus pluton is the causative agent of European foulbrood, a disease of honeybee larvae. This bacterium is particularly difficult to isolate because of its stringent growth requirements and competition from other bacteria. PCR was used selectively to amplify specific rRNA gene sequences of M. pluton from pure culture, from crude cell lysates, and directly from infected bee larvae. The PCR primers were designed from M. pluton 16S rRNA sequence data. The PCR products were visualized by agarose gel electrophoresis and confirmed as originating from M. pluton by sequencing in both directions. Detection was highly specific, and the probes did not hybridize with DNA from other bacterial species tested. This method enabled the rapid and specific detection and identification of M. pluton from pure cultures and infected bee larvae. PMID:9572987

7 CFR 322.6 - Export certificate.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.6 Export certificate. Each shipment of bees and honeybee germ plasm arriving in the United States from an approved...

7 CFR 322.5 - General requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.5 General requirements. (a) All shipments of bees and honeybee germ plasm imported into the United States under this...

7 CFR 322.4 - Approved regions.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.4 Approved regions..., Bermuda, Canada, France, Great Britain, New Zealand, and Sweden. (c) Bees other than honeybees. The...

7 CFR 322.6 - Export certificate.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.6 Export certificate. Each shipment of bees and honeybee germ plasm arriving in the United States from an approved...

7 CFR 322.6 - Export certificate.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.6 Export certificate. Each shipment of bees and honeybee germ plasm arriving in the United States from an approved...

7 CFR 322.5 - General requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.5 General requirements. (a) All shipments of bees and honeybee germ plasm imported into the United States under this...

7 CFR 322.4 - Approved regions.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.4 Approved regions..., Bermuda, Canada, France, Great Britain, New Zealand, and Sweden. (c) Bees other than honeybees. The...

7 CFR 322.5 - General requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.5 General requirements. (a) All shipments of bees and honeybee germ plasm imported into the United States under this...

7 CFR 322.5 - General requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.5 General requirements. (a) All shipments of bees and honeybee germ plasm imported into the United States under this...

7 CFR 322.4 - Approved regions.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.4 Approved regions..., Bermuda, Canada, France, Great Britain, New Zealand, and Sweden. (c) Bees other than honeybees. The...

7 CFR 322.6 - Export certificate.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.6 Export certificate. Each shipment of bees and honeybee germ plasm arriving in the United States from an approved...

7 CFR 322.5 - General requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.5 General requirements. (a) All shipments of bees and honeybee germ plasm imported into the United States under this...

7 CFR 322.4 - Approved regions.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.4 Approved regions..., Bermuda, Canada, France, Great Britain, New Zealand, and Sweden. (c) Bees other than honeybees. The...

7 CFR 322.4 - Approved regions.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation of Adult Honeybees, Honeybee Germ Plasm, and Bees Other Than Honeybees From Approved Regions § 322.4 Approved regions..., Bermuda, Canada, France, Great Britain, New Zealand, and Sweden. (c) Bees other than honeybees. The...

Imidacloprid intensifies its impact on honeybee and bumblebee cellular immune response when challenged with LPS (lippopolysacharide) of Escherichia coli.

PubMed

Walderdorff, Louise; Laval-Gilly, Philippe; Bonnefoy, Antoine; Falla-Angel, Jaïro

2018-07-01

Insect hemocytes play an important role in insects' defense against environmental stressors as they are entirely dependent on their innate immune system for pathogen defense. In recent years a dramatic decline of pollinators has been reported in many countries. The drivers of this declines appear to be associated with pathogen infections like viruses, bacteria or fungi in combination with pesticide exposure. The aim of this study was thus to investigate the impact of imidacloprid, a neonicotinoid insecticide, on the cellular immune response of two pollinators (Apis mellifera and Bombus terrestris) during simultaneous immune activation with LPS (lipopolysaccharide) of Escherichia coli. For this purpose the phagocytosis capacity as well as the production of H 2 O 2 and NO of larval hemocytes, exposed to five different imidacloprid concentrations in vitro, was measured. All used pesticide concentrations showed a weakening effect on phagocytosis with but also without LPS activation. Imidacloprid decreased H 2 O 2 and increased NO production in honeybees. Immune activation by LPS clearly reinforced the effect of imidacloprid on the immune response of hemocytes in all three immune parameters tested. Bumblebee hemocytes appeared more sensitive to imidacloprid during phagocytosis assays while imidacloprid showed a greater impact on honeybee hemocytes during H 2 O 2 and NO production. Copyright © 2018 Elsevier Ltd. All rights reserved.

A scientific note on the lactic acid bacterial flora within the honeybee subspecies Apis mellifera (Buckfast), A.m. scutellata, A.m. mellifera, and A.m. monticola

USDA-ARS?s Scientific Manuscript database

It was discovered by Olofsson and Vásquez (2008) that a novel lactic acid bacteria (LAB) microbiota with numerous LAB, comprising the genera Lactobacillus and Bifidobacterium, live in a symbiotic relationship with honeybees (Apis mellifera) in their honey stomach. Previous results from 16S rRNA gene...

Colony impact of pesticide-induced sublethal effects on honeybee workers: A simulation study using BEEHAVE.

PubMed

Thorbek, Pernille; Campbell, Peter J; Thompson, Helen M

2017-03-01

Research on neonicotinoids and honeybees have changed focus from direct mortality to sublethal effects. In the present study, a published honeybee model, BEEHAVE, is used to compare induced colony level impact of pesticides including direct mortality, poor brood care, disorientation, and increased handling time in oilseed rape and sunflower crops. Actual effects on individual bees will depend on exposure concentrations, but in the present study large effects were enforced. In oilseed rape, poor brood care had the largest colony impact, because it created a bottleneck for spring build-up of the workforce, and colony impact for all effect types peaked 1 mo after exposure ceased. In sunflower, the later exposure changed the response so colony impact peaked during exposure, and the bottleneck was honey store build-up. In all scenarios, good forage mitigated effects substantially. It is concluded that field studies should continue at least 1 mo after exposure to ensure detection of ecologically relevant sublethal effects. The results indicated that even if a sublethal effect is difficult to detect in the field, subsequent ecologically relevant colony level impacts would be clear if studies are continued for 1 mo after exposure. Guidance for regulatory studies recommends extended observation periods, and published field studies already use extended observation periods, so it is concluded that current methods are adequate for detecting ecologically relevant sublethal effects. Although published laboratory and semifield studies conducted under controlled exposure conditions suggest that sublethal effects may occur, published field studies with neonicotinoid seed treatments, naturally foraging bees, and extended observation periods do not report colony-level effects, suggesting that in these studies no ecologically relevant sublethal effects occurred. Environ Toxicol Chem 2017;36:831-840. © 2016 SETAC. © 2016 SETAC.

[Binding of tylosin, tilmicosin and oxytetracycline to proteins from honeybees, larvae and beehive products].

PubMed

Reynaldi, F J; Lacunza, J; Alippi, A M; Rule, R

2010-01-01

American Foulbrood (AFB) caused by the spore-forming bacterium Paenibacillus larvae is the most serious disease of bacterial origin affecting larvae and pupae of honeybees. Antibiotics are used in many countries for the control of AFB in high incidence areas, but their misuse may lead to antibiotic resistance of bacterial strains and honey contamination. The objective of the present work was to determine, through a biological method, the protein binding of tylosin, tilmicosin and oxytetracycline to worker jelly; honey; pollen; adult bees and larvae in order to propose their kinetic routes. The sensitivity limit of the technique used was 0.05 μg/ml for tylosin and tilmicosin and 0.01 μg/ml for oxytetracycline, respectively. The method had intra and inter-assay correlation coefficients over 0.90, respectively and a coefficient variation of intra-and inter-assay for all antibiotics and processed samples under 5%. Tylosin and oxytetracycline presented lower percentages of protein binding in tissues and hive products (average 15%) in relation to those observed for tilmicosin (29%). In conclusion, tylosin is useful for AFB control in honey bee colonies due to its chemical characteristics, antimicrobial activity and levels of protein binding in bees, larvae, and beehive products.

Method for training honeybees to respond to olfactory stimuli and enhancement of memory retention therein

DOEpatents

McCade, Kirsten J.; Wingo, Robert M.; Haarmann, Timothy K.; Sutherland, Andrew; Gubler, Walter D.

2015-12-15

A specialized conditioning protocol for honeybees that is designed for use within a complex agricultural ecosystem. This method ensures that the conditioned bees will be less likely to exhibit a conditioned response to uninfected plants, a false positive response that would render such a biological sensor unreliable for agricultural decision support. Also described is a superboosting training regime that allows training without the aid of expensive equipment and protocols for training in out in the field. Also described is a memory enhancing cocktail that aids in long term memory retention of a vapor signature. This allows the bees to be used in the field for longer durations and with fewer bees trained overall.

High sample throughput genotyping for estimating C-lineage introgression in the dark honeybee: an accurate and cost-effective SNP-based tool.

PubMed

Henriques, Dora; Browne, Keith A; Barnett, Mark W; Parejo, Melanie; Kryger, Per; Freeman, Tom C; Muñoz, Irene; Garnery, Lionel; Highet, Fiona; Jonhston, J Spencer; McCormack, Grace P; Pinto, M Alice

2018-06-04

The natural distribution of the honeybee (Apis mellifera L.) has been changed by humans in recent decades to such an extent that the formerly widest-spread European subspecies, Apis mellifera mellifera, is threatened by extinction through introgression from highly divergent commercial strains in large tracts of its range. Conservation efforts for A. m. mellifera are underway in multiple European countries requiring reliable and cost-efficient molecular tools to identify purebred colonies. Here, we developed four ancestry-informative SNP assays for high sample throughput genotyping using the iPLEX Mass Array system. Our customized assays were tested on DNA from individual and pooled, haploid and diploid honeybee samples extracted from different tissues using a diverse range of protocols. The assays had a high genotyping success rate and yielded accurate genotypes. Performance assessed against whole-genome data showed that individual assays behaved well, although the most accurate introgression estimates were obtained for the four assays combined (117 SNPs). The best compromise between accuracy and genotyping costs was achieved when combining two assays (62 SNPs). We provide a ready-to-use cost-effective tool for accurate molecular identification and estimation of introgression levels to more effectively monitor and manage A. m. mellifera conservatories.

Honeybee Retinal Glial Cells Transform Glucose and Supply the Neurons with Metabolic Substrate

NASA Astrophysics Data System (ADS)

Tsacopoulos, M.; Evequoz-Mercier, V.; Perrottet, P.; Buchner, E.

1988-11-01

The retina of the honeybee drone is a nervous tissue in which glial cells and photoreceptor cells (sensory neurons) constitute two distinct metabolic compartments. Retinal slices incubated with 2-deoxy[3H]glucose convert this glucose analogue to 2-deoxy[3H]glucose 6-phosphate, but this conversion is made only in the glial cells. Hence, glycolysis occurs only in glial cells. In contrast, the neurons consume O2 and this consumption is sustained by the hydrolysis of glycogen, which is contained in large amounts in the glia. During photostimulation the increased oxidative metabolism of the neurons is sustained by a higher supply of carbohydrates from the glia. This clear case of metabolic interaction between neurons and glial cells supports Golgi's original hypothesis, proposed nearly 100 years ago, about the nutritive function of glial cells in the nervous system.

Pollen dispersal of tropical trees (Dinizia excelsa: Fabaceae) by native insects and African honeybees in pristine and fragmented Amazonian rainforest.

PubMed

Dick, Christopher W; Etchelecu, Gabriela; Austerlitz, Frédéric

2003-03-01

Tropical rainforest trees typically occur in low population densities and rely on animals for cross-pollination. It is of conservation interest therefore to understand how rainforest fragmentation may alter the pollination and breeding structure of remnant trees. Previous studies of the Amazonian tree Dinizia excelsa (Fabaceae) found African honeybees (Apis mellifera scutellata) as the predominant pollinators of trees in highly disturbed habitats, transporting pollen up to 3.2 km between pasture trees. Here, using microsatellite genotypes of seed arrays, we compare outcrossing rates and pollen dispersal distances of (i) remnant D. excelsa in three large ranches, and (ii) a population in undisturbed forest in which African honeybees were absent. Self-fertilization was more frequent in the disturbed habitats (14%, n = 277 seeds from 12 mothers) than in undisturbed forest (10%, n = 295 seeds from 13 mothers). Pollen dispersal was extensive in all three ranches compared to undisturbed forest, however. Using a twogener analysis, we estimated a mean pollen dispersal distance of 1509 m in Colosso ranch, assuming an exponential dispersal function, and 212 m in undisturbed forest. The low effective density of D. excelsa in undisturbed forest (approximately 0.1 trees/ha) indicates that large areas of rainforest must be preserved to maintain minimum viable populations. Our results also suggest, however, that in highly disturbed habitats Apis mellifera may expand genetic neighbourhood areas, thereby linking fragmented and continuous forest populations.