Hey! A Scorpion Stung Me!

MedlinePlus

... arachnid family, which also includes mites, ticks , and spiders. Scorpions are about 3 inches long (about the ... A Bee Stung Me! Hey! A Black Widow Spider Bit Me! Hey! A Mosquito Bit Me! Hey! ...

In vitro and in vivo evaluation of cypermethrin, amitraz, and piperonyl butoxide mixtures for the control of resistant Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) in the Mexican tropics

USDA-ARS?s Scientific Manuscript database

The southern cattle fever tick, Rhipicephalus (Boophilus) microplus (Canestrini), is a haematophagous arachnid (Acari: Ixodidae) recognized globally as an economically important ectoparasite of cattle in tropical and subtropical agroecosystems. Populations of this invasive tick species around the wo...

Amplitude distributions of the spider heartpulse in response to gravitational stimuli

NASA Technical Reports Server (NTRS)

Finck, A.

1984-01-01

The arachnid Nuctenea sclopetaria (Clerck) which possesses a neurogenic heart, measuring the heartbeat is under efferent control through a dorsal nerve arising from a brain center is discussed. It was shown that the heartrate of this spider is also modulated by an afferent input associated with small increments of gravity. A compressive force on the order of 40 micron is sufficient to elicit a threshold change in heart rate for a typical (100mg) spider. This obtains in a hyper-Gz field less than 1.001. The functional relationship between gravity and heartrate is logarithmic between the absolute threshold and at least 1.5 Gz. A model was proposed in which equilibrium and movement are maintained by changes in blood pressure. It is concluded that the arachnid equilibrium system is like a weight detector which employs a hydraulic compensatory mechanism.

Molecular phylogeny of Entomophthoromycota

USDA-ARS?s Scientific Manuscript database

The Entomophthoromycota is a ubiquitous group of fungi best known as pathogens of a wide variety of economically important insect pests, arachnids, and other soil invertebrates, a smaller number of parasites of reptiles, vertebrates (including humans), macromycetes, fern gametophytes, and desmid alg...

Sulfakinin is an important regulator of digestive processes in the migratory locust, Locusta migratoria

USDA-ARS?s Scientific Manuscript database

Sulfakinin (SK) is a sulfated insect neuropeptide that is best known for its function as a satiety factor. It displays structural and functional similarities with the vertebrate peptides gastrin and cholecystokinin. Peptidomic studies in multiple insects, crustaceans and arachnids have revealed th...

All about Bugs. Animal Life for Children. [Videotape].

ERIC Educational Resources Information Center

2000

Bugs fascinate children, and each kind of bug plays a special role in the circle of life. Some bugs pollinate plants, while others help to decompose plant and animal waste. In this videotape, students learn about the similar characteristics that all bugs share and compare them to their close cousins, the arachnids. This videotape correlates to the…

Arachnid aloft: directed aerial descent in neotropical canopy spiders.

PubMed

Yanoviak, Stephen P; Munk, Yonatan; Dudley, Robert

2015-09-06

The behaviour of directed aerial descent has been described for numerous taxa of wingless hexapods as they fall from the tropical rainforest canopy, but is not known in other terrestrial arthropods. Here, we describe similar controlled aerial behaviours for large arboreal spiders in the genus Selenops (Selenopidae). We dropped 59 such spiders from either canopy platforms or tree crowns in Panama and Peru; the majority (93%) directed their aerial trajectories towards and then landed upon nearby tree trunks. Following initial dorsoventral righting when necessary, falling spiders oriented themselves and then translated head-first towards targets; directional changes were correlated with bilaterally asymmetric motions of the anterolaterally extended forelegs. Aerial performance (i.e. the glide index) decreased with increasing body mass and wing loading, but not with projected surface area of the spider. Along with the occurrence of directed aerial descent in ants, jumping bristletails, and other wingless hexapods, this discovery of targeted gliding in selenopid spiders further indicates strong selective pressures against uncontrolled falls into the understory for arboreal taxa. © 2015 The Author(s).

Forest refugia in Western and Central Africa as 'museums' of Mesozoic biodiversity.

PubMed

Murienne, Jérôme; Benavides, Ligia R; Prendini, Lorenzo; Hormiga, Gustavo; Giribet, Gonzalo

2013-02-23

The refugial speciation model, or 'species pump', is widely accepted in the context of tropical biogeography and has been advocated as an explanation for present species distributions in tropical Western and Central Africa. In order to test this hypothesis, a phylogeny of the cryptic arachnid order Ricinulei, based on four nuclear and mitochondrial DNA markers, was inferred. This ancient clade of litter-dwelling arthropods, endemic to the primary forests of Western and Central Africa and the Neotropics, might provide insights into the mode and tempo of evolution in Africa. Twenty-six African ricinuleid specimens were sampled from eight countries spanning the distribution of Ricinulei on the continent, and analysed together with Neotropical samples plus other arachnid outgroups. The phylogenetic and molecular dating results suggest that Ricinulei diversified in association with the fragmentation of Gondwana. The early diversification of Ricinoides in Western and Central Africa around 88 (±33) Ma fits old palaeogeographical events better than recent climatic fluctuations. Unlike most recent molecular studies, these results agree with fossil evidence, suggesting that refugia may have acted as 'museums' conserving ancient diversity rather than as engines generating diversity during successive episodes of climatic fluctuation in Africa.

Vertical T-maze Choice Assay for Arthropod Response to Odorants

PubMed Central

Stelinski, Lukasz; Tiwari, Siddharth

2013-01-01

Given the economic importance of insects and arachnids as pests of agricultural crops, urban environments or as vectors of plant and human diseases, various technologies are being developed as control tools. A subset of these tools focuses on modifying the behavior of arthropods by attraction or repulsion. Therefore, arthropods are often the focus of behavioral investigations. Various tools have been developed to measure arthropod behavior, including wind tunnels, flight mills, servospheres, and various types of olfactometers. The purpose of these tools is to measure insect or arachnid response to visual or more often olfactory cues. The vertical T-maze oflactometer described here measures choices performed by insects in response to attractants or repellents. It is a high throughput assay device that takes advantage of the positive phototaxis (attraction to light) and negative geotaxis (tendency to walk or fly upward) exhibited by many arthropods. The olfactometer consists of a 30 cm glass tube that is divided in half with a Teflon strip forming a T-maze. Each half serves as an arm of the olfactometer enabling the test subjects to make a choice between two potential odor fields in assays involving attractants. In assays involving repellents, lack of normal response to known attractants can also be measured as a third variable. PMID:23439130

Human Permanent Ectoparasites; Recent Advances on Biology and Clinical Significance of Demodex Mites: Narrative Review Article.

PubMed

Litwin, Dorota; Chen, WenChieh; Dzika, Ewa; Korycińska, Joanna

2017-01-01

Demodex is a genus of mites living predominantly in mammalian pilosebaceous units. They are commonly detected in the skin of face, with increasing numbers in inflammatory lesions. Causation between Demodex mites and inflammatory diseases, such as rosacea, blepharitis, perioral and seborrhoeic dermatitis or chalazion, is controversially discussed. Clinical observations indicate a primary form of human Demodex infection. The aim of this review was to highlight the biological aspects of Demodex infestation and point out directions for the future research. We conducted a broad review based on the electronic database sources such as MEDLINE, PubMed and Scopus with regard to the characteristics of the Demodex species, methods of examination and worldwide epidemiology, molecular studies and its role in the complex human ecosystem. Demodex mites are organisms with a worldwide importance as they act in indicating several dermatoses, under certain conditions. However, correlations between Demodex and other parasites or microorganisms occupying one host, as well as interactions between these arachnids and its symbiotic bacteria should be considered. There are few methods of human mites' examination depending on purpose of the study. Nevertheless, paying attention must be needed as polymorphism of Demodex species has been reported. Overall, the present review will focus on different aspects of Demodex mites' biology and significance of these arachnids in human's health.

Fifty years of entomological publications in the Revista de Biología Tropical.

PubMed

Hanson, Paul

2002-01-01

Over its fifty year history nearly twenty percent of the papers published in the Revista de Biología Tropical have been about insects and arachnids. In the 1950's papers on arthropods of medical importance were dominant, in the 1960's there was a poliferation of papers on bees, and in more recent years the subjects have become increasingly diverse. In terms of nationality of contributing authors, the journal appears to have become increasingly international in later years.

Human Permanent Ectoparasites; Recent Advances on Biology and Clinical Significance of Demodex Mites: Narrative Review Article

PubMed Central

CHEN, WenChieh; DZIKA, Ewa; KORYCIŃSKA, Joanna

2017-01-01

Background: Demodex is a genus of mites living predominantly in mammalian pilosebaceous units. They are commonly detected in the skin of face, with increasing numbers in inflammatory lesions. Causation between Demodex mites and inflammatory diseases, such as rosacea, blepharitis, perioral and seborrhoeic dermatitis or chalazion, is controversially discussed. Clinical observations indicate a primary form of human Demodex infection. The aim of this review was to highlight the biological aspects of Demodex infestation and point out directions for the future research. Methods: We conducted a broad review based on the electronic database sources such as MEDLINE, PubMed and Scopus with regard to the characteristics of the Demodex species, methods of examination and worldwide epidemiology, molecular studies and its role in the complex human ecosystem. Results: Demodex mites are organisms with a worldwide importance as they act in indicating several dermatoses, under certain conditions. However, correlations between Demodex and other parasites or microorganisms occupying one host, as well as interactions between these arachnids and its symbiotic bacteria should be considered. There are few methods of human mites’ examination depending on purpose of the study. Nevertheless, paying attention must be needed as polymorphism of Demodex species has been reported. Conclusion: Overall, the present review will focus on different aspects of Demodex mites’ biology and significance of these arachnids in human’s health. PMID:28747952

Spiders in dermatology.

PubMed

Kang, Jun K; Bhate, Chinmoy; Schwartz, Robert A

2014-09-01

Spider bites represent an unusual and potentially over-represented clinical diagnosis. Despite a common fear of spiders, known as arachnophobia, current knowledge suggests that only a small number of families within the order Araneae are medically relevant. Moreover, most cutaneous spider reactions, including both evenomations and physical trauma, produce mild, local symptoms which may be managed with supportive care alone. The differential diagnosis for spider bites may be broad, especially if the offending arachnid is not seen or found. We describe a series of spiders relevant to the dermatologist in the United States.

Late summer food habits of three heron species in northeastern Louisiana

USGS Publications Warehouse

Niethammer, K.R.; Kaiser, M.S.

1983-01-01

Yellow-crowned Night-Herons (Nycticorax violaceus), Little Blue Herons (Egretta caerulea), and Green-backed Herons (Butorides striatus) collected in northeastern Louisiana from July-September 1980 exhibited different diets. Yellow-crowned Night-Herons fed mostly on crayfish (74% by weight) and Green-backed Herons fed primarily on fish (93% by weight). The diet of Little Blue Herons was diverse, including fish (61%), crustaceans (11%), insects (13%), and arachnids (14%). Yellow-crowned Night-Herons captured larger prey than did either of the smaller herons. Green-backed Herons took larger prey and a greater range of prey sizes than did the larger Little Blue Herons.

Sound Source Localization through 8 MEMS Microphones Array Using a Sand-Scorpion-Inspired Spiking Neural Network.

PubMed

Beck, Christoph; Garreau, Guillaume; Georgiou, Julius

2016-01-01

Sand-scorpions and many other arachnids perceive their environment by using their feet to sense ground waves. They are able to determine amplitudes the size of an atom and locate the acoustic stimuli with an accuracy of within 13° based on their neuronal anatomy. We present here a prototype sound source localization system, inspired from this impressive performance. The system presented utilizes custom-built hardware with eight MEMS microphones, one for each foot, to acquire the acoustic scene, and a spiking neural model to localize the sound source. The current implementation shows smaller localization error than those observed in nature.

Gravito-inertial sensitivity of the spider - Araneus sericatus

NASA Technical Reports Server (NTRS)

Finck, A.

1982-01-01

The gravito-inertial transfer function of the orb-weaving spider was evaluated by changes in the cardiac reflex. A non-intrusive method, using a laser system recorded the cardiac pulse. Between 1.001 and 1.5 Gz the data are 'best-fit' by a log function (r-squared 0.92). The response of the neurogenic heart is seen to be a good dependent variable for invetebrate research. The arachnid lyriform organ has those qualities which complement the obtained gravity function. It is hypothesized that the cardiac pump maintains the spiders equilibrium in the gravito-inertial field.

Index to the known fossil insects of the world, including myriapods and arachnids

USGS Publications Warehouse

Scudder, Samuel Hubbard

1891-01-01

With the view of furthering study in the too neglected field of fossil insects, I transmit herewith for publication the card catalogue of described fossil insects which I have used for twenty years and kept constantly up to date, and which has greatly facilitated my own researches. It is believed to be practically complete. At least where insects are figured, and in many other cases where they are the first or only references from a given locality, entries are given where only the genus, the family, or even the order is mentioned. This has been done because the early literature of fossil insects is essentially vague and general, but it should not for that reason be wholly overlooked ; and to-day our knowledge of the occurrence of insects of a particular locality, even when of recent discovery, is not infrequently confined to statements of a general nature, which, if not brought to view or mind in a list like this, would be lost sight of, while their recognition may lead to further local investigation, to the earlier benefit of science.It is in no sense a systematic catalogue, and except occasionally in the notes contains no immediate results of investigation. No questions of synonymy are settled. The entries are made as the authors quoted gave them, with only the corrections of spelling required; it follows that the same insect appears at several points, to which the student is referred by full cross-references, and that more than one insect may (though probably rarely does) figure under one name. In one or two such instances, where the same name has been given by inadvertence to two totally different creatures, the later one is separated from the earlier.For convenience' sake, the entries are grouped into large sections, nearly identical with those I have employed in my systematic review of fossil insects (Bulletin 31, U. S. Geological Survey), by which method the insects from the Primary, Secondary, and Tertiary rocks are kept distinct; but otherwise the entries are purely alphabetical under the orders. It should be noticed, however, that the vague references to groups higher than genera are brought together at the beginning of each alphabet, first the most vague, and then those which permit some alphabetization. In these cases the primary or secondary alphabetization is first by authors, second by dates, and in all cases where under one entry there is more than one date the order therein is chronological.In a previous bulletin (Bulletin 69, U. S. Geological Survey) is given a complete bibliography of the literature from which these entries are taken, and the two works are thus complementary to each other.

The house spider genome reveals an ancient whole-genome duplication during arachnid evolution.

PubMed

Schwager, Evelyn E; Sharma, Prashant P; Clarke, Thomas; Leite, Daniel J; Wierschin, Torsten; Pechmann, Matthias; Akiyama-Oda, Yasuko; Esposito, Lauren; Bechsgaard, Jesper; Bilde, Trine; Buffry, Alexandra D; Chao, Hsu; Dinh, Huyen; Doddapaneni, HarshaVardhan; Dugan, Shannon; Eibner, Cornelius; Extavour, Cassandra G; Funch, Peter; Garb, Jessica; Gonzalez, Luis B; Gonzalez, Vanessa L; Griffiths-Jones, Sam; Han, Yi; Hayashi, Cheryl; Hilbrant, Maarten; Hughes, Daniel S T; Janssen, Ralf; Lee, Sandra L; Maeso, Ignacio; Murali, Shwetha C; Muzny, Donna M; Nunes da Fonseca, Rodrigo; Paese, Christian L B; Qu, Jiaxin; Ronshaugen, Matthew; Schomburg, Christoph; Schönauer, Anna; Stollewerk, Angelika; Torres-Oliva, Montserrat; Turetzek, Natascha; Vanthournout, Bram; Werren, John H; Wolff, Carsten; Worley, Kim C; Bucher, Gregor; Gibbs, Richard A; Coddington, Jonathan; Oda, Hiroki; Stanke, Mario; Ayoub, Nadia A; Prpic, Nikola-Michael; Flot, Jean-François; Posnien, Nico; Richards, Stephen; McGregor, Alistair P

2017-07-31

The duplication of genes can occur through various mechanisms and is thought to make a major contribution to the evolutionary diversification of organisms. There is increasing evidence for a large-scale duplication of genes in some chelicerate lineages including two rounds of whole genome duplication (WGD) in horseshoe crabs. To investigate this further, we sequenced and analyzed the genome of the common house spider Parasteatoda tepidariorum. We found pervasive duplication of both coding and non-coding genes in this spider, including two clusters of Hox genes. Analysis of synteny conservation across the P. tepidariorum genome suggests that there has been an ancient WGD in spiders. Comparison with the genomes of other chelicerates, including that of the newly sequenced bark scorpion Centruroides sculpturatus, suggests that this event occurred in the common ancestor of spiders and scorpions, and is probably independent of the WGDs in horseshoe crabs. Furthermore, characterization of the sequence and expression of the Hox paralogs in P. tepidariorum suggests that many have been subject to neo-functionalization and/or sub-functionalization since their duplication. Our results reveal that spiders and scorpions are likely the descendants of a polyploid ancestor that lived more than 450 MYA. Given the extensive morphological diversity and ecological adaptations found among these animals, rivaling those of vertebrates, our study of the ancient WGD event in Arachnopulmonata provides a new comparative platform to explore common and divergent evolutionary outcomes of polyploidization events across eukaryotes.

A new scorpion species of genus Diplocentrus Peters, 1861 (Scorpiones: Diplocentridae) endemic to Islas de la Bahia, Honduras.

PubMed

Sagastume-Espinoza, Kevin O; Longhorn, Stuart J; Santibáñez-López, Carlos E

2015-07-01

Three species of genus Diplocentrus are found in north-northwestern Honduras. These species represent the southern east limits of Diplocentrus' distribution. In recent years, a broad survey of arachnids in Honduras has yielded a collection of several specimens of an undescribed species from two islands in northern Honduras. This new species represents the second species of the genus inhabiting an island. The present contribution describes this new species, and compares it against its most similar relatives. A dichotomous key for the identification of the species of Diplocentrus in Honduras is also included. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

The phylogeny of fossil whip spiders.

PubMed

Garwood, Russell J; Dunlop, Jason A; Knecht, Brian J; Hegna, Thomas A

2017-04-21

Arachnids are a highly successful group of land-dwelling arthropods. They are major contributors to modern terrestrial ecosystems, and have a deep evolutionary history. Whip spiders (Arachnida, Amblypygi), are one of the smaller arachnid orders with ca. 190 living species. Here we restudy one of the oldest fossil representatives of the group, Graeophonus anglicus Pocock, 1911 from the Late Carboniferous (Duckmantian, ca. 315 Ma) British Middle Coal Measures of the West Midlands, UK. Using X-ray microtomography, our principal aim was to resolve details of the limbs and mouthparts which would allow us to test whether this fossil belongs in the extant, relict family Paracharontidae; represented today by a single, blind species Paracharon caecus Hansen, 1921. Tomography reveals several novel and significant character states for G. anglicus; most notably in the chelicerae, pedipalps and walking legs. These allowed it to be scored into a phylogenetic analysis together with the recently described Paracharonopsis cambayensis Engel & Grimaldi, 2014 from the Eocene (ca. 52 Ma) Cambay amber, and Kronocharon prendinii Engel & Grimaldi, 2014 from Cretaceous (ca. 99 Ma) Burmese amber. We recovered relationships of the form ((Graeophonus (Paracharonopsis + Paracharon)) + (Charinus (Stygophrynus (Kronocharon (Charon (Musicodamon + Paraphrynus)))))). This tree largely reflects Peter Weygoldt's 1996 classification with its basic split into Paleoamblypygi and Euamblypygi lineages; we were able to score several of his characters for the first time in fossils. Our analysis draws into question the monophyly of the family Charontidae. Our data suggest that Graeophonus is a crown group amblypygid, and falls within a monophyletic Paleoamblypgi clade, but outside the family Paracharontidae (= Paracharonopsis + Paracharon). Our results also suggest a new placement for the Burmese amber genus Kronocharon, a node further down from its original position. Overall, we offer a

Intrinsic resistance to the lethal effects of x-irradiation in insect and arachnid cells

PubMed Central

Koval, Thomas M.

1983-01-01

Twelve cell lines representing 10 genera of three orders (Diptera, Lepidoptera, and Orthoptera) of the class Insecta and one cell line (Acarina) from the class Arachnida were examined to discern their sensitivity to the lethal effects of x-irradiation. Radiosensitivity was measured by a combination of colony formation and population growth curve techniques. Each of these arthropod cell lines is significantly more radioresistant than mammalian cells, though the degree of resistance varies greatly with order. Dipteran cells are 3 to 9 times and lepidopteran cells 52 to 104 times more radioresistant than mammalian cells. Orthopteran and acarine cells are intermediate in radiosensitivity between dipteran and lepidopteran cells. These cells, especially the lepidopteran, should be valuable in determining the molecular nature of repair mechanisms that result in resistance to ionizing radiation. PMID:16593348

Southwest Caves Reveal New Forms of Life

USGS Publications Warehouse

Wynne, J. Judson; Drost, Charles

2009-01-01

Caves in northern Arizona and western New Mexico are being researched and inventoried by scientists with the U.S. Geological Survey and cooperating agencies. Southwestern caves have been little studied, and scientists are now finding that these lightless and nutrient-poor natural systems are home to life forms found nowhere else on Earth. This research has identified unique communities of arthropods (insects, arachnids, and crustaceans) that include 3 new genera, or groups of species, and at least 15 new species - some only known to exist in a single cave. This exciting research is yielding information that will be used by resource managers to better understand and protect fragile and important Southwestern cave ecosystems.

Chemosystematics in the Opiliones (Arachnida): a comment on the evolutionary history of alkylphenols and benzoquinones in the scent gland secretions of Laniatores.

PubMed

Raspotnig, Günther; Bodner, Michaela; Schäffer, Sylvia; Koblmüller, Stephan; Schönhofer, Axel; Karaman, Ivo

2015-04-01

Large prosomal scent glands constitute a major synapomorphic character of the arachnid order Opiliones. These glands produce a variety of chemicals very specific to opilionid taxa of different taxonomic levels, and thus represent a model system to investigate the evolutionary traits in exocrine secretion chemistry across a phylogenetically old group of animals. The chemically best-studied opilionid group is certainly Laniatores, and currently available chemical data allow first hypotheses linking the phylogeny of this group to the evolution of major chemical classes of secretion chemistry. Such hypotheses are essential to decide upon a best-fitting explanation of the distribution of scent-gland secretion compounds across extant laniatorean taxa, and hence represent a key toward a well-founded opilionid chemosystematics.

Mi Casa es Su Casa: how an intracellular symbiont manipulates host biology.

PubMed

Bhattacharya, Tamanash; Newton, Irene L G

2017-10-27

Wolbachia pipientis, the most common intracellular infection on the planet, infects 40% of insects as well as nematodes, isopods and arachnids. Wolbachia are obligately intracellular and challenging to study; there are no genetic tools for manipulating Wolbachia nor can they be cultured outside of host cells. Despite these roadblocks, the research community has defined a set of Wolbachia loci involved in host interaction: Wolbachia effectors. Through the use of Drosophila genetics, surrogate systems and biochemistry, the field has begun to define the toolkit Wolbachia use for host manipulation. Below we review recent findings identifying these Wolbachia effectors and point to potential, as yet uncharacterized, links between known phenotypes induced by Wolbachia infection and predicted effectors. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

A theory of vibrational prey localization in two dimensions: the sand scorpion

NASA Astrophysics Data System (ADS)

van Hemmen, J. Leo

2000-03-01

Sand scorpions, and many other arachnids, find their prey at night by localizing the source of mechanical waves produced by prey movements. Substrate vibrations propagating through sand evoke stimulus-locked action potentials from slit sensilla on the scorpion's eight `feet' (tarsi). We present a neuronal model to account for stimulus angle determination in a two-dimensional plane using a population of second-order neurons, each receiving excitatory input from one tarsus and inhibition from a triad opposite to it. This input opens a time window whose width determines the firing probability of each of the second-order neurons. The population then `votes' for the direction. Stochastic resonance is realized through tuning the balance between excitation and inhibition. The agreement with behavioral experiments on sand scorpions is excellent.

Chemosystematics in the Opiliones (Arachnida): a comment on the evolutionary history of alkylphenols and benzoquinones in the scent gland secretions of Laniatores

PubMed Central

Raspotnig, Günther; Bodner, Michaela; Schäffer, Sylvia; Koblmüller, Stephan; Schönhofer, Axel; Karaman, Ivo

2015-01-01

Large prosomal scent glands constitute a major synapomorphic character of the arachnid order Opiliones. These glands produce a variety of chemicals very specific to opilionid taxa of different taxonomic levels, and thus represent a model system to investigate the evolutionary traits in exocrine secretion chemistry across a phylogenetically old group of animals. The chemically best-studied opilionid group is certainly Laniatores, and currently available chemical data allow first hypotheses linking the phylogeny of this group to the evolution of major chemical classes of secretion chemistry. Such hypotheses are essential to decide upon a best-fitting explanation of the distribution of scent-gland secretion compounds across extant laniatorean taxa, and hence represent a key toward a well-founded opilionid chemosystematics. PMID:26074662

Predation among armored arachnids: Bothriurus bonariensis (Scorpions, Bothriuridae) versus four species of harvestmen (Harvestmen, Gonyleptidae).

PubMed

Albín, Andrea; Toscano-Gadea, Carlos A

2015-12-01

Natural selection shapes prey-predator relationships and their behavioral adaptations, which seek to maximize capture success in the predator and avoidance in the prey. We tested the ability of adults of the scorpion Bothriurus bonariensis (Bothriuridae) to prey on synchronous and sympatric adults harvestmen of Acanthopachylus aculeatus, Discocyrtus prospicuus, Parampheres bimaculatus and Pachyloides thorellii (Gonyleptidae). In 72.5% of the cases B. bonariensis tried to prey on the harvestmen. The most successful captures occurred in the trials against A. aculeatus and D. prospicuus. In all the successful attacks the scorpions stung the prey between the chelicerae and consumed them, starting by the anterior portion of their bodies. The harvestmen used different defensive strategies such as fleeing before or after contact with the predator, exudating of chemical substances or staying still at the scorpion's touch. When scorpions contacted the chemical substances secreted by the harvestmen, they immediately rubbed the affected appendix against the substrate. However, exudating of chemical substances did not prevent, in any case, predation on the harvestmen. This is the first study showing the ability of scorpions to prey on different species of harvestmen, as well as the capture and defensive behaviors used by the predator and the prey. Copyright © 2015 Elsevier B.V. All rights reserved.

Fish and shellfish allergy.

PubMed

Wild, Laurianne G; Lehrer, Samuel B

2005-01-01

Fish and shellfish are important in the American diet and economy. Nearly $27 billion are spent each year in the United States on seafood products. Fish and shellfish are also important causes of food hypersensitivity. In fact, shellfish constitute the number one cause of food allergy in the American adult. During the past decade, much has been learned about allergens in fish and shellfish. The major allergens responsible for cross-reactivity among distinct species of fish and amphibians are parvalbumins. The major shellfish allergen has been identified as tropomyosin. Many new and important potential cross-reacting allergens have been identified within the fish family and between shellfish, arachnids, and insects. Extensive research is currently underway for the development of safer and more effective methods for the diagnosis and management of fish and shellfish hypersensitivity.

Environmental Adaptations, Ecological Filtering, and Dispersal Central to Insect Invasions.

PubMed

Renault, David; Laparie, Mathieu; McCauley, Shannon J; Bonte, Dries

2018-01-07

Insect invasions, the establishment and spread of nonnative insects in new regions, can have extensive economic and environmental consequences. Increased global connectivity accelerates rates of introductions, while climate change may decrease the barriers to invader species' spread. We follow an individual-level insect- and arachnid-centered perspective to assess how the process of invasion is influenced by phenotypic heterogeneity associated with dispersal and stress resistance, and their coupling, across the multiple steps of the invasion process. We also provide an overview and synthesis on the importance of environmental filters during the entire invasion process for the facilitation or inhibition of invasive insect population spread. Finally, we highlight important research gaps and the relevance and applicability of ongoing natural range expansions in the context of climate change to gain essential mechanistic insights into insect invasions.

Gravity Reception and Cardiac Function in the Spider

NASA Technical Reports Server (NTRS)

Finck, A.

1985-01-01

The following features of the arachnid gravity system were studied. (1) the absolute threshold to hyper-gz is quite low indicating fine proprioreceptive properties of the lyriform organ, the Gz/vibration detector; (2) the neurogenic heart of the spider is a good dependent variable for assessing its behavior to Gz and other stimuli which produce mechanical effects on the exoskeleton; (3) Not only is the cardiac response useful but it is now understood to be an integral part of the system which compensates for the consequences of gravity in the spider (an hydraulic leg extension); and (4) a theoretical model was proposed in which a mechanical amplifier, the leg lever, converts a weak force (at the tarsus) to a strong force (at the patella), capable of compressing the exoskeleton and consequently the lyriform receptor.

New species of Austropurcellia, cryptic short-range endemic mite harvestmen (Arachnida, Opiliones, Cyphophthalmi) from Australia’s Wet Tropics biodiversity hotspot

PubMed Central

Jay, Katya R.; Popkin-Hall, Zachary R.; Coblens, Michelle J.; Oberski, Jill T.; Sharma, Prashant P.; Boyer, Sarah L.

2016-01-01

Abstract The genus Austropurcellia is a lineage of tiny leaf-litter arachnids that inhabit tropical rainforests throughout the eastern coast of Queensland, Australia. The majority of their diversity is found within the Wet Tropics rainforests of northeast Queensland, an area known for its exceptionally high levels of biodiversity and endemism. Studying the biogeographic history of limited-dispersal invertebrates in the Wet Tropics can provide insight into the role of climatic changes such as rainforest contraction in shaping rainforest biodiversity patterns. Here we describe six new species of mite harvestmen from the Wet Tropics rainforests, identified using morphological data, and discuss the biogeography of Austropurcellia with distributions of all known species. With this taxonomic contribution, the majority of the known diversity of the genus has been documented. PMID:27199608

Females are the brighter sex: Differences in external fluorescence across sexes and life stages of a crab spider.

PubMed

Brandt, Erin E; Masta, Susan E

2017-01-01

Fluorescence is increasingly recognized to be widespread in nature. In particular, some arachnids fluoresce externally, and in spiders the hemolymph fluoresces. In this study, we examined the external fluorescence and the fluorophores of different sexes and life stages of the crab spider Misumena vatia (Clerk 1757), a sit-and-wait predator that feeds on insects as they visit flowers. We designed novel instrumentation to measure external fluorescence in whole specimens. We found that although males and females possess internal fluorophores with similar properties, the external expression of fluorescence varies across sexes and life stages. Spiders fluoresce brightly as immatures. Females maintain their brightness to adulthood, whereas males become increasingly dim as they mature. We suggest that external fluorescence likely contributes to visual signaling in these animals, and that it differs between the sexes as a result of differences in foraging ecology and behavior.

The evolution of Dscam genes across the arthropods.

PubMed

Armitage, Sophie A O; Freiburg, Rebecca Y; Kurtz, Joachim; Bravo, Ignacio G

2012-04-13

One way of creating phenotypic diversity is through alternative splicing of precursor mRNAs. A gene that has evolved a hypervariable form is Down syndrome cell adhesion molecule (Dscam-hv), which in Drosophila melanogaster can produce thousands of isoforms via mutually exclusive alternative splicing. The extracellular region of this protein is encoded by three variable exon clusters, each containing multiple exon variants. The protein is vital for neuronal wiring where the extreme variability at the somatic level is required for axonal guidance, and it plays a role in immunity where the variability has been hypothesised to relate to recognition of different antigens. Dscam-hv has been found across the Pancrustacea. Additionally, three paralogous non-hypervariable Dscam-like genes have also been described for D. melanogaster. Here we took a bioinformatics approach, building profile Hidden Markov Models to search across species for putative orthologs to the Dscam genes and for hypervariable alternatively spliced exons, and inferring the phylogenetic relationships among them. Our aims were to examine whether Dscam orthologs exist outside the Bilateria, whether the origin of Dscam-hv could lie outside the Pancrustacea, when the Dscam-like orthologs arose, how many alternatively spliced exons of each exon cluster were present in the most common recent ancestor, and how these clusters evolved. Our results suggest that the origin of Dscam genes may lie after the split between the Cnidaria and the Bilateria and supports the hypothesis that Dscam-hv originated in the common ancestor of the Pancrustacea. Our phylogeny of Dscam gene family members shows six well-supported clades: five containing Dscam-like genes and one containing all the Dscam-hv genes, a seventh clade contains arachnid putative Dscam genes. Furthermore, the exon clusters appear to have experienced different evolutionary histories. Dscam genes have undergone independent duplication events in the insects and

The evolution of Dscam genes across the arthropods

PubMed Central

2012-01-01

Background One way of creating phenotypic diversity is through alternative splicing of precursor mRNAs. A gene that has evolved a hypervariable form is Down syndrome cell adhesion molecule (Dscam-hv), which in Drosophila melanogaster can produce thousands of isoforms via mutually exclusive alternative splicing. The extracellular region of this protein is encoded by three variable exon clusters, each containing multiple exon variants. The protein is vital for neuronal wiring where the extreme variability at the somatic level is required for axonal guidance, and it plays a role in immunity where the variability has been hypothesised to relate to recognition of different antigens. Dscam-hv has been found across the Pancrustacea. Additionally, three paralogous non-hypervariable Dscam-like genes have also been described for D. melanogaster. Here we took a bioinformatics approach, building profile Hidden Markov Models to search across species for putative orthologs to the Dscam genes and for hypervariable alternatively spliced exons, and inferring the phylogenetic relationships among them. Our aims were to examine whether Dscam orthologs exist outside the Bilateria, whether the origin of Dscam-hv could lie outside the Pancrustacea, when the Dscam-like orthologs arose, how many alternatively spliced exons of each exon cluster were present in the most common recent ancestor, and how these clusters evolved. Results Our results suggest that the origin of Dscam genes may lie after the split between the Cnidaria and the Bilateria and supports the hypothesis that Dscam-hv originated in the common ancestor of the Pancrustacea. Our phylogeny of Dscam gene family members shows six well-supported clades: five containing Dscam-like genes and one containing all the Dscam-hv genes, a seventh clade contains arachnid putative Dscam genes. Furthermore, the exon clusters appear to have experienced different evolutionary histories. Conclusions Dscam genes have undergone independent

A new lipid carrier protein in the cattle tick Rhipicephalus microplus.

PubMed

Kluck, George E G; Silva Cardoso, Lívia; De Cicco, Nuccia N T; Lima, Michele S; Folly, Evelize; Atella, Georgia C

2018-05-01

Tick infestation in cattle reflects the main cause of economic loss to cattle producers. This is due to several reasons but mainly to their ability to feed on blood and generate a huge amount of eggs. Lipid transport in arthropods is achieved by highly specialized hemolymphatic lipoproteins, which resemble those described in vertebrate blood. Such lipoproteins continuously deliver lipids through the blood to growing eggs. The injection of radioactive [ 3 H] palmitic acid into tick hemocoel showed that the gut, ovary, fat body and Gene's organ were the main organs of incorporation of this labeled fatty acid. The rate of [ 3 H] palmitic acid incorporation by the organs was high up to 30 min after injection. The [ 3 H] palmitic acid incorporated by these organs was later found in phospholipids and neutral lipids. Here, we describe the purification and characterization of a key player of lipid dynamics in tick hemolymph. The Rhipicephalus microplus lipid-apolipoprotein complex (RmLCP) is a new high-density lipoprotein (1.18 g/mL), which accounts for over 90% of [ 3 H] palmitic acid present in the hemolymph. It has a native molecular weight of 420 kDa and is composed of one subunit of 122 kDa. Protein identification analysis of RmLPC subunit showed two better hits: vitellogenin 2 (23% protein coverage) and vitellogenin 5 (29% protein coverage), respectively and similarities with hemolymphatic apolipoproteins of arachnids such as the tick Ixodes scapularis (80%), the mite Galendromus occidentalis (44%) and the spider Parasteatoda tepidariorum (43%) and also for the insects Locusta migratoria (45%), Drosophila melanogaster (42%) and Manduca sexta (47%) to vitellogenin 2 and tick Ixodes scapularis (83%), the crab Limulus polyphemus (55%) and the oyster Crassostrea gigas (55%) to vitellogenin 5. Furthermore, it shows a distinct lipid composition from most arthropod lipoproteins, being composed of 40% free cholesterol, 27% phospholipids, 20% triacylglycerol and 15

The Chilean Recluse Spider (Araneae: Sicariidae) Displays Behavioral Responses to Conspecific Odors, but Not to Several General Odorants.

PubMed

Calbiague, Victor Manuel; Olivares, Jesus; Olivares, Erick; Schmachtenberg, Oliver

2017-09-01

Spiders of the family Sicariidae pose a serious threat to affected populations, and Loxosceles laeta (Nicolet) is considered the most venomous species. Development of nontoxic olfaction-based spider repellents or traps is hindered by a current lack of knowledge regarding olfactory system function in arachnids. In the present study, general plant odorants and conspecific odors were tested for behavioral responses in L. laeta. Although general odorants triggered neither attraction nor aversion, conspecific odor of the opposite sex caused aversion in females, and attraction in males. These results support the presence of a specific olfactory system for the detection of conspecifics in L. laeta, but suggest the absence of a broadly tuned system for general odorant detection in this species. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Food of nestling green-backed herons in West Central Mississippi

USGS Publications Warehouse

Ensor, K.L.; Dusi, J.L.; White, D.H.

1986-01-01

Food habits of the green-backed heron have received much attention recently, though little data exists in the literature on food items fed to nestlings. Analysis of 74 nestling boluses collected between 5 May and 10 July 1985 included four categories: a) number of prey items, b) % of total individuals by number, c) % frequency of herons with that particular prey item, d) % of total diet by weight. By class, fish dominated the diet, followed by insects, amphibians, crustaceans, and arachnids in descending order. Amphibians, however, had a higher % of total diet by weight than insects. The mosquitofish (Gambusia affinis) made up the largest part of the diet by # of prey items and % of total individuals by #. Bowfin (Amia calva) was the major prey item by weight. Back-swimmers (F. Notonectidae) occurred in more boluses than any other prey item. Lengths of prey items by class will also be discussed.

Females are the brighter sex: Differences in external fluorescence across sexes and life stages of a crab spider

PubMed Central

Brandt, Erin E.

2017-01-01

Fluorescence is increasingly recognized to be widespread in nature. In particular, some arachnids fluoresce externally, and in spiders the hemolymph fluoresces. In this study, we examined the external fluorescence and the fluorophores of different sexes and life stages of the crab spider Misumena vatia (Clerk 1757), a sit-and-wait predator that feeds on insects as they visit flowers. We designed novel instrumentation to measure external fluorescence in whole specimens. We found that although males and females possess internal fluorophores with similar properties, the external expression of fluorescence varies across sexes and life stages. Spiders fluoresce brightly as immatures. Females maintain their brightness to adulthood, whereas males become increasingly dim as they mature. We suggest that external fluorescence likely contributes to visual signaling in these animals, and that it differs between the sexes as a result of differences in foraging ecology and behavior. PMID:28467416

ST. LOUIS ENCEPHALITIS

PubMed Central

Smith, Margaret G.; Blattner, Russell J.; Heys, Florence M.

1947-01-01

Transmission of the virus of St. Louis encephalitis to normal chickens by the bite of infected mites (Dermanyssus gallinae) has been demonstrated. Both experimentally infected and naturally infected mites were shown to be capable of transferring the virus of St. Louis encephalitis to chickens by bite. Virus is present in the blood of such chickens in small amounts, so that demonstration of viremia was possible only by utilizing chorioallantoic passage in hens' eggs. However, there is sufficient virus present in the blood for uninfected chicken mites to acquire the virus by feeding on chickens in which viremia has resulted from previous bite of infected mites. Thus it has been shown that the arachnid vector Dermanyssus gallinae is capable of transmitting the virus of St. Louis encephalitis to normal chickens by bite and that such chickens can serve as a source of virus for uninfected mites. PMID:19871673

The genome of Mesobuthus martensii reveals a unique adaptation model of arthropods

PubMed Central

Cao, Zhijian; Yu, Yao; Wu, Yingliang; Hao, Pei; Di, Zhiyong; He, Yawen; Chen, Zongyun; Yang, Weishan; Shen, Zhiyong; He, Xiaohua; Sheng, Jia; Xu, Xiaobo; Pan, Bohu; Feng, Jing; Yang, Xiaojuan; Hong, Wei; Zhao, Wenjuan; Li, Zhongjie; Huang, Kai; Li, Tian; Kong, Yimeng; Liu, Hui; Jiang, Dahe; Zhang, Binyan; Hu, Jun; Hu, Youtian; Wang, Bin; Dai, Jianliang; Yuan, Bifeng; Feng, Yuqi; Huang, Wei; Xing, Xiaojing; Zhao, Guoping; Li, Xuan; Li, Yixue; Li, Wenxin

2013-01-01

Representing a basal branch of arachnids, scorpions are known as ‘living fossils’ that maintain an ancient anatomy and are adapted to have survived extreme climate changes. Here we report the genome sequence of Mesobuthus martensii, containing 32,016 protein-coding genes, the most among sequenced arthropods. Although M. martensii appears to evolve conservatively, it has a greater gene family turnover than the insects that have undergone diverse morphological and physiological changes, suggesting the decoupling of the molecular and morphological evolution in scorpions. Underlying the long-term adaptation of scorpions is the expansion of the gene families enriched in basic metabolic pathways, signalling pathways, neurotoxins and cytochrome P450, and the different dynamics of expansion between the shared and the scorpion lineage-specific gene families. Genomic and transcriptomic analyses further illustrate the important genetic features associated with prey, nocturnal behaviour, feeding and detoxification. The M. martensii genome reveals a unique adaptation model of arthropods, offering new insights into the genetic bases of the living fossils. PMID:24129506

Visualisation of insect tracheal systems by lactic acid immersion.

PubMed

Ruan, Y; Li, Y; Zhang, M; Chen, X; Liu, Z; Wang, S; Jiang, S

2018-05-15

The endeavours to reveal the tracheal system of insects and some arachnids has a long history. The traditional way to observe a tracheal system in an insect body is by utilising the glycerin immersion method. In this study, we developed the lactic acid immersion method, which reveals a more complete tracheal system. By mounting various types of live specimens or body parts directly into lactic acid, multiple intact and complex tracheal systems were clearly visualised. The lactic acid immersion contributed to revealing tracheal systems by penetrating body tissue while reserving enough time for observation before the penetration of the tracheae. Preliminary comparisons were conducted between lactic acid and other mediae, including glycerin. It turned out that lactic acid immersion provides better details and more distinct structures. In our test, the optimal time for observing the tracheal system was 10-25 min after the organism was immersed in lactic acid. © 2018 The Authors Journal of Microscopy © 2018 Royal Microscopical Society.

The snakes of Osun Grove: a world heritage site in Osogbo, Nigeria.

PubMed

Akinpelu, Akinsola I; Areo, Adebowale

2007-06-01

The Osun Grove, Osogbo, Nigeria, is a protected area covered by riparian forest, dry high forest and derived savanna. In January and June 2000 a total of 25 of snake species were recorded with Afronatrix anoscopus and Calabaria reinhardti being prominent. The incidence of Philothamnus semivariegatus, a savanna species, may be the result of the invasive savanna produced by farming activities around the grove. Nine species, led by A. anoscopus, accounted for 69.7% of the snake community. The dominant species are either aquatic or terrestrial, with the exception of Boiga blandingi and Dendroaspis viridis that can be both arboreal and terrestrial, and C. reinhardti that is fossorial. Arboreal species mostly preyed on tree frogs and birds including eggs and nestlings, and the aquatic forms preyed on fish and frogs. Mammals, reptiles and toads constitute the prey items of terrestrial species while fossorial species feed on annelids, molluscs, arachnids, myriapods, hexapods, amphibians, reptiles and mammals.

Evolutionary biology of harvestmen (Arachnida, Opiliones).

PubMed

Giribet, Gonzalo; Sharma, Prashant P

2015-01-07

Opiliones are one of the largest arachnid orders, with more than 6,500 species in 50 families. Many of these families have been erected or reorganized in the last few years since the publication of The Biology of Opiliones. Recent years have also seen an explosion in phylogenetic work on Opiliones, as well as in studies using Opiliones as test cases to address biogeographic and evolutionary questions more broadly. Accelerated activity in the study of Opiliones evolution has been facilitated by the discovery of several key fossils, including the oldest known Opiliones fossil, which represents a new, extinct suborder. Study of the group's biology has also benefited from rapid accrual of genomic resources, particularly with respect to transcriptomes and functional genetic tools. The rapid emergence and utility of Phalangium opilio as a model for evolutionary developmental biology of arthropods serve as demonstrative evidence of a new area of study in Opiliones biology, made possible through transcriptomic data.

Antimicrobial Activity and Stability of Short and Long Based Arachnid Synthetic Peptides in the Presence of Commercial Antibiotics.

PubMed

Arenas, Ivan; Villegas, Elba; Walls, Oliver; Barrios, Humberto; Rodríguez, Ramon; Corzo, Gerardo

2016-02-17

Four antimicrobial peptides (AMPs) named Pin2[G], Pin2[14], P18K and FA1 were chemically synthesized and purified. The four peptides were evaluated in the presence of eight commercial antibiotics against four microorganisms of medical importance: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. The commercial antibiotics used were amoxicillin, azithromycin, ceftriaxone, gentamicin, levofloxacin, sulfamethoxazole, trimethoprim and vancomycin. The best AMP against P. aeruginosa was the peptide FA1, and the best AMP against S. aureus was Pin2[G]. Both FA1 and Pin2[G] were efficient against E. coli, but they were not effective against K. pneumoniae. As K. pneumoniae was resistant to most of the commercial antibiotics, combinations of the AMPs FA1 and Pin2[G] were prepared with these antibiotics. According to the fractional inhibitory concentration (FIC) index, the best antimicrobial combinations were obtained with concomitant applications of mixtures of FA1 with levofloxacin and sulfamethoxazole. However, combinations of FA1 or Pin2[G] with other antibiotics showed that total inhibitory effect of the combinations were greater than the sum of the individual effects of either the antimicrobial peptide or the antibiotic. We also evaluated the stability of the AMPs. The AMP Pin2[G] manifested the best performance in saline buffer, in supernatants of bacterial growth and in human blood plasma. Nevertheless, all AMPs were cleaved using endoproteolytic enzymes. These data show advantages and disadvantages of AMPs for potential clinical treatments of bacterial infections, using them in conjunction with commercial antibiotics.

Grassland birds wintering at U.S. Navy facilities in southern Texas

USGS Publications Warehouse

Woodin, Marc C.; Skoruppa, Mary Kay; Bryan, Pearce D.; Ruddy, Amanda J.; Hickman, Graham C.

2010-01-01

Grassland birds have undergone widespread decline throughout North America during the past several decades. Causes of this decline include habitat loss and fragmentation because of conversion of grasslands to cropland, afforestation in the East, brush and shrub invasion in the Southwest and western United States, and planting of exotic grass species to enhance forage production. A large number of exotic plant species, including grasses, have been introduced in North America, but most research on the effects of these invasions on birds has been limited to breeding birds, primarily those in northern latitudes. Research on the effects of exotic grasses on birds in winter has been extremely limited.This is the first study in southern Texas to examine and compare winter bird responses to native and exotic grasslands. This study was conducted during a period of six years (2003–2009) on United States Navy facilities in southern Texas including Naval Air Station–Corpus Christi, Naval Air Station–Kingsville, Naval Auxiliary Landing Field Waldron, Naval Auxiliary Landing Field Orange Grove, and Escondido Ranch, all of which contained examples of native grasslands, exotic grasslands, or both. Data from native and exotic grasslands were collected and compared for bird abundance and diversity; ground cover, vegetation density, and floristic diversity; bird and vegetation relationships; diversity of insects and arachnids; and seed abundance and diversity. Effects of management treatments in exotic grasslands were evaluated by comparing numbers and diversity of birds and small mammals in mowed, burned, and control areas.To determine bird abundance and bird species richness, birds were surveyed monthly (December–February) during the winters of 2003–2008 in transects (100 meter × 20 meter) located in native and exotic grasslands distributed at all five U.S. Navy facilities. To compare vegetation in native and exotic grasslands, vegetation characteristics were measured

Insecticidal peptides from the theraposid spider Brachypelma albiceps: an NMR-based model of Ba2.

PubMed

Corzo, Gerardo; Bernard, Cedric; Clement, Herlinda; Villegas, Elba; Bosmans, Frank; Tytgat, Jan; Possani, Lourival D; Darbon, Herve; Alagón, Alejandro

2009-08-01

Soluble venom and purified fractions of the theraposid spider Brachypelma albiceps were screened for insecticidal peptides based on toxicity to crickets. Two insecticidal peptides, named Ba1 and Ba2, were obtained after the soluble venom was separated by high performance liquid chromatography and cation exchange chromatography. The two insecticidal peptides contain 39 amino acid residues and three disulfide bonds, and based on their amino acid sequence, they are highly identical to the insecticidal peptides from the theraposid spiders Aphonopelma sp. from the USA and Haplopelma huwenum from China indicating a relationship among these genera. Although Ba1 and Ba2 were not able to modify currents in insect and vertebrate cloned voltage-gated sodium ion channels, they have noteworthy insecticidal activities compared to classical arachnid insecticidal toxins indicating that they might target unknown receptors in insect species. The most abundant insecticidal peptide Ba2 was submitted to NMR spectroscopy to determine its 3-D structure; a remarkable characteristic of Ba2 is a cluster of basic residues, which might be important for receptor recognition.

Molecular characterization and evolutionary insights into potential sex-determination genes in the western orchard predatory mite Metaseiulus occidentalis (Chelicerata: Arachnida: Acari: Phytoseiidae).

PubMed

Pomerantz, Aaron F; Hoy, Marjorie A; Kawahara, Akito Y

2015-01-01

Little is known about the process of sex determination at the molecular level in species belonging to the subclass Acari, a taxon of arachnids that contains mites and ticks. The recent sequencing of the transcriptome and genome of the western orchard predatory mite Metaseiulus occidentalis allows investigation of molecular mechanisms underlying the biological processes of sex determination in this predator of phytophagous pest mites. We identified four doublesex-and-mab-3-related transcription factor (dmrt) genes, one transformer-2 gene, one intersex gene, and two fruitless-like genes in M. occidentalis. Phylogenetic analyses were conducted to infer the molecular relationships to sequences from species of arthropods, including insects, crustaceans, acarines, and a centipede, using available genomic data. Comparative analyses revealed high sequence identity within functional domains and confirmed that the architecture for certain sex-determination genes is conserved in arthropods. This study provides a framework for identifying potential target genes that could be implicated in the process of sex determination in M. occidentalis and provides insight into the conservation and change of the molecular components of sex determination in arthropods.

An optimized high quality male DNA extraction from spermatophores in open thelycum shrimp species.

PubMed

Planella, Laia; Heras, Sandra; Vera, Manuel; García-Marín, José-Luis; Roldán, María Inés

2017-09-01

The crucial step of most of the current genetic studies is the extraction of DNA of sufficient quantity and quality. Several genomic DNA isolation methods have been described to successfully obtain male DNA from shrimp species. However, all current protocols require invasive handling methods with males for DNA isolation. Using Aristeus antennatus as a model we tested a reliable non-invasive differential DNA extraction method to male DNA isolation from spermatophores attached to female thelycum. The present protocol provides high quality and quantity DNA for polymerase chain reaction amplification and male genotyping. This new approach could be useful to experimental shrimp culture to select sires with relevant genetic patterns for selective breeding programs. More importantly, it can be applied to identify the mating pairs and male structure in wild populations of species as A. antennatus, where males are often difficult to capture. Our method could be also valuable for biological studies on other spermatophore-using species, such as myriapods, arachnids and insects. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Infrared and Raman Study of the Recluse Spider Silk

NASA Astrophysics Data System (ADS)

Wang, S. L.; Wang, Qijue; Xing, Zhen; Schniepp, H. C.; Qazilbash, M. M.

Spider silk exhibits remarkable mechanical properties, such as high tensile strength and toughness. We want to gain insight into the composition and structure of spider silk to discover the origin of these properties. We are especially interested in the organization of the crystalline beta sheets that are expected to contribute to the high strength of the silk from the recluse spider, Loxosceles laeta. The recluse spider produces a silk that has a unique geometry amongst arachnids. We measure the silk's optical properties, particularly the infrared-active and Raman-active vibrations. Broadband infrared transmission spectra were collected in the spectral range between 600 cm-1 and 4000 cm-1, with light polarized parallel and perpendicular to the long axis of the silk. Raman micro-spectroscopy was performed in the spectral range 500 cm-1 and 4000 cm- 1 with a 514 nm laser. The infrared and Raman vibrational modes are fit with Lorentzian and pseudo-Voigt functions. The vibrational modes are assigned to specific structures and electronic bonds in the silk. This work was supported by NASA/ Virginia Space Grant Consortium.

A novel marine silk.

PubMed

Kronenberger, Katrin; Dicko, Cedric; Vollrath, Fritz

2012-01-01

The discovery of a novel silk production system in a marine amphipod provides insights into the wider potential of natural silks. The tube-building corophioid amphipod Crassicorophium bonellii produces from its legs fibrous, adhesive underwater threads that combine barnacle cement biology with aspects of spider silk thread extrusion spinning. We characterised the filamentous silk as a mixture of mucopolysaccharides and protein deriving from glands representing two distinct types. The carbohydrate and protein silk secretion is dominated by complex β-sheet structures and a high content of charged amino acid residues. The filamentous secretion product exits the gland through a pore near the tip of the secretory leg after having moved through a duct, which subdivides into several small ductules all terminating in a spindle-shaped chamber. This chamber communicates with the exterior and may be considered the silk reservoir and processing/mixing space, in which the silk is mechanically and potentially chemically altered and becomes fibrous. We assert that further study of this probably independently evolved, marine arthropod silk processing and secretion system can provide not only important insights into the more complex arachnid and insect silks but also into crustacean adhesion cements.

A classed and annotated bibliography of fossil insects

USGS Publications Warehouse

Scudder, Samuel Hubbard

1890-01-01

The present work is an extension to date of a bibliography published in 1882.  It has, however, been altered in a few details, and, besides being fuller, differs from that in being a classed list, the works and essays which cover the entire field (which embraces not only insects proper, but also myriapods and arachnids) being placed first, followed by the more special memoirs grouped first by times, next by classes orders, etc., the classification employed in my Systematic Review of Fossil Insects, being used as a convenient basis.  This will also form the basis of the Index to Known Fossil Insects, forming a later complementary bulletin.  The occasion for the publication of both of these at this time is the completion of the first extended account of the American Tertiary insects given in Vol XIII of the Hayden series of geological reports, by which the numbers of the European and American insects bear for the first time some sort of proper relation to each other, at least in the lower groups.  This makes an immediate "account of stock," to employ a commercial term, desirable.

IRRADIATION OF SCORPIONS OF THE SPECIES CENTRUROIDES LIMPIDUS WITH GAMMA RAYS (in Spanish)

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

Mazzotti, L.; Rhode, R.H.; Lopez, F.

Although radiation studies have been done on other Arthropoda, mainly with the purpose of their eradication, little is known about the effect of gamma rays on scorpions. In this study, four groups of 15 scorpions each were irradiated with gamma rays varying in dosage from 4500 to 11,500 r. After a dose of approximates 4500 r, apparently normal physical activity and food intake were maintained. Longest survival time in this group was 105 days as compared with more than 8 months for the controls. The 8000-r dose produced immediate immobilization with subsequent development of sluggish movement. No food was takenmore » and longest surviva) time was 33 days. After 10,000 r all movement stopped, all deaths occurring before 17 days. After 11,500 r there was no survival beyond 7 days. The survival time for a control group of 100 scorpions was over 6 months in spite of the high mortality figure for these arachnids in captivity. The results indicate a very high vulnerability in scorpions of this species to gamma radiation as compared with arthropods of the class Insecta, which appear to show a much greater resistance. (BBB)« less

Arthropod-borne diseases in Italy: from a neglected matter to an emerging health problem.

PubMed

Romi, Roberto

2010-01-01

In medical entomology, "Arthropod Borne Diseases", or "Vector Borne Diseases" (VBD) are intended as a group of human and animal infections caused by different pathogen organisms (protozoa, helminths, bacteria and viruses) transmitted by the bite of a bloodsucking insect or arachnid. It is commonly known that the infectious diseases transmitted by Arthropods are mainly affecting tropical and subtropical countries, nevertheless some of them were or are still common also in the northern hemisphere, where they are usually maintained under control. VBD still represent some of the most important public health problems in the endemic areas but are becoming source of concern for developed countries too. Since the last decades of the past century, a number of VBD has been spreading geographically, being recorded for the first time in areas outside their original range. This phenomenon is strictly related to the peculiar epidemiological characteristics of these diseases, that are considered the most susceptible to climatic, environmental and socioeconomic changes. This article is a short overview of the VBD endemic and emerging in Italy. The possibility that some exotic vectors and/or pathogens could be introduced and become established in Italy is also discussed.

Genomic resources and draft assemblies of the human and porcine varieties of scabies mites, Sarcoptes scabiei var. hominis and var. suis.

PubMed

Mofiz, Ehtesham; Holt, Deborah C; Seemann, Torsten; Currie, Bart J; Fischer, Katja; Papenfuss, Anthony T

2016-06-02

The scabies mite, Sarcoptes scabiei, is a parasitic arachnid and cause of the infectious skin disease scabies in humans and mange in other animal species. Scabies infections are a major health problem, particularly in remote Indigenous communities in Australia, where secondary group A streptococcal and Staphylococcus aureus infections of scabies sores are thought to drive the high rate of rheumatic heart disease and chronic kidney disease. We sequenced the genome of two samples of Sarcoptes scabiei var. hominis obtained from unrelated patients with crusted scabies located in different parts of northern Australia using the Illumina HiSeq. We also sequenced samples of Sarcoptes scabiei var. suis from a pig model. Because of the small size of the scabies mite, these data are derived from pools of thousands of mites and are metagenomic, including host and microbiome DNA. We performed cleaning and de novo assembly and present Sarcoptes scabiei var. hominis and var. suis draft reference genomes. We have constructed a preliminary annotation of this reference comprising 13,226 putative coding sequences based on sequence similarity to known proteins. We have developed extensive genomic resources for the scabies mite, including reference genomes and a preliminary annotation.

The role of viral persistence in flavivirus biology

PubMed Central

Mlera, Luwanika; Melik, Wessam; Bloom, Marshall E.

2014-01-01

In nature, vector-borne flaviviruses are persistently cycled between either the tick or mosquito vector and small mammals such as rodents, skunks, and swine. These viruses account for considerable human morbidity and mortality worldwide. Increasing and substantial evidence of viral persistence in humans, which includes the isolation of RNA by RT-PCR and infectious virus by culture, continues to be reported. Viral persistence can also be established in vitro in various human, animal, arachnid and insect cell lines in culture. Although some research has focused on the potential roles of defective virus particles, evasion of the immune response through the manipulation of autophagy and/or apoptosis, the precise mechanism of flavivirus persistence is still not well understood. We propose additional research for further understanding of how viral persistence is established in different systems. Avenues for additional studies include determining if the multifunctional flavivirus protein NS5 has a role in viral persistence, the development of relevant animal models of viral persistence as well as investigating the host responses that allow vector borne flavivirus replication without detrimental effects on infected cells. Such studies might shed more light on the viral-host relationships, and could be used to unravel the mechanisms for establishment of persistence. PMID:24737600

The embryonic origin of the ampullate silk glands of the spider Cupiennius salei.

PubMed

Hilbrant, Maarten; Damen, Wim G M

2015-05-01

Silk production in spiders is considered a key innovation, and to have been vital for the diversification of the clade. The evolutionary origin of the organs involved in spider silk production, however, and in particular of the silk glands, is poorly understood. Homologies have been proposed between these and other glands found in arachnids, but lacking knowledge of the embryonic development of spider silk glands hampers an evaluation of hypotheses. This study focuses on the embryonic origin of the largest silk glands of the spider Cupiennius salei, the major and minor ampullate glands. We show how the ampullate glands originate from ectodermal invaginations on the embryonic spinneret limb buds, in relation to morphogenesis of these buds. Moreover, we visualize the subsequent growth of the ampullate glands in sections of the early postembryonic stages. The invaginations are shown to correlate with expression of the proneural gene CsASH2, which is remarkable since it has been proposed that spider silk glands and their nozzles originate from sensory bristles. Hence, by confirming the ectodermal origin of spider silk glands, and by describing the (post-)embryonic morphogenesis of the ampullate glands, this work provides a starting point for further investigating into the genetic program that underlies their development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quo Vadis Venomics? A Roadmap to Neglected Venomous Invertebrates

PubMed Central

von Reumont, Bjoern Marcus; Campbell, Lahcen I.; Jenner, Ronald A.

2014-01-01

Venomics research is being revolutionized by the increased use of sensitive -omics techniques to identify venom toxins and their transcripts in both well studied and neglected venomous taxa. The study of neglected venomous taxa is necessary both for understanding the full diversity of venom systems that have evolved in the animal kingdom, and to robustly answer fundamental questions about the biology and evolution of venoms without the distorting effect that can result from the current bias introduced by some heavily studied taxa. In this review we draw the outlines of a roadmap into the diversity of poorly studied and understood venomous and putatively venomous invertebrates, which together represent tens of thousands of unique venoms. The main groups we discuss are crustaceans, flies, centipedes, non-spider and non-scorpion arachnids, annelids, molluscs, platyhelminths, nemerteans, and echinoderms. We review what is known about the morphology of the venom systems in these groups, the composition of their venoms, and the bioactivities of the venoms to provide researchers with an entry into a large and scattered literature. We conclude with a short discussion of some important methodological aspects that have come to light with the recent use of new -omics techniques in the study of venoms. PMID:25533518

Extant primitively segmented spiders have recently diversified from an ancient lineage

PubMed Central

Xu, Xin; Liu, Fengxiang; Cheng, Ren-Chung; Chen, Jian; Xu, Xiang; Zhang, Zhisheng; Ono, Hirotsugu; Pham, Dinh Sac; Norma-Rashid, Y.; Arnedo, Miquel A.; Kuntner, Matjaž; Li, Daiqin

2015-01-01

Living fossils are lineages that have retained plesiomorphic traits through long time periods. It is expected that such lineages have both originated and diversified long ago. Such expectations have recently been challenged in some textbook examples of living fossils, notably in extant cycads and coelacanths. Using a phylogenetic approach, we tested the patterns of the origin and diversification of liphistiid spiders, a clade of spiders considered to be living fossils due to their retention of arachnid plesiomorphies and their exclusive grouping in Mesothelae, an ancient clade sister to all modern spiders. Facilitated by original sampling throughout their Asian range, we here provide the phylogenetic framework necessary for reconstructing liphistiid biogeographic history. All phylogenetic analyses support the monophyly of Liphistiidae and of eight genera. As the fossil evidence supports a Carboniferous Euramerican origin of Mesothelae, our dating analyses postulate a long eastward over-land dispersal towards the Asian origin of Liphistiidae during the Palaeogene (39–58 Ma). Contrary to expectations, diversification within extant liphistiid genera is relatively recent, in the Neogene and Late Palaeogene (4–24 Ma). While no over-water dispersal events are needed to explain their evolutionary history, the history of liphistiid spiders has the potential to play prominently in vicariant biogeographic studies. PMID:25948684

Impact of pest control strategies on the arthropodofauna living in bird nests built in nestboxes in pear and apple orchards.

PubMed

Roy, Lise; Bouvier, Jean-Charles; Lavigne, Claire; Galès, Mathieu; Buronfosse, Thierry

2013-08-01

Pesticide applications have a strong impact on biodiversity in agroecosystems. The present study aimed to assess the impact of pest control strategies on the arthropodofauna of Parus major nests built within nestboxes installed in orchards. Unlike many studied groups, these arthropod communities are not in direct contact with pesticide sprays (on account of their being sheltered by nestboxes) and are also unable to move away from the treated area. In this pilot study, we estimated the prevalence and the taxonomic and ecological diversities of arthropodofauna sampled in the nests and assessed the extent to which the whole and nest-specific arthropodofauna were affected by pest control strategies. Sixteen different insect and arachnid Primary Taxonomic Groups (PTGs, order level or below) were found in nests. The best represented PTGs (≥10% occurrence in years 2007 and 2008) were Psocoptera (Insecta, detritivorous/saprophagous), detritivorous/saprophagous Astigmata (Acari) and hematophagous Mesostigmata (Acari). Pest control strategies had a large impact on the prevalence of arthropods in nests, with higher proportions of nests hosting arthropods in organic orchards than in conventional orchards and with intermediate proportions in nests in Integrated Pest Management orchards. In contrast, pest control strategies had no significant effect on the composition of the arthropod communities when only nests hosting nidicolous arthropods were considered.

Plastron Respiration Using Commercial Fabrics

PubMed Central

Atherton, Shaun; Brennan, Joseph C.; Morris, Robert H.; Smith, Joshua D.E.; Hamlett, Christopher A.E.; McHale, Glen; Shirtcliffe, Neil J.; Newton, Michael I.

2014-01-01

A variety of insect and arachnid species are able to remain submerged in water indefinitely using plastron respiration. A plastron is a surface-retained film of air produced by surface morphology that acts as an oxygen-carbon dioxide exchange surface. Many highly water repellent and hydrophobic surfaces when placed in water exhibit a silvery sheen which is characteristic of a plastron. In this article, the hydrophobicity of a range of commercially available water repellent fabrics and polymer membranes is investigated, and how the surface of the materials mimics this mechanism of underwater respiration is demonstrated allowing direct extraction of oxygen from oxygenated water. The coverage of the surface with the plastron air layer was measured using confocal microscopy. A zinc/oxygen cell is used to consume oxygen within containers constructed from the different membranes, and the oxygen consumed by the cell is compared to the change in oxygen concentration as measured by an oxygen probe. By comparing the membranes to an air-tight reference sample, it was found that the membranes facilitated oxygen transfer from the water into the container, with the most successful membrane showing a 1.90:1 ratio between the cell oxygen consumption and the change in concentration within the container. PMID:28788469

Insights into the Hypertensive Effects of Tityus serrulatus Scorpion Venom: Purification of an Angiotensin-Converting Enzyme-Like Peptidase.

PubMed

Cajado-Carvalho, Daniela; Kuniyoshi, Alexandre Kazuo; Duzzi, Bruno; Iwai, Leo Kei; Oliveira, Úrsula Castro de; Junqueira de Azevedo, Inácio de Loiola Meirelles; Kodama, Roberto Tadashi; Portaro, Fernanda Vieira

2016-11-24

The number of cases of envenomation by scorpions has grown significantly in Brazil since 2007, with the most severe cases being caused by the Tityus serrulatus scorpion. Although envenomed patients mostly suffer neurotoxic manifestations, other symptoms, such as hypertension, cannot be exclusively attributed to neurotoxins. Omics analyses have detected plentiful amounts of metalloproteases in T. serrulatus venom. However, the roles played by these enzymes in envenomation are still unclear. Endeavoring to investigate the functions of scorpion venom proteases, we describe here for the first time an Angiotensin I-Converting Enzyme-like peptidase (ACE-like) purified from T. serrulatus venom. The crude venom cleaved natural and fluorescent substrates and these activities were inhibited by captopril. Regarding the serum neutralization, the scorpion antivenom was more effective at blocking the ACE-like activity than arachnid antivenom, although neither completely inhibited the venom cleavage action, even at higher doses. ACE-like was purified from the venom after three chromatographic steps and its identity was confirmed by mass spectrometric and transcriptomic analyses. Bioinformatics analysis showed homology between the ACE-like transcript sequences from Tityus spp. and human testis ACE. These findings advance our understanding of T. serrulatus venom components and may improve treatment of envenomation victims, as ACE-like may contribute to envenomation symptoms, especially the resulting hypertension.

Insights into the Hypertensive Effects of Tityus serrulatus Scorpion Venom: Purification of an Angiotensin-Converting Enzyme-Like Peptidase

PubMed Central

Cajado-Carvalho, Daniela; Kuniyoshi, Alexandre Kazuo; Duzzi, Bruno; Iwai, Leo Kei; de Oliveira, Úrsula Castro; Junqueira de Azevedo, Inácio de Loiola Meirelles; Kodama, Roberto Tadashi; Portaro, Fernanda Vieira

2016-01-01

The number of cases of envenomation by scorpions has grown significantly in Brazil since 2007, with the most severe cases being caused by the Tityus serrulatus scorpion. Although envenomed patients mostly suffer neurotoxic manifestations, other symptoms, such as hypertension, cannot be exclusively attributed to neurotoxins. Omics analyses have detected plentiful amounts of metalloproteases in T. serrulatus venom. However, the roles played by these enzymes in envenomation are still unclear. Endeavoring to investigate the functions of scorpion venom proteases, we describe here for the first time an Angiotensin I-Converting Enzyme-like peptidase (ACE-like) purified from T. serrulatus venom. The crude venom cleaved natural and fluorescent substrates and these activities were inhibited by captopril. Regarding the serum neutralization, the scorpion antivenom was more effective at blocking the ACE-like activity than arachnid antivenom, although neither completely inhibited the venom cleavage action, even at higher doses. ACE-like was purified from the venom after three chromatographic steps and its identity was confirmed by mass spectrometric and transcriptomic analyses. Bioinformatics analysis showed homology between the ACE-like transcript sequences from Tityus spp. and human testis ACE. These findings advance our understanding of T. serrulatus venom components and may improve treatment of envenomation victims, as ACE-like may contribute to envenomation symptoms, especially the resulting hypertension. PMID:27886129

Discovering the silk road: Nuclear and mitochondrial sequence data resolve the phylogenetic relationships among theraphosid spider subfamilies.

PubMed

Lüddecke, Tim; Krehenwinkel, Henrik; Canning, Gregory; Glaw, Frank; Longhorn, Stuart J; Tänzler, René; Wendt, Ingo; Vences, Miguel

2018-02-01

The mygalomorph spiders in the family Theraphosidae, also known as "tarantulas", are one of the most popular and diverse groups of arachnids, but their evolutionary history remains poorly understood because morphological analyses have only provided mostly controversial results, and a broad molecular perspective has been lacking until now. In this study we provide a preliminary molecular phylogenetic hypothesis of relationships among theraphosid subfamilies, based on 3.5 kbp of three nuclear and three mitochondrial markers, for 52 taxa representing 10 of the 11 commonly accepted subfamilies. Our analysis confirms the monophyly of the Theraphosidae and of most recognized theraphosid subfamilies, supports the validity of the Stromatopelminae and Poecilotheriinae, and indicates paraphyly of the Schismatothelinae. The placement of representatives of Schismatothelinae also indicates possible non-monophyly of Aviculariinae and supports the distinction of the previously contentious subfamily Psalmopoeinae. Major clades typically corresponded to taxa occurring in the same biogeographic region, with two of them each occurring in Africa, South America and Asia. Because relationships among these major clades were poorly supported, more extensive molecular data sets are required to test the hypothesis of independent colonization and multiple dispersal events among these continents. Copyright © 2017 Elsevier Inc. All rights reserved.

Hox gene duplications correlate with posterior heteronomy in scorpions

PubMed Central

Sharma, Prashant P.; Schwager, Evelyn E.; Extavour, Cassandra G.; Wheeler, Ward C.

2014-01-01

The evolutionary success of the largest animal phylum, Arthropoda, has been attributed to tagmatization, the coordinated evolution of adjacent metameres to form morphologically and functionally distinct segmental regions called tagmata. Specification of regional identity is regulated by the Hox genes, of which 10 are inferred to be present in the ancestor of arthropods. With six different posterior segmental identities divided into two tagmata, the bauplan of scorpions is the most heteronomous within Chelicerata. Expression domains of the anterior eight Hox genes are conserved in previously surveyed chelicerates, but it is unknown how Hox genes regionalize the three tagmata of scorpions. Here, we show that the scorpion Centruroides sculpturatus has two paralogues of all Hox genes except Hox3, suggesting cluster and/or whole genome duplication in this arachnid order. Embryonic anterior expression domain boundaries of each of the last four pairs of Hox genes (two paralogues each of Antp, Ubx, abd-A and Abd-B) are unique and distinguish segmental groups, such as pectines, book lungs and the characteristic tail, while maintaining spatial collinearity. These distinct expression domains suggest neofunctionalization of Hox gene paralogues subsequent to duplication. Our data reconcile previous understanding of Hox gene function across arthropods with the extreme heteronomy of scorpions. PMID:25122224

Male dimorphism and alternative reproductive tactics in harvestmen (Arachnida: Opiliones).

PubMed

Buzatto, Bruno A; Machado, Glauco

2014-11-01

Strong sexual selection may lead small males or males in poor condition to adopt alternative reproductive tactics (ARTs) as a way to avoid the risk of being completely excluded from the mating pool. ARTs, sometimes accompanying morphological dimorphism among males, are taxonomically widespread, especially common in arthropods. Here we review the current knowledge on ARTs and male dimorphism in a diverse but relatively overlooked group of arachnids, the order Opiliones, popularly known as harvestmen or daddy long-legs. We begin with a summary of harvestman mating systems, followed by a review of the two lines of evidence for the presence of ARTs in the group: (1) morphological data from natural populations and museum collections; and (2) behavioral information from field studies. Despite receiving less attention than spiders, scorpions and insects, our review shows that harvestmen are an exciting group of organisms that are potentially great models for sexual selection studies focused on ARTs. We also suggest that investigating the proximate mechanisms underlying male dimorphism in the order would be especially important. New research on ARTs and male dimorphism will have implications for our understanding of the evolution of mating systems, sperm competition, and polyandry. This article is part of a Special Issue entitled: Neotropical Behaviour. Copyright © 2014 Elsevier B.V. All rights reserved.

Sexually dimorphic venom proteins in long-jawed orb-weaving spiders (Tetragnatha) comprise novel gene families

PubMed Central

Zobel-Thropp, Pamela A.; Bulger, Emily A.; Cordes, Matthew H.J.; Binford, Greta J.; Gillespie, Rosemary G.

2018-01-01

Venom has been associated with the ecological success of many groups of organisms, most notably reptiles, gastropods, and arachnids. In some cases, diversification has been directly linked to tailoring of venoms for dietary specialization. Spiders in particular are known for their diverse venoms and wide range of predatory behaviors, although there is much to learn about scales of variation in venom composition and function. The current study focuses on venom characteristics in different sexes within a species of spider. We chose the genus Tetragnatha (Tetragnathidae) because of its unusual courtship behavior involving interlocking of the venom delivering chelicerae (i.e., the jaws), and several species in the genus are already known to have sexually dimorphic venoms. Here, we use transcriptome and proteome analyses to identify venom components that are dimorphic in Tetragnatha versicolor. We present cDNA sequences including unique, male-specific high molecular weight proteins that have remote, if any, detectable similarity to known venom components in spiders or other venomous lineages and have no detectable homologs in existing databases. While the function of these proteins is not known, their presence in association with the cheliceral locking mechanism during mating together with the presence of prolonged male-male mating attempts in a related, cheliceral-locking species (Doryonychus raptor) lacking the dimorphism suggests potential for a role in sexual communication. PMID:29876146

Conservation status of Chinese species: (2) Invertebrates.

PubMed

Xie, Yan; Wang, Sung

2007-06-01

A total of 2441 invertebrate species were evaluated using the IUCN Red List Criteria and Regional Guidelines. Approximately 30 experts were involved in this project, which covered a wide range of species, including jellyfish, corals, planarians, snails, mollusks, bivalves, decapods, benthic crustaceans, arachnids (spiders, scorpions), butterflies, moths, beetles, sea cucumbers, sea urchins, sea stars, acorn worms and lancelets. In general, invertebrate species in China were found to be severely threatened, with 0.9% being critically endangered, 13.44% endangered and 20.63% vulnerable. All species of hermatypic corals and planarians are threatened. More than 80% of evaluated species face serious threat due to habitat destruction by coral collection, logging, non-woody vegetation collection, timber plantations, non-timber plantations, extraction and/or livestock. Other threats are intrinsic factors, harvesting by humans, alien invasive species and pollution. The main intrinsic factors contributing to the high levels of threat are limited dispersal and restricted range. No conservation measures have been taken for 70% of the threatened invertebrates evaluated. Existing conservation measures include: strengthening of national and international legislation (Convention on International Trade in Endangered Species of Wild Fauna and Flora), increasing public awareness, studying population trends/monitoring, and establishment of protected areas. The major conservation measure employed is strengthening of policies. Relative to the situation worldwide (2006 IUCN Red List), there is little information available about invertebrate extinctions in China.

Phylogeography of the Cactophilic Drosophila and Other Arthropods Associated with Cactus Necroses in the Sonoran Desert

PubMed Central

Pfeiler, Edward; Markow, Therese A.

2011-01-01

Studies on the population genetics, phylogenetic relationships, systematics and evolution of arthropods that inhabit necrotic tissue of cacti in the Sonoran Desert of North America are reviewed. These studies have focused upon several species of insects (orders Diptera and Coleoptera) and arachnids (order Pseudoscorpiones). For most taxa studied, little genetic structure and high dispersal ability are found in populations inhabiting the mainland and Baja California peninsula regions of the Sonoran Desert, consistent with the availability of the rotting cactus microhabitat which is patchily distributed and ephemeral. There is evidence, however, that the Gulf of California, which bisects the Sonoran Desert, has played a role in limiting gene flow and promoting speciation in several taxa, including histerid beetles, whereas other taxa, especially Drosophila nigrospiracula and D. mettleri, apparently are able to freely cross the Gulf, probably by taking advantage of the Midriff Islands in the northern Gulf as dispersal “stepping stones”. Genetic evidence has also been found for historical population expansions dating to the Pleistocene and late Pliocene in several taxa. Overall, these studies have provided important insights into how arthropods with different life history traits, but generally restricted to a necrotic cactus microhabitat, have evolved in an environmentally harsh and tectonically active region. In addition, they suggest some taxa for further, and more detailed, hypothesis driven studies of speciation. PMID:26467624

A wolf in sheep's clothing: The description of a fly resembling jumping spider of the genus Scoturius Simon, 1901 (Araneae: Salticidae: Huriini).

PubMed

Perger, Robert; Rubio, Gonzalo D

2018-01-01

Fly resemblance in arthropods is much less common than e.g., resemblance to ants or wasps, and has been mainly observed in beetles. Putative fly mimicry in arachnids has been reported only from the jumping spider genus Saitis. However, recent literature has attributed the fly-resembling characteristics in Saitis to sexual signalling during courtship. The lack of observation of fly mimicry in spiders is not surprising as flies belong to the most important prey item group of spiders. In this study, a new fly-resembling species of the jumping spider tribe Huriini, Scoturius dipterioides sp. nov., from the pre-Andean Chiquitano forest at the Bolivian orocline is described and illustrated. The new species was tentatively placed into Scoturius because the epigynum has a single large elliptical opening. Scoturius dipterioides sp. nov. is distinguished from all other species of this tribe by a combination of following characteristics: epigynum with a large anterior elliptical atrium and initial portion of the copulation ducts dilated as a chamber (shared with Urupuyu); relatively joined copulation openings and short copulation ducts; kidney-shaped spermathecae, advanced at the atrium level. Several somatic features, two of them found exclusively in S. dipterioides sp. nov., increase the resemblance to flies. The Huriini are currently the only spider tribe that is suggested to feature fly mimics.

Spider Transcriptomes Identify Ancient Large-Scale Gene Duplication Event Potentially Important in Silk Gland Evolution

PubMed Central

Clarke, Thomas H.; Garb, Jessica E.; Hayashi, Cheryl Y.; Arensburger, Peter; Ayoub, Nadia A.

2015-01-01

The evolution of specialized tissues with novel functions, such as the silk synthesizing glands in spiders, is likely an influential driver of adaptive success. Large-scale gene duplication events and subsequent paralog divergence are thought to be required for generating evolutionary novelty. Such an event has been proposed for spiders, but not tested. We de novo assembled transcriptomes from three cobweb weaving spider species. Based on phylogenetic analyses of gene families with representatives from each of the three species, we found numerous duplication events indicative of a whole genome or segmental duplication. We estimated the age of the gene duplications relative to several speciation events within spiders and arachnids and found that the duplications likely occurred after the divergence of scorpions (order Scorpionida) and spiders (order Araneae), but before the divergence of the spider suborders Mygalomorphae and Araneomorphae, near the evolutionary origin of spider silk glands. Transcripts that are expressed exclusively or primarily within black widow silk glands are more likely to have a paralog descended from the ancient duplication event and have elevated amino acid replacement rates compared with other transcripts. Thus, an ancient large-scale gene duplication event within the spider lineage was likely an important source of molecular novelty during the evolution of silk gland-specific expression. This duplication event may have provided genetic material for subsequent silk gland diversification in the true spiders (Araneomorphae). PMID:26058392

Hemocyanin gene family evolution in spiders (Araneae), with implications for phylogenetic relationships and divergence times in the infraorder Mygalomorphae.

PubMed

Starrett, James; Hedin, Marshal; Ayoub, Nadia; Hayashi, Cheryl Y

2013-07-25

Hemocyanins are multimeric copper-containing hemolymph proteins involved in oxygen binding and transport in all major arthropod lineages. Most arachnids have seven primary subunits (encoded by paralogous genes a-g), which combine to form a 24-mer (4×6) quaternary structure. Within some spider lineages, however, hemocyanin evolution has been a dynamic process with extensive paralog duplication and loss. We have obtained hemocyanin gene sequences from numerous representatives of the spider infraorders Mygalomorphae and Araneomorphae in order to infer the evolution of the hemocyanin gene family and estimate spider relationships using these conserved loci. Our hemocyanin gene tree is largely consistent with the previous hypotheses of paralog relationships based on immunological studies, but reveals some discrepancies in which paralog types have been lost or duplicated in specific spider lineages. Analyses of concatenated hemocyanin sequences resolved deep nodes in the spider phylogeny and recovered a number of clades that are supported by other molecular studies, particularly for mygalomorph taxa. The concatenated data set is also used to estimate dates of higher-level spider divergences and suggests that the diversification of extant mygalomorphs preceded that of extant araneomorphs. Spiders are diverse in behavior and respiratory morphology, and our results are beneficial for comparative analyses of spider respiration. Lastly, the conserved hemocyanin sequences allow for the inference of spider relationships and ancient divergence dates. Copyright © 2013 Elsevier B.V. All rights reserved.

Age and size at maturity: a quantitative review of diet-induced reaction norms in insects.

PubMed

Teder, Tiit; Vellau, Helen; Tammaru, Toomas

2014-11-01

Optimality models predict that diet-induced bivariate reaction norms for age and size at maturity can have diverse shapes, with the slope varying from negative to positive. To evaluate these predictions, we perform a quantitative review of relevant data, using a literature-derived database of body sizes and development times for over 200 insect species. We show that bivariate reaction norms with a negative slope prevail in nearly all taxonomic and ecological categories of insects as well as in some other ectotherm taxa with comparable life histories (arachnids and amphibians). In insects, positive slopes are largely limited to species, which feed on discrete resource items, parasitoids in particular. By contrast, with virtually no meaningful exceptions, herbivorous and predatory insects display reaction norms with a negative slope. This is consistent with the idea that predictable resource depletion, a scenario selecting for positively sloped reaction norms, is not frequent for these insects. Another source of such selection-a positive correlation between resource levels and juvenile mortality rates-should similarly be rare among insects. Positive slopes can also be predicted by models which integrate life-history evolution and population dynamics. As bottom-up regulation is not common in most insect groups, such models may not be most appropriate for insects. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

Fish and shellfish allergy in children: review of a persistent food allergy.

PubMed

Tsabouri, Sophia; Triga, Maria; Makris, Michael; Kalogeromitros, Dimitris; Church, Martin K; Priftis, Kostas N

2012-11-01

The increased consumption of fish and shellfish has resulted in more frequent reports of adverse reactions to seafood, emphasizing the need for more specific diagnosis and treatment of this condition and exploring reasons for the persistence of this allergy. This review discusses interesting and new findings in the area of fish and shellfish allergy. New allergens and important potential cross-reacting allergens have been identified within the fish family and between shellfish, arachnids, and insects. The diagnostic approach may require prick to-prick tests using crude extracts of both raw and cooked forms of seafood for screening seafood sensitization before a food challenge or where food challenge is not feasible. Allergen-specific immunotherapy can be important; mutated less allergenic seafood proteins have been developed for this purpose. The persistence of allergy because of seafood proteins' resistance after rigorous treatment like cooking and extreme pH is well documented. Additionally, IgE antibodies from individuals with persistent allergy may be directed against different epitopes than those in patients with transient allergy. For a topic as important as this one, new areas of technological developments will likely have a significant impact, to provide more accurate methods of diagnosing useful information to patients about the likely course of their seafood allergy over the course of their childhood and beyond. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

An annotated type catalogue of the camel spiders (Arachnida: Solifugae) held in the Zoological Museum Hamburg.

PubMed

Harms, Danilo; DupÉrrÉ, Nadine

2018-01-23

Solifuges are an enigmatic and poorly studied group of arachnids. Commonly referred to as camel spiders or sun spiders, these animals are voracious predators of small animals and found in arid biomes of the Old World and the Americas. In this paper, we provide a catalogue for the solifuges (Arachnida: Solifugae) that are held at the Center of Natural History in Hamburg. The collections in Hamburg are predominantly historical and were accumulated by Karl Kraepelin between 1889 and 1914 with the help of other famous arachnologists such as Ferdinant Karsch and Eugène Simon. The re-study of these collections indicates that there are 38 type species and 65 type specimens from 10 families. We provide a detailed account of this material, including collection data, taxonomic updates, measurements and high-resolution images for species that are either poorly or not at all illustrated. Most specimens (70%) were collected in Africa as part of colonial expeditions or field surveys but there are also types from Western Asia (11%), and North and South America (19%). We provide an overview of the history of this collection, including a summary of the field surveys during which the specimens were collected and the arachnologists who described the material. Overall, this is the third-largest collection of solifuges in Germany with a distinct biogeographical focus and one of the largest collections of camel spiders in Europe.

Phylogeography of the Cactophilic Drosophila and Other Arthropods Associated with Cactus Necroses in the Sonoran Desert.

PubMed

Pfeiler, Edward; Markow, Therese A

2011-05-05

Studies on the population genetics, phylogenetic relationships, systematics and evolution of arthropods that inhabit necrotic tissue of cacti in the Sonoran Desert of North America are reviewed. These studies have focused upon several species of insects (orders Diptera and Coleoptera) and arachnids (order Pseudoscorpiones). For most taxa studied, little genetic structure and high dispersal ability are found in populations inhabiting the mainland and Baja California peninsula regions of the Sonoran Desert, consistent with the availability of the rotting cactus microhabitat which is patchily distributed and ephemeral. There is evidence, however, that the Gulf of California, which bisects the Sonoran Desert, has played a role in limiting gene flow and promoting speciation in several taxa, including histerid beetles, whereas other taxa, especially Drosophila nigrospiracula and D. mettleri, apparently are able to freely cross the Gulf, probably by taking advantage of the Midriff Islands in the northern Gulf as dispersal "stepping stones". Genetic evidence has also been found for historical population expansions dating to the Pleistocene and late Pliocene in several taxa. Overall, these studies have provided important insights into how arthropods with different life history traits, but generally restricted to a necrotic cactus microhabitat, have evolved in an environmentally harsh and tectonically active region. In addition, they suggest some taxa for further, and more detailed, hypothesis driven studies of speciation.

Ecological importance of sedges: a survey of the Australasian Cyperaceae genus Lepidosperma

PubMed Central

Barrett, Russell L.

2013-01-01

Background Sedges (Cyperaceae) form an important ecological component of many ecosystems around the world. Sword and rapier sedges (genus Lepidosperma) are common and widespread components of the southern Australian and New Zealand floras, also occurring in New Caledonia, West Papua, Borneo, Malaysia and southern China. Sedge ecology is seldom studied and no comprehensive review of sedge ecology exists. Lepidosperma is unusual in the Cyperaceae with the majority of species occurring in dryland habitats. Scope Extensive review of ecological literature and field observations shows Lepidosperma species to be important components of many ecosystems, often dominating understorey and sedge-rich communities. For the first time, a detailed ecological review of a Cyperaceae genus is presented. Conclusions Lepidosperma species are long-lived perennials with significant abundance and persistence in the landscape. Speciation patterns in the genus are of considerable interest due to complex biogeographical patterns and a high degree of habitat specificity. Potential benefits exist for medicinal products identified from several Lepidosperma species. Over 178 organisms, including 26 mammals, 42 birds, six reptiles, five amphibians, eight arachnids, 75 insects, three crustaceans and 13 fungi, are found to be dependent on, or making use of, Lepidosperma species. A significant relationship exists between Lepidosperma species and the moth genus Elachista. Implications for the conservation and ecology of both sedges and associated species are discussed. PMID:23378523

Extant primitively segmented spiders have recently diversified from an ancient lineage.

PubMed

Xu, Xin; Liu, Fengxiang; Cheng, Ren-Chung; Chen, Jian; Xu, Xiang; Zhang, Zhisheng; Ono, Hirotsugu; Pham, Dinh Sac; Norma-Rashid, Y; Arnedo, Miquel A; Kuntner, Matjaž; Li, Daiqin

2015-06-07

Living fossils are lineages that have retained plesiomorphic traits through long time periods. It is expected that such lineages have both originated and diversified long ago. Such expectations have recently been challenged in some textbook examples of living fossils, notably in extant cycads and coelacanths. Using a phylogenetic approach, we tested the patterns of the origin and diversification of liphistiid spiders, a clade of spiders considered to be living fossils due to their retention of arachnid plesiomorphies and their exclusive grouping in Mesothelae, an ancient clade sister to all modern spiders. Facilitated by original sampling throughout their Asian range, we here provide the phylogenetic framework necessary for reconstructing liphistiid biogeographic history. All phylogenetic analyses support the monophyly of Liphistiidae and of eight genera. As the fossil evidence supports a Carboniferous Euramerican origin of Mesothelae, our dating analyses postulate a long eastward over-land dispersal towards the Asian origin of Liphistiidae during the Palaeogene (39-58 Ma). Contrary to expectations, diversification within extant liphistiid genera is relatively recent, in the Neogene and Late Palaeogene (4-24 Ma). While no over-water dispersal events are needed to explain their evolutionary history, the history of liphistiid spiders has the potential to play prominently in vicariant biogeographic studies. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

A wolf in sheep’s clothing: The description of a fly resembling jumping spider of the genus Scoturius Simon, 1901 (Araneae: Salticidae: Huriini)

PubMed Central

Rubio, Gonzalo D.

2018-01-01

Fly resemblance in arthropods is much less common than e.g., resemblance to ants or wasps, and has been mainly observed in beetles. Putative fly mimicry in arachnids has been reported only from the jumping spider genus Saitis. However, recent literature has attributed the fly-resembling characteristics in Saitis to sexual signalling during courtship. The lack of observation of fly mimicry in spiders is not surprising as flies belong to the most important prey item group of spiders. In this study, a new fly-resembling species of the jumping spider tribe Huriini, Scoturius dipterioides sp. nov., from the pre-Andean Chiquitano forest at the Bolivian orocline is described and illustrated. The new species was tentatively placed into Scoturius because the epigynum has a single large elliptical opening. Scoturius dipterioides sp. nov. is distinguished from all other species of this tribe by a combination of following characteristics: epigynum with a large anterior elliptical atrium and initial portion of the copulation ducts dilated as a chamber (shared with Urupuyu); relatively joined copulation openings and short copulation ducts; kidney-shaped spermathecae, advanced at the atrium level. Several somatic features, two of them found exclusively in S. dipterioides sp. nov., increase the resemblance to flies. The Huriini are currently the only spider tribe that is suggested to feature fly mimics. PMID:29364905

Vector and Serologic Survey for Crimean-Congo Hemorrhagic Fever Virus in Poland.

PubMed

Bażanów, Barbara A; Pacoń, Jarosław; Gadzała, Łukasz; Frącka, Agnieszka; Welz, Mirosław; Paweska, Janusz

2017-07-01

In contrast to animals, Crimean-Congo hemorrhagic fever (CCHF) causes a severe disease in humans with a high mortality rate. The etiological agent, CCHF virus (CCHFV), can be transmitted by argasid and ixodid ticks, but arachnids of the genus Hyalomma, followed by Rhipicephalus and Dermacentor serve as the major vectors of this virus. The goal of the study was to assess the epidemiological situation of CCHFV infection in cattle in south-east Poland, and survey for potential tick vector species. A total of 592 bovine blood samples from animals located in the southernmost region in Poland were tested by IgG sandwich enzyme-linked immunosorbent assay. Ticks (n = 993) from south-east Poland were collected from dogs, cats, cattle, and horses and tested by RT-PCR. All 592 serum samples were negative for IgG antibodies to CCHFV. Of the ticks collected, 125 were Dermacentor reticulatus and 868 represented Ixodes ricinus, both species are regarded as potential vectors of CCHFV. All tick samples were negative for the presence of CCHFV. Considering the zoonotic nature, public health importance, and the virus increasing spread, it was prudent to assess the seroprevalence of CCHFV in the south-east area of Poland, bordering with CCHFV endemic areas. It seems unlikely that CCHFV infection will suddenly spread in Poland, but considering the multiple possibilities of the virus introduction, serosurveys and vector biosurveillance should be conducted at regular intervals.

Characterization of a Gene Coding for the Complement System Component FB from Loxosceles laeta Spider Venom Glands.

PubMed

Myamoto, Daniela Tiemi; Pidde-Queiroz, Giselle; Gonçalves-de-Andrade, Rute Maria; Pedroso, Aurélio; van den Berg, Carmen W; Tambourgi, Denise V

2016-01-01

The human complement system is composed of more than 30 proteins and many of these have conserved domains that allow tracing the phylogenetic evolution. The complement system seems to be initiated with the appearance of C3 and factor B (FB), the only components found in some protostomes and cnidarians, suggesting that the alternative pathway is the most ancient. Here, we present the characterization of an arachnid homologue of the human complement component FB from the spider Loxosceles laeta. This homologue, named Lox-FB, was identified from a total RNA L. laeta spider venom gland library and was amplified using RACE-PCR techniques and specific primers. Analysis of the deduced amino acid sequence and the domain structure showed significant similarity to the vertebrate and invertebrate FB/C2 family proteins. Lox-FB has a classical domain organization composed of a control complement protein domain (CCP), a von Willebrand Factor domain (vWFA), and a serine protease domain (SP). The amino acids involved in Mg2+ metal ion dependent adhesion site (MIDAS) found in the vWFA domain in the vertebrate C2/FB proteins are well conserved; however, the classic catalytic triad present in the serine protease domain is not conserved in Lox-FB. Similarity and phylogenetic analyses indicated that Lox-FB shares a major identity (43%) and has a close evolutionary relationship with the third isoform of FB-like protein (FB-3) from the jumping spider Hasarius adansoni belonging to the Family Salcitidae.

Characterization of a Gene Coding for the Complement System Component FB from Loxosceles laeta Spider Venom Glands

PubMed Central

Myamoto, Daniela Tiemi; Pidde-Queiroz, Giselle; Gonçalves-de-Andrade, Rute Maria; Pedroso, Aurélio; van den Berg, Carmen W.; Tambourgi, Denise V.

2016-01-01

The human complement system is composed of more than 30 proteins and many of these have conserved domains that allow tracing the phylogenetic evolution. The complement system seems to be initiated with the appearance of C3 and factor B (FB), the only components found in some protostomes and cnidarians, suggesting that the alternative pathway is the most ancient. Here, we present the characterization of an arachnid homologue of the human complement component FB from the spider Loxosceles laeta. This homologue, named Lox-FB, was identified from a total RNA L. laeta spider venom gland library and was amplified using RACE-PCR techniques and specific primers. Analysis of the deduced amino acid sequence and the domain structure showed significant similarity to the vertebrate and invertebrate FB/C2 family proteins. Lox-FB has a classical domain organization composed of a control complement protein domain (CCP), a von Willebrand Factor domain (vWFA), and a serine protease domain (SP). The amino acids involved in Mg2+ metal ion dependent adhesion site (MIDAS) found in the vWFA domain in the vertebrate C2/FB proteins are well conserved; however, the classic catalytic triad present in the serine protease domain is not conserved in Lox-FB. Similarity and phylogenetic analyses indicated that Lox-FB shares a major identity (43%) and has a close evolutionary relationship with the third isoform of FB-like protein (FB-3) from the jumping spider Hasarius adansoni belonging to the Family Salcitidae. PMID:26771533

Babes in the wood – a unique window into sea scorpion ontogeny

PubMed Central

2013-01-01

Background Few studies on eurypterids have taken into account morphological changes that occur throughout postembryonic development. Here two species of eurypterid are described from the Pragian Beartooth Butte Formation of Cottonwood Canyon in Wyoming and included in a phylogenetic analysis. Both species comprise individuals from a number of instars, and this allows for changes that occur throughout their ontogeny to be documented, and how ontogenetically variable characters can influence phylogenetic analysis to be tested. Results The two species of eurypterid are described as Jaekelopterus howelli (Kjellesvig-Waering and Størmer, 1952) and Strobilopterus proteus sp. nov. Phylogenetic analysis places them within the Pterygotidae and Strobilopteridae respectively, both families within the Eurypterina. Jaekelopterus howelli shows positive allometry of the cheliceral denticles throughout ontogeny, while a number of characteristics including prosomal appendage length, carapace shape, lateral eye position, and relative breadth all vary during the growth of Strobilopterus proteus. Conclusions The ontogeny of Strobilopterus proteus shares much in common with that of modern xiphosurans, however certain characteristics including apparent true direct development suggest a closer affinity to arachnids. The ontogenetic development of the genital appendage also supports the hypothesis that the structure is homologous to the endopods of the trunk limbs of other arthropods. Including earlier instars in the phylogenetic analysis is shown to destabilise the retrieved topology. Therefore, coding juveniles as individual taxa in an analysis is shown to be actively detrimental and alternative ways of coding ontogenetic data into phylogenetic analyses should be explored. PMID:23663507

Interaction of the tick immune system with transmitted pathogens

PubMed Central

Hajdušek, Ondřej; Šíma, Radek; Ayllón, Nieves; Jalovecká, Marie; Perner, Jan; de la Fuente, José; Kopáček, Petr

2013-01-01

Ticks are hematophagous arachnids transmitting a wide variety of pathogens including viruses, bacteria, and protozoans to their vertebrate hosts. The tick vector competence has to be intimately linked to the ability of transmitted pathogens to evade tick defense mechanisms encountered on their route through the tick body comprising midgut, hemolymph, salivary glands or ovaries. Tick innate immunity is, like in other invertebrates, based on an orchestrated action of humoral and cellular immune responses. The direct antimicrobial defense in ticks is accomplished by a variety of small molecules such as defensins, lysozymes or by tick-specific antimicrobial compounds such as microplusin/hebraein or 5.3-kDa family proteins. Phagocytosis of the invading microbes by tick hemocytes is likely mediated by the primordial complement-like system composed of thioester-containing proteins, fibrinogen-related lectins and convertase-like factors. Moreover, an important role in survival of the ingested microbes seems to be played by host proteins and redox balance maintenance in the tick midgut. Here, we summarize recent knowledge about the major components of tick immune system and focus on their interaction with the relevant tick-transmitted pathogens, represented by spirochetes (Borrelia), rickettsiae (Anaplasma), and protozoans (Babesia). Availability of the tick genomic database and feasibility of functional genomics based on RNA interference greatly contribute to the understanding of molecular and cellular interplay at the tick-pathogen interface and may provide new targets for blocking the transmission of tick pathogens. PMID:23875177

Clinical and Epidemiological Aspects of Scorpionism in the World: A Systematic Review.

PubMed

Santos, Maria S V; Silva, Cláudio G L; Neto, Basílio Silva; Grangeiro Júnior, Cícero R P; Lopes, Victor H G; Teixeira Júnior, Antônio G; Bezerra, Deryk A; Luna, João V C P; Cordeiro, Josué B; Júnior, Jucier Gonçalves; Lima, Marcos A P

2016-12-01

Scorpion stings are registered worldwide, but the incidence and the features of the envenomations vary depending on the region. The aim of this review was to summarize the epidemiological, clinical, diagnostic, and therapeutic data worldwide regarding humans stung by scorpions. A systematic review of the literature was conducted through the online databases of the Virtual Health Library (VHL), which hosts Medline and the Latin American and Caribbean Center on Health Sciences Informational (LILACS) database. We selected articles published between January 1, 2002 and July 31, 2014. Scorpion envenomation reports were found throughout the world, mainly in subtropical and tropical regions. The clinical manifestations were sympathetically and parasympathetically mediated, depending on the species of scorpion. Some of the most common severe complications of scorpionism included respiratory distress syndrome, pulmonary edema, cardiac dysfunction, impaired hemostasis, pancreatitis, and multiple organ failure. Scorpion envenomation could be classified as mild, moderate, and severe, and the therapeutic approach was based on the case severity. The treatment comprised 3 components: symptomatic measures, vital functions support, and injection of antivenom. Moreover, the time that elapsed between the sting and administration of the appropriate medical care was extremely important to the patient's prognosis. The large number of scorpion stings worldwide is concerning and reaffirms the need for new prevention measures and policies to reduce the incidence, prevalence, morbidity, and mortality rates from these poisonous arachnids. Copyright © 2016 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

CDM analysis

NASA Technical Reports Server (NTRS)

Larson, Robert E.; Mcentire, Paul L.; Oreilly, John G.

1993-01-01

The C Data Manager (CDM) is an advanced tool for creating an object-oriented database and for processing queries related to objects stored in that database. The CDM source code was purchased and will be modified over the course of the Arachnid project. In this report, the modified CDM is referred to as MCDM. Using MCDM, a detailed series of experiments was designed and conducted on a Sun Sparcstation. The primary results and analysis of the CDM experiment are provided in this report. The experiments involved creating the Long-form Faint Source Catalog (LFSC) database and then analyzing it with respect to following: (1) the relationships between the volume of data and the time required to create a database; (2) the storage requirements of the database files; and (3) the properties of query algorithms. The effort focused on defining, implementing, and analyzing seven experimental scenarios: (1) find all sources by right ascension--RA; (2) find all sources by declination--DEC; (3) find all sources in the right ascension interval--RA1, RA2; (4) find all sources in the declination interval--DEC1, DEC2; (5) find all sources in the rectangle defined by--RA1, RA2, DEC1, DEC2; (6) find all sources that meet certain compound conditions; and (7) analyze a variety of query algorithms. Throughout this document, the numerical results obtained from these scenarios are reported; conclusions are presented at the end of the document.

Effectiveness of two insect growth regulators against Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) and Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) and their impact on population densities of arthropod predators in cotton in Pakistan.

PubMed

Gogi, Muhammad D; Sarfraz, Rana M; Dosdall, Lloyd M; Arif, Muhammad J; Keddie, Andrew B; Ashfaq, Muhammad

2006-10-01

Field efficacies of two insect growth regulators (IGRs) at two recommended application rates, buprofezin at 370 and 555 g AI ha(-1) and lufenuron at 37 and 49 g AI ha(-1), were determined against the sweet potato whitefly, Bemisia tabaci (Gennadius), and the cotton bollworm, Helicoverpa armigera (Hübner), in experimental plots of cotton at the Directorate of Cotton Research, Faisalabad, Pakistan. Adverse effects of the IGRs on populations of associated arthropod predators, namely geocorids, chrysopids, coccinellids, formicids and arachnids, were also assessed. Both IGRs significantly reduced populations of B. tabaci at each application rate 24, 48 and 72 h after treatment, and higher doses were more effective than lower doses. Buprofezin was not effective against H. armigera at any tested dose for any time of treatment in any spray. Lufenuron applied at 37 and 49 g AI ha(-1) effectively suppressed H. armigera populations, resulting in significant reductions in crop damage. At lower doses, both IGRs appeared safe to predator populations, which did not differ significantly in IGR-treated versus untreated control plots. Population densities of formicids and coccinellids were significantly lower at high concentrations of both IGRs in treatment plots, possibly as a result of reduced prey availability. The potential role of buprofezin and lufenuron for control of B. tabaci and H. armigera in a spray programme and the likelihood of direct toxic effects of IGRs on predatory fauna of cotton are discussed.

The allometry of the arcuate body in the postembryonic development of the giant house spider Eratigena atrica.

PubMed

Napiórkowska, Teresa; Kobak, Jarosław

2018-03-10

The brain of arachnids contains a special neuropil area called the arcuate body (AB), whose function has been widely discussed. Its growth and proportion in the brain volume during postembryogenesis have been investigated only in several spider species. Our allometric study is aimed at determining to what extent the development of the AB in Eratigena atrica, a spider with unique biology and behaviour, is similar to the development of this body in other species. We put forward a hypothesis of allometric growth of this body in relation to the volume of the central nervous system (CNS) and its neuropil as well as in relation to the volume of the brain and its neuropil. The analysis of paraffin embedded, H + E stained histological preparations confirmed our hypothesis. The AB developed more slowly than the CNS and the neuropil of both the brain and the CNS. In contrast, it exhibited positive allometry in relation to the volume of the brain. This body increased more than nine times within the postembryonic development. Its proportion in the brain volume varied; the lowest was recorded in larvae and nymphs I; then, it increased in nymphs VI and decreased to 2.93% in nymphs X. We conclude that in Eratigena atrica, the AB develops differently that in orb-weaver and wandering spiders. There is no universal model of the AB development, although in adult spiders, regardless of their behaviour, the proportion of this area in the brain volume is similar.

Adaptations and Predispositions of Different Middle European Arthropod Taxa (Collembola, Araneae, Chilopoda, Diplopoda) to Flooding and Drought Conditions

PubMed Central

Marx, Michael Thomas; Guhmann, Patrick; Decker, Peter

2012-01-01

Simple Summary This review summarizes adaptations and predispositions of different arthropod taxa (springtails, web spiders, millipedes and centipedes) to flood and drought conditions. The main focus sis directed to arthropod species, which are living in Middle European floodplain forests and wetlands, because of the fast change of flood and drought conditions in these habitats. Furthermore the effects of the predicted regional climate change like increasing aperiodic summer flooding and decreasing winter and spring floods are also discussed. Abstract Floodplain forests and wetlands are amongst the most diverse and species rich habitats on earth. Arthropods are a key group for the high diversity pattern of these landscapes, due to the fact that the change between flooding and drought causes in different life cycles and in a variety of adaptations in the different taxa. The floodplain forests and wetlands of Central Amazonia are well investigated and over the last 50 years many adaptations of several hexapod, myriapod and arachnid orders were described. In contrast to Amazonia the Middle European floodplains were less investigated concerning the adaptations of arthropods to flood and drought conditions. This review summarizes the adaptations and predispositions of springtails, web spiders, millipedes and centipedes to the changeable flood and drought conditions of Middle European floodplain forests and wetlands. Furthermore the impact of regional climate change predictions like increasing aperiodic summer floods and the decrease of typical winter and spring floods are discussed in this article. PMID:26487164

The Opiliones tree of life: shedding light on harvestmen relationships through transcriptomics.

PubMed

Fernández, Rosa; Sharma, Prashant P; Tourinho, Ana Lúcia; Giribet, Gonzalo

2017-02-22

Opiliones are iconic arachnids with a Palaeozoic origin and a diversity that reflects ancient biogeographic patterns dating back at least to the times of Pangea. Owing to interest in harvestman diversity, evolution and biogeography, their relationships have been thoroughly studied using morphology and PCR-based Sanger approaches to infer their systematic relationships. More recently, two studies utilized transcriptomics-based phylogenomics to explore their basal relationships and diversification, but sampling was limiting for understanding deep evolutionary patterns, as they lacked good taxon representation at the family level. Here, we analysed a set of the 14 existing transcriptomes with 40 additional ones generated for this study, representing approximately 80% of the extant familial diversity in Opiliones. Our phylogenetic analyses, including a set of data matrices with different gene occupancy and evolutionary rates, and using a multitude of methods correcting for a diversity of factors affecting phylogenomic data matrices, provide a robust and stable Opiliones tree of life, where most families and higher taxa are precisely placed. Our dating analyses using alternative calibration points, methods and analytical parameters provide well-resolved old divergences, consistent with ancient regionalization in Pangea in some groups, and Pangean vicariance in others. The integration of state-of-the-art molecular techniques and analyses, together with the broadest taxonomic sampling to date presented in a phylogenomic study of harvestmen, provide new insights into harvestmen interrelationships, as well as an overview of the general biogeographic patterns of this ancient arthropod group. © 2017 The Author(s).

The Opiliones tree of life: shedding light on harvestmen relationships through transcriptomics

PubMed Central

Sharma, Prashant P.; Tourinho, Ana Lúcia

2017-01-01

Opiliones are iconic arachnids with a Palaeozoic origin and a diversity that reflects ancient biogeographic patterns dating back at least to the times of Pangea. Owing to interest in harvestman diversity, evolution and biogeography, their relationships have been thoroughly studied using morphology and PCR-based Sanger approaches to infer their systematic relationships. More recently, two studies utilized transcriptomics-based phylogenomics to explore their basal relationships and diversification, but sampling was limiting for understanding deep evolutionary patterns, as they lacked good taxon representation at the family level. Here, we analysed a set of the 14 existing transcriptomes with 40 additional ones generated for this study, representing approximately 80% of the extant familial diversity in Opiliones. Our phylogenetic analyses, including a set of data matrices with different gene occupancy and evolutionary rates, and using a multitude of methods correcting for a diversity of factors affecting phylogenomic data matrices, provide a robust and stable Opiliones tree of life, where most families and higher taxa are precisely placed. Our dating analyses using alternative calibration points, methods and analytical parameters provide well-resolved old divergences, consistent with ancient regionalization in Pangea in some groups, and Pangean vicariance in others. The integration of state-of-the-art molecular techniques and analyses, together with the broadest taxonomic sampling to date presented in a phylogenomic study of harvestmen, provide new insights into harvestmen interrelationships, as well as an overview of the general biogeographic patterns of this ancient arthropod group. PMID:28228511

The other prey-capture silk: Fibres made by glow-worms (Diptera: Keroplatidae) comprise cross-β-sheet crystallites in an abundant amorphous fraction.

PubMed

Walker, Andrew A; Weisman, Sarah; Trueman, Holly E; Merritt, David J; Sutherland, Tara D

2015-09-01

Glow-worms (larvae of dipteran genus Arachnocampa) are restricted to moist habitats where they capture flying prey using snares composed of highly extensible silk fibres and sticky mucus droplets. Little is known about the composition or structure of glow-worm snares, or the extent of possible convergence between glow-worm and arachnid capture silks. We characterised Arachnocampa richardsae silk and mucus using X-ray scattering, Fourier transform infrared spectroscopy and amino acid analysis. Silk but not mucus contained crystallites of the cross-β-sheet type, which occur in unrelated insect silks but have not been reported previously in fibres used for prey capture. Mucus proteins were rich in Gly (28.5%) and existed in predominantly a random coil structure, typical of many adhesive proteins. In contrast, the silk fibres were unusually rich in charged and polar residues, particularly Lys (18.1%), which we propose is related to their use in a highly hydrated state. Comparison of X-ray scattering, infrared spectroscopy and amino acid analysis data suggests that silk fibres contain a high fraction of disordered protein. We suggest that in the native hydrated state, silk fibres are capable of extension via deformation of both disordered regions and cross-β-sheet crystallites, and that high extensibility is an adaptation promoting successful prey capture. This study illustrates the rich variety of protein motifs that are available for recruitment into biopolymers, and how convergently evolved materials can nevertheless be based on fundamentally different protein structures. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Genome Sequencing of the Phytoseiid Predatory Mite Metaseiulus occidentalis Reveals Completely Atomized Hox Genes and Superdynamic Intron Evolution

PubMed Central

Hoy, Marjorie A.; Waterhouse, Robert M.; Wu, Ke; Estep, Alden S.; Ioannidis, Panagiotis; Palmer, William J.; Pomerantz, Aaron F.; Simão, Felipe A.; Thomas, Jainy; Jiggins, Francis M.; Murphy, Terence D.; Pritham, Ellen J.; Robertson, Hugh M.; Zdobnov, Evgeny M.; Gibbs, Richard A.; Richards, Stephen

2016-01-01

Metaseiulus occidentalis is an eyeless phytoseiid predatory mite employed for the biological control of agricultural pests including spider mites. Despite appearances, these predator and prey mites are separated by some 400 Myr of evolution and radically different lifestyles. We present a 152-Mb draft assembly of the M. occidentalis genome: Larger than that of its favored prey, Tetranychus urticae, but considerably smaller than those of many other chelicerates, enabling an extremely contiguous and complete assembly to be built—the best arachnid to date. Aided by transcriptome data, genome annotation cataloged 18,338 protein-coding genes and identified large numbers of Helitron transposable elements. Comparisons with other arthropods revealed a particularly dynamic and turbulent genomic evolutionary history. Its genes exhibit elevated molecular evolution, with strikingly high numbers of intron gains and losses, in stark contrast to the deer tick Ixodes scapularis. Uniquely among examined arthropods, this predatory mite’s Hox genes are completely atomized, dispersed across the genome, and it encodes five copies of the normally single-copy RNA processing Dicer-2 gene. Examining gene families linked to characteristic biological traits of this tiny predator provides initial insights into processes of sex determination, development, immune defense, and how it detects, disables, and digests its prey. As the first reference genome for the Phytoseiidae, and for any species with the rare sex determination system of parahaploidy, the genome of the western orchard predatory mite improves genomic sampling of chelicerates and provides invaluable new resources for functional genomic analyses of this family of agriculturally important mites. PMID:26951779

Spider Transcriptomes Identify Ancient Large-Scale Gene Duplication Event Potentially Important in Silk Gland Evolution.

PubMed

Clarke, Thomas H; Garb, Jessica E; Hayashi, Cheryl Y; Arensburger, Peter; Ayoub, Nadia A

2015-06-08

The evolution of specialized tissues with novel functions, such as the silk synthesizing glands in spiders, is likely an influential driver of adaptive success. Large-scale gene duplication events and subsequent paralog divergence are thought to be required for generating evolutionary novelty. Such an event has been proposed for spiders, but not tested. We de novo assembled transcriptomes from three cobweb weaving spider species. Based on phylogenetic analyses of gene families with representatives from each of the three species, we found numerous duplication events indicative of a whole genome or segmental duplication. We estimated the age of the gene duplications relative to several speciation events within spiders and arachnids and found that the duplications likely occurred after the divergence of scorpions (order Scorpionida) and spiders (order Araneae), but before the divergence of the spider suborders Mygalomorphae and Araneomorphae, near the evolutionary origin of spider silk glands. Transcripts that are expressed exclusively or primarily within black widow silk glands are more likely to have a paralog descended from the ancient duplication event and have elevated amino acid replacement rates compared with other transcripts. Thus, an ancient large-scale gene duplication event within the spider lineage was likely an important source of molecular novelty during the evolution of silk gland-specific expression. This duplication event may have provided genetic material for subsequent silk gland diversification in the true spiders (Araneomorphae). © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Ultrastructure of chemoreceptive tarsal sensilla in an armored harvestman and evidence of olfaction across Laniatores (Arachnida, Opiliones).

PubMed

Gainett, Guilherme; Michalik, Peter; Müller, Carsten H G; Giribet, Gonzalo; Talarico, Giovanni; Willemart, Rodrigo H

2017-03-01

Harvestmen (Arachnida, Opiliones) are especially dependent on chemical cues and are often regarded as animals that rely mainly on contact chemoreception. Information on harvestman sensilla is scarce when compared to other arachnid orders, especially concerning internal morphology. Using scanning (SEM) and transmission (TEM) electron microscopy, we investigated tarsal sensilla on the distal tarsomeres (DT) of all leg pairs in Heteromitobates discolor (Laniatores, Gonyleptidae). Furthermore, we explored the typological diversity of sensilla present on the DT I and II in members of the suborder Laniatores, which include two thirds of the formally described opilionid fauna, using species from 17 families representing all main laniatorian lineages. Our data revealed that DT I and II of H. discolor are equipped with wall-pored falciform hairs (two types), wall-pored sensilla chaetica (two types) and tip-pored sensilla chaetica, while DT III and IV are mainly covered with trichomes (non-sensory) and tip-pored sensilla chaetica. The ultrastructural characteristics support an olfactory function for all wall-pored sensilla and a dual gustatory/mechanoreceptive function for tip-pored sensilla chaetica. Based on our comparative SEM survey, we show that wall-pored sensilla occur in all investigated Laniatores, demonstrating their widespread occurrence in the suborder and highlighting the importance of both legs I and II as the sensory appendages of laniatorean harvestmen. Our results provide the first morphological evidence for olfactory receptors in Laniatores and suggest that olfaction is more important for harvestmen than previously thought. Copyright © 2016 Elsevier Ltd. All rights reserved.

Using Next-Generation Sequencing to Contrast the Diet and Explore Pest-Reduction Services of Sympatric Bird Species in Macadamia Orchards in Australia.

PubMed

Crisol-Martínez, Eduardo; Moreno-Moyano, Laura T; Wormington, Kevin R; Brown, Philip H; Stanley, Dragana

2016-01-01

Worldwide, avian communities inhabiting agro-ecosystems are threatened as a consequence of agricultural intensification. Unravelling their ecological role is essential to focus conservation efforts. Dietary analysis can elucidate bird-insect interactions and expose avian pest-reduction services, thus supporting avian conservation. In this study, we used next-generation sequencing to analyse the dietary arthropod contents of 11 sympatric bird species foraging in macadamia orchards in eastern Australia. Across all species and based on arthropod DNA sequence similarities ≥98% with records in the Barcode of Life Database, 257 operational taxonomy units were assigned to 8 orders, 40 families, 90 genera and 89 species. These taxa included 15 insect pests, 5 of which were macadamia pests. Among the latter group, Nezara viridula (Pentatomidae; green vegetable bug), considered a major pest, was present in 23% of all faecal samples collected. Results also showed that resource partitioning in this system is low, as most bird species shared large proportion of their diets by feeding primarily on lepidopteran, dipteran and arachnids. Dietary composition differed between some species, most likely because of differences in foraging behaviour. Overall, this study reached a level of taxonomic resolution never achieved before in the studied species, thus contributing to a significant improvement in the avian ecological knowledge. Our results showed that bird communities prey upon economically important pests in macadamia orchards. This study set a precedent by exploring avian pest-reduction services using next-generation sequencing, which could contribute to the conservation of avian communities and their natural habitats in agricultural systems.

Using Next-Generation Sequencing to Contrast the Diet and Explore Pest-Reduction Services of Sympatric Bird Species in Macadamia Orchards in Australia

PubMed Central

Crisol-Martínez, Eduardo; Moreno-Moyano, Laura T.; Wormington, Kevin R.; Brown, Philip H.; Stanley, Dragana

2016-01-01

Worldwide, avian communities inhabiting agro-ecosystems are threatened as a consequence of agricultural intensification. Unravelling their ecological role is essential to focus conservation efforts. Dietary analysis can elucidate bird-insect interactions and expose avian pest-reduction services, thus supporting avian conservation. In this study, we used next-generation sequencing to analyse the dietary arthropod contents of 11 sympatric bird species foraging in macadamia orchards in eastern Australia. Across all species and based on arthropod DNA sequence similarities ≥98% with records in the Barcode of Life Database, 257 operational taxonomy units were assigned to 8 orders, 40 families, 90 genera and 89 species. These taxa included 15 insect pests, 5 of which were macadamia pests. Among the latter group, Nezara viridula (Pentatomidae; green vegetable bug), considered a major pest, was present in 23% of all faecal samples collected. Results also showed that resource partitioning in this system is low, as most bird species shared large proportion of their diets by feeding primarily on lepidopteran, dipteran and arachnids. Dietary composition differed between some species, most likely because of differences in foraging behaviour. Overall, this study reached a level of taxonomic resolution never achieved before in the studied species, thus contributing to a significant improvement in the avian ecological knowledge. Our results showed that bird communities prey upon economically important pests in macadamia orchards. This study set a precedent by exploring avian pest-reduction services using next-generation sequencing, which could contribute to the conservation of avian communities and their natural habitats in agricultural systems. PMID:26930484

Predictive Genomic Analyses Inform the Basis for Vitamin Metabolism and Provisioning in Bacteria-Arthropod Endosymbioses

PubMed Central

Serbus, Laura R.; Rodriguez, Brian Garcia; Sharmin, Zinat; Momtaz, A. J. M. Zehadee; Christensen, Steen

2017-01-01

The requirement of vitamins for core metabolic processes creates a unique set of pressures for arthropods subsisting on nutrient-limited diets. While endosymbiotic bacteria carried by arthropods have been widely implicated in vitamin provisioning, the underlying molecular mechanisms are not well understood. To address this issue, standardized predictive assessment of vitamin metabolism was performed in 50 endosymbionts of insects and arachnids. The results predicted that arthropod endosymbionts overall have little capacity for complete de novo biosynthesis of conventional or active vitamin forms. Partial biosynthesis pathways were commonly predicted, suggesting a substantial role in vitamin provisioning. Neither taxonomic relationships between host and symbiont, nor the mode of host-symbiont interaction were clear predictors of endosymbiont vitamin pathway capacity. Endosymbiont genome size and the synthetic capacity of nonsymbiont taxonomic relatives were more reliable predictors. We developed a new software application that also predicted that last-step conversion of intermediates into active vitamin forms may contribute further to vitamin biosynthesis by endosymbionts. Most instances of predicted vitamin conversion were paralleled by predictions of vitamin use. This is consistent with achievement of provisioning in some cases through upregulation of pathways that were retained for endosymbiont benefit. The predicted absence of other enzyme classes further suggests a baseline of vitamin requirement by the majority of endosymbionts, as well as some instances of putative mutualism. Adaptation of this workflow to analysis of other organisms and metabolic pathways will provide new routes for considering the molecular basis for symbiosis on a comprehensive scale. PMID:28455417

Amblypygids: Model Organisms for the Study of Arthropod Navigation Mechanisms in Complex Environments?

PubMed Central

Wiegmann, Daniel D.; Hebets, Eileen A.; Gronenberg, Wulfila; Graving, Jacob M.; Bingman, Verner P.

2016-01-01

Navigation is an ideal behavioral model for the study of sensory system integration and the neural substrates associated with complex behavior. For this broader purpose, however, it may be profitable to develop new model systems that are both tractable and sufficiently complex to ensure that information derived from a single sensory modality and path integration are inadequate to locate a goal. Here, we discuss some recent discoveries related to navigation by amblypygids, nocturnal arachnids that inhabit the tropics and sub-tropics. Nocturnal displacement experiments under the cover of a tropical rainforest reveal that these animals possess navigational abilities that are reminiscent, albeit on a smaller spatial scale, of true-navigating vertebrates. Specialized legs, called antenniform legs, which possess hundreds of olfactory and tactile sensory hairs, and vision appear to be involved. These animals also have enormous mushroom bodies, higher-order brain regions that, in insects, integrate contextual cues and may be involved in spatial memory. In amblypygids, the complexity of a nocturnal rainforest may impose navigational challenges that favor the integration of information derived from multimodal cues. Moreover, the movement of these animals is easily studied in the laboratory and putative neural integration sites of sensory information can be manipulated. Thus, amblypygids could serve as model organisms for the discovery of neural substrates associated with a unique and potentially sophisticated navigational capability. The diversity of habitats in which amblypygids are found also offers an opportunity for comparative studies of sensory integration and ecological selection pressures on navigation mechanisms. PMID:27014008

Predictive Genomic Analyses Inform the Basis for Vitamin Metabolism and Provisioning in Bacteria-Arthropod Endosymbioses.

PubMed

Serbus, Laura R; Rodriguez, Brian Garcia; Sharmin, Zinat; Momtaz, A J M Zehadee; Christensen, Steen

2017-06-07

The requirement of vitamins for core metabolic processes creates a unique set of pressures for arthropods subsisting on nutrient-limited diets. While endosymbiotic bacteria carried by arthropods have been widely implicated in vitamin provisioning, the underlying molecular mechanisms are not well understood. To address this issue, standardized predictive assessment of vitamin metabolism was performed in 50 endosymbionts of insects and arachnids. The results predicted that arthropod endosymbionts overall have little capacity for complete de novo biosynthesis of conventional or active vitamin forms. Partial biosynthesis pathways were commonly predicted, suggesting a substantial role in vitamin provisioning. Neither taxonomic relationships between host and symbiont, nor the mode of host-symbiont interaction were clear predictors of endosymbiont vitamin pathway capacity. Endosymbiont genome size and the synthetic capacity of nonsymbiont taxonomic relatives were more reliable predictors. We developed a new software application that also predicted that last-step conversion of intermediates into active vitamin forms may contribute further to vitamin biosynthesis by endosymbionts. Most instances of predicted vitamin conversion were paralleled by predictions of vitamin use. This is consistent with achievement of provisioning in some cases through upregulation of pathways that were retained for endosymbiont benefit. The predicted absence of other enzyme classes further suggests a baseline of vitamin requirement by the majority of endosymbionts, as well as some instances of putative mutualism. Adaptation of this workflow to analysis of other organisms and metabolic pathways will provide new routes for considering the molecular basis for symbiosis on a comprehensive scale. Copyright © 2017 Serbus et al.

Enzymatic properties of venoms from Brazilian scorpions of Tityus genus and the neutralisation potential of therapeutical antivenoms.

PubMed

Venancio, Emerson J; Portaro, Fernanda C V; Kuniyoshi, Alexandre K; Carvalho, Daniela Cajado; Pidde-Queiroz, Giselle; Tambourgi, Denise V

2013-07-01

Tityus scorpion stings are an important public health problem in Brazil, where the incidence of such stings exceeds the incidence of the health problems caused by other venomous animals, including snakes. In this study, we have analysed specific enzymatic activities of the venom from the Brazilian scorpions of Tityus genus, i.e., Tityus serrulatus, Tityus bahiensis and Tityus stigmurus. The data presented here revealed that Tityus spp. venoms exhibited significant hyaluronidase activity but no phospholipase activity. All the venom samples exhibited the ability to hydrolyse Abz-FLRRV-EDDnp and dynorphin 1-13 substrates. These activities were inhibited by 1,10-phenanthroline but not by PMSF, indicating the presence of metalloproteinases in the Tityus spp. venoms. The venom peptidase activity on Abz-FLRRV-EDDnp and on dynorphin 1-13 was partially inhibited by therapeutic Brazilian anti-scorpion and anti-arachnidic antivenoms. Dynorphin 1-13 (YGGFLRRIRPKLK) contains two scissile bonds between the residues Leu-Arg and Arg-Arg that are susceptible to cleavage by the Tityus venom metallopeptidase(s). Their cleavage releases leu-enkephalin, an important bioactive peptide. The detection of metalloproteinase(s) with specificity for both dynorphin 1-13 degradation and leu-enkephalin releasing can be important for the mechanistic understanding of hypotension and bradycardia induction in cases of scorpion stings, whereas hyaluronidases might contribute to the diffusion of the toxins present in these venoms. Furthermore, the limited inhibition of the toxic enzymatic activities by commercial antivenoms illustrates the necessity of improvements in current antivenom preparation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Repeated Evolution of Power-Amplified Predatory Strikes in Trap-Jaw Spiders.

PubMed

Wood, Hannah M; Parkinson, Dilworth Y; Griswold, Charles E; Gillespie, Rosemary G; Elias, Damian O

2016-04-25

Small animals possess intriguing morphological and behavioral traits that allow them to capture prey, including innovative structural mechanisms that produce ballistic movements by amplifying power [1-6]. Power amplification occurs when an organism produces a relatively high power output by releasing slowly stored energy almost instantaneously, resulting in movements that surpass the maximal power output of muscles [7]. For example, trap-jaw, power-amplified mechanisms have been described for several ant genera [5, 8], which have evolved some of the fastest known movements in the animal kingdom [6]. However, power-amplified predatory strikes were not previously known in one of the largest animal classes, the arachnids. Mecysmaucheniidae spiders, which occur only in New Zealand and southern South America, are tiny, cryptic, ground-dwelling spiders that rely on hunting rather than web-building to capture prey [9]. Analysis of high-speed video revealed that power-amplified mechanisms occur in some mecysmaucheniid species, with the fastest species being two orders of magnitude faster than the slowest species. Molecular phylogenetic analysis revealed that power-amplified cheliceral strikes have evolved four times independently within the family. Furthermore, we identified morphological innovations that directly relate to cheliceral function: a highly modified carapace in which the cheliceral muscles are oriented horizontally; modification of a cheliceral sclerite to have muscle attachments; and, in the power-amplified species, a thicker clypeus and clypeal apodemes. These structural innovations may have set the stage for the parallel evolution of ballistic predatory strikes. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Spiders and predatory mites in the canopies of organically managed Montenegrina tangerine trees, in Montenegro County, RS].

PubMed

de Morais, Rosana M; Ott, Ricardo; Ott, Ana P; Redaelli, Luiza R

2007-01-01

A survey was conducted to study the spider and predatory mite fauna occurring in the canopies of tangerine trees (Citrus deliciosa Tenore, cultivar Montenegrina) of an organically managed orchard, at Montenegro County, RS. During a year, fortnightly, 24 randomly trees were selected and sampled in two canopies areas, by using a sheet of white cloth (1 m(2)). A total of 3,129 arachnids were collected, being 2,559 spiders and 570 mites. Based on the adults, 53 species of Araneae were recognized, belonging to eight families. Among those, the most abundant were Sphecozone sp. (Linyphiidae) (21.8%) and Chrysso pulcherrima (Mello-Leitão) (Theridiidae) (9.9%). Autumn exhibited the greatest abundance of young and adults of Araneae (29.2%) and spring was the season richest in species (40). Margalef and Shannon-Wiener diversity indexes also showed the highest values in spring. The latter index did not show differences among seasons. Simpson complementary index was equal among seasons, reflecting the same degree of species dominance. In Acari, eight species were identified in three families. The most abundant species were the mites Leptus sp.1 (Erythraeidae) (59.4%) and Amblyseius saopaulus Denmark & Muma (Phytoseiidae) (30%). Autumn was the season richest in mite species (eight). The highest abundance (47%) was observed on winter and the lowest (0.88%) on summer. Among mites, Phytoseiidae showed the highest richness. Among the spiders, Anyphaenidae was the most abundant and Theridiidae had the highest species richness, following the patterns observed for the group.

The risky business of being an entomologist: A systematic review.

PubMed

Stanhope, Jessica; Carver, Scott; Weinstein, Philip

2015-07-01

Adverse work-related health outcomes are a significant problem worldwide. Entomologists, including arthropod breeders, are a unique occupational group exposed to potentially harmful arthropods, pesticides, and other more generic hazards. These exposures may place them at risk of a range of adverse work-related health outcomes. To determine what adverse work-related health outcomes entomologists have experienced, the incidence/prevalence of these outcomes, and what occupational management strategies have been employed by entomologists, and their effectiveness. A systematic search of eight databases was undertaken to identify studies informing the review objectives. Data pertaining to country, year, design, work-exposure, adverse work-related health outcomes, incidence/prevalence of these outcomes, and occupational management strategies were extracted, and reported descriptively. Results showed entomologists experienced work-related allergies, venom reactions, infections, infestations and delusional parasitosis. These related to exposure to insects, arachnids, chilopods and entognathans, and non-arthropod exposures, e.g. arthropod feed. Few studies reported the incidence/prevalence of such conditions, or work-related management strategies utilised by entomologists. There were no studies that specifically investigated the effectiveness of potential management strategies for entomologists as a population. Indeed, critical appraisal analysis indicated poor research quality in this area, which is a significant research gap. Entomologists are a diverse, unique occupational group, at risk of a range of adverse work-related health outcomes. This study represents the first systematic review of their work-related health risks. Future studies investigating the prevalence of adverse work-related health outcomes for entomologists, and the effectiveness of management strategies are warranted to decrease the disease burden of this otherwise understudied group. Copyright © 2015

Gluing the 'unwettable': soil-dwelling harvestmen use viscoelastic fluids for capturing springtails.

PubMed

Wolff, Jonas O; Schönhofer, Axel L; Schaber, Clemens F; Gorb, Stanislav N

2014-10-01

Gluing can be a highly efficient mechanism of prey capture, as it should require less complex sensory-muscular feedback. Whereas it is well known in insects, this mechanism is much less studied in arachnids, except spiders. Soil-dwelling harvestmen (Opiliones, Nemastomatidae) bear drumstick-like glandular hairs (clavate setae) at their pedipalps, which were previously hypothesized to be sticky and used in prey capture. However, clear evidence for this was lacking to date. Using high-speed videography, we found that the harvestman Mitostoma chrysomelas was able to capture fast-moving springtails (Collembola) just by a slight touch of the pedipalp. Adhesion of single clavate setae increased proportionally with pull-off velocity, from 1 μN at 1 μm s(-1) up to 7 μN at 1 mm s(-1), which corresponds to the typical weight of springtails. Stretched glue droplets exhibited characteristics of a viscoelastic fluid forming beads-on-a-string morphology over time, similar to spider capture threads and the sticky tentacles of carnivorous plants. These analogies indicate that viscoelasticity is a highly efficient mechanism for prey capture, as it holds stronger the faster the struggling prey moves. Cryo-scanning electron microscopy of snap-frozen harvestmen with glued springtails revealed that the gluey secretions have a high affinity to wet the microstructured cuticle of collembolans, which was previously reported to be barely wettable for both polar and non-polar liquids. Glue droplets can be contaminated with the detached scaly setae of collembolans, which may represent a counter-adaptation against entrapment by the glue, similar to the scaly surfaces of Lepidoptera and Trichoptera (Insecta) facilitating escape from spider webs. © 2014. Published by The Company of Biologists Ltd.

Environmental metabarcodes for insects: in silico PCR reveals potential for taxonomic bias.

PubMed

Clarke, Laurence J; Soubrier, Julien; Weyrich, Laura S; Cooper, Alan

2014-11-01

Studies of insect assemblages are suited to the simultaneous DNA-based identification of multiple taxa known as metabarcoding. To obtain accurate estimates of diversity, metabarcoding markers ideally possess appropriate taxonomic coverage to avoid PCR-amplification bias, as well as sufficient sequence divergence to resolve species. We used in silico PCR to compare the taxonomic coverage and resolution of newly designed insect metabarcodes (targeting 16S) with that of existing markers [16S and cytochrome oxidase c subunit I (COI)] and then compared their efficiency in vitro. Existing metabarcoding primers amplified in silico <75% of insect species with complete mitochondrial genomes available, whereas new primers targeting 16S provided >90% coverage. Furthermore, metabarcodes targeting COI appeared to introduce taxonomic PCR-amplification bias, typically amplifying a greater percentage of Lepidoptera and Diptera species, while failing to amplify certain orders in silico. To test whether bias predicted in silico was observed in vitro, we created an artificial DNA blend containing equal amounts of DNA from 14 species, representing 11 insect orders and one arachnid. We PCR-amplified the blend using five primer sets, targeting either COI or 16S, with high-throughput amplicon sequencing yielding more than 6 million reads. In vitro results typically corresponded to in silico PCR predictions, with newly designed 16S primers detecting 11 insect taxa present, thus providing equivalent or better taxonomic coverage than COI metabarcodes. Our results demonstrate that in silico PCR is a useful tool for predicting taxonomic bias in mixed template PCR and that researchers should be wary of potential bias when selecting metabarcoding markers. © 2014 John Wiley & Sons Ltd.

Insects and allies associated with bromeliads: a review

PubMed Central

Frank, J. H.; Lounibos, L. P.

2009-01-01

Summary Bromeliads are a Neotropical plant family (Bromeliaceae) with about 2,900 described species. They vary considerably in architecture. Many impound water in their inner leaf axils to form phytotelmata (plant pools), providing habitat for terrestrial arthropods with aquatic larvae, while their outer axils provide terraria for an assemblage of fully terrestrial arthropods. Many bromeliads are epiphytic. Dominant terrestrial arthropods with aquatic larvae inhabiting bromeliad phytotelmata are typically larvae of Diptera, of which at least 16 families have been reported, but in some circumstances are Coleoptera, of which only three families have been reported. Other groups include crabs and the insect orders Odonata, Plecoptera, and Trichoptera, plus Hemiptera with adults active on the water surface. The hundreds of arthropod species are detritivores or predators and do not harm their host plants. Many of them are specialists to this habitat. Terrestrial arthropods with terrestrial larvae inhabiting bromeliad terraria include many more arachnid and insect orders, but relatively few specialists to this habitat. They, too, are detritivores or predators. Arthropod herbivores, especially Curculionidae (Coleoptera) and Lepidoptera, consume leaves, stems, flowers, pollen, and roots of bromeliads. Some herbivores consume nectar, and some of these and other arthropods provide pollination and even seed-dispersal. Ants have complex relationships with bromeliads, a few being herbivores, some guarding the plants from herbivory, and some merely nesting in bromeliad terraria. A few serve as food for carnivorous bromeliads, which also consume other terrestrial insects. Bromeliads are visited by far more species of arthropods than breed in them. This is especially notable during dry seasons, when bromeliads provide moist refugia. PMID:20209047

Feeding habits, sexual dimorphism and size at maturity of the lizard Cnemidophorus ocellifer (Spix, 1825) (Teiidae) in a reforested restinga habitat in northeastern Brazil.

PubMed

Santana, G G; Vasconcellos, A; Gadelha, Y E A; Vieira, W L S; Almeida, W O; Nóbrega, R P; Alves, R R N

2010-05-01

The feeding habits, the sexual dimorphism in size and sexual maturity of the actively foraging lizard Cnemidophorusocellifer were analysed in an area of a reforested Restinga habitat located in the municipality of Mataraca, along the northern-most coast of Paraíba State, Brazil. Seventy-five specimens of C. ocellifer were examined (46 males and 29A females). Of this total, only 23 specimens had prey in their stomachs. The most frequent prey consumed items were orthopterans (50%), coleopterans (23.9%) and arachnids (10.9%); termites and insect larvae were less consumed (both with 2.2%). There were no significant differences observed between the numbers of prey consumed by either males or females. There were significant differences in SVL (snout-vent length) between the sexes, with males attaining larger SVL values. When the influence of SVL was removed from the analyses, sexual dimorphism in the form was still reflected in the head size of these lizards. Sexual maturity in females and males was attained with SVL of 42.2 and 49.0 mm respectively. Although no significant difference was observed between the SVL of the females and the number of eggs produced, there was a clear tendency for larger females to produce more eggs. The low structural complexity of the vegetation and the poor soil quality in the reforested restinga area examined does not furnish favourable habitat for insect and termite larvae, contributing to the marked differences in the diet of the population of C. ocellifer observed in the present study in relation to the diet of their conspecifics in undisturbed areas of restinga, cerrado and caatinga.

Resistance of Cultivated Tomato to Cell Content-Feeding Herbivores Is Regulated by the Octadecanoid-Signaling Pathway1

PubMed Central

Li, Chuanyou; Williams, Mark M.; Loh, Ying-Tsu; Lee, Gyu In; Howe, Gregg A.

2002-01-01

The octadecanoid signaling pathway has been shown to play an important role in plant defense against various chewing insects and some pathogenic fungi. Here, we examined the interaction of a cell-content feeding arachnid herbivore, the two-spotted spider mite (Tetranychus urticae Koch), with cultivated tomato (Lycopersicon esculentum) and an isogenic mutant line (defenseless-1 [def-1]) that is deficient in the biosynthesis of the octadecanoid pathway-derived signal, jasmonic acid (JA). Spider mite feeding and fecundity on def-1 plants was significantly greater than on wild-type plants. Decreased resistance of def-1 plants was correlated with reduced JA accumulation and expression of defensive proteinase inhibitor (PI) genes, which were induced in mite-damaged wild-type leaves. Treatment of def-1 plants with methyl-JA restored resistance to spider mite feeding and reduced the fecundity of female mites. Plants expressing a 35S::prosystemin transgene that constitutively activates the octadecanoid pathway in a Def-1-dependent manner were highly resistant to attack by spider mites and western flower thrips (Frankliniella occidentalis), another cell-content feeder of economic importance. These findings indicate that activation of the octadecanoid signaling pathway promotes resistance of tomato to a broad spectrum of herbivores. The techniques of amplified fragment length polymorphism (AFLP) and bulk segregant analysis were used to map the Def-1 gene to a region on the long arm of chromosome 3 that is genetically separable from the map position of known JA biosynthetic genes. Tight linkage of Def-1 to a T-DNA insertion harboring the maize (Zea mays) Dissociation transposable element suggests a strategy for directed transposon tagging of the gene. PMID:12226528

The Unique Morgue Ubiquitination Protein Is Conserved in a Diverse but Restricted Set of Invertebrates

PubMed Central

Zhou, Ying; Carpenter, Zachary W.; Brennan, Gregory

2009-01-01

Drosophila Morgue is a unique ubiquitination protein that facilitates programmed cell death and associates with DIAP1, a critical cell death inhibitor with E3 ubiquitin ligase activity. Morgue possesses a unique combination of functional domains typically associated with distinct types of ubiquitination enzymes. This includes an F box characteristic of the substrate-binding subunit in Skp, Cullin, and F box (SCF)-type ubiquitin E3 ligase complexes and a variant ubiquitin E2 conjugase domain where the active site cysteine is replaced by a glycine. Morgue also contains a single C4-type zinc finger motif. This architecture suggests potentially novel ubiquitination activities for Morgue. In this study, we address the evolutionary origins of this distinctive protein utilizing a combination of bioinformatics and molecular biology approaches. We find that Morgue exhibits widespread but restricted phylogenetic distribution among metazoans. Morgue proteins were identified in a wide range of Protostome phyla, including Arthropoda, Annelida, Mollusca, Nematoda, and Platyhelminthes. However, with one potential exception, Morgue was not detected in Deuterostomes, including Chordates, Hemichordates, or Echinoderms. Morgue was also not found in Ctenophora, Cnidaria, Placozoa, or Porifera. Characterization of Morgue sequences within specific animal lineages suggests that gene deletion or acquisition has occurred during divergence of nematodes and that at least one arachnid expresses an atypical form of Morgue consisting only of the variant E2 conjugase domain. Analysis of the organization of several morgue genes suggests that exon-shuffling events have contributed to the evolution of the Morgue protein. These results suggest that Morgue mediates conserved and distinctive ubiquitination functions in specific cell death pathways. PMID:19602541

Traps of carnivorous pitcher plants as a habitat: composition of the fluid, biodiversity and mutualistic activities

PubMed Central

Adlassnig, Wolfram; Peroutka, Marianne; Lendl, Thomas

2011-01-01

Background Carnivorous pitcher plants (CPPs) use cone-shaped leaves to trap animals for nutrient supply but are not able to kill all intruders of their traps. Numerous species, ranging from bacteria to vertrebrates, survive and propagate in the otherwise deadly traps. This paper reviews the literature on phytotelmata of CPPs. Pitcher Fluid as a Habitat The volumes of pitchers range from 0·2 mL to 1·5 L. In Nepenthes and Cephalotus, the fluid is secreted by the trap; the other genera collect rain water. The fluid is usually acidic, rich in O2 and contains digestive enzymes. In some taxa, toxins or detergents are found, or the fluid is extremely viscous. In Heliamphora or Sarracenia, the fluid differs little from pure water. Inquiline Diversity Pitcher inquilines comprise bacteria, protozoa, algae, fungi, rotifers, crustaceans, arachnids, insects and amphibia. The dominant groups are protists and Dipteran larvae. The various species of CPPs host different sets of inquilines. Sarracenia purpurea hosts up to 165 species of inquilines, followed by Nepenthes ampullaria with 59 species, compared with only three species from Brocchinia reducta. Reasons for these differences include size, the life span of the pitcher as well as its fluid. Mutualistic Activities Inquilines closely interact with their host. Some live as parasites, but the vast majority are mutualists. Beneficial activities include secretion of enzymes, feeding on the plant's prey and successive excretion of inorganic nutrients, mechanical break up of the prey, removal of excessive prey and assimilation of atmospheric N2. Conclusions There is strong evidence that CPPs influence their phytotelm. Two strategies can be distinguished: (1) Nepenthes and Cephalotus produce acidic, toxic or digestive fluids and host a limited diversity of inquilines. (2) Genera without efficient enzymes such as Sarracenia or Heliamphora host diverse organisms and depend to a large extent on their symbionts for prey utilization

Traps of carnivorous pitcher plants as a habitat: composition of the fluid, biodiversity and mutualistic activities.

PubMed

Adlassnig, Wolfram; Peroutka, Marianne; Lendl, Thomas

2011-02-01

Carnivorous pitcher plants (CPPs) use cone-shaped leaves to trap animals for nutrient supply but are not able to kill all intruders of their traps. Numerous species, ranging from bacteria to vertrebrates, survive and propagate in the otherwise deadly traps. This paper reviews the literature on phytotelmata of CPPs. Fluid as a Habitat The volumes of pitchers range from 0·2 mL to 1·5 L. In Nepenthes and Cephalotus, the fluid is secreted by the trap; the other genera collect rain water. The fluid is usually acidic, rich in O(2) and contains digestive enzymes. In some taxa, toxins or detergents are found, or the fluid is extremely viscous. In Heliamphora or Sarracenia, the fluid differs little from pure water. Diversity Pitcher inquilines comprise bacteria, protozoa, algae, fungi, rotifers, crustaceans, arachnids, insects and amphibia. The dominant groups are protists and Dipteran larvae. The various species of CPPs host different sets of inquilines. Sarracenia purpurea hosts up to 165 species of inquilines, followed by Nepenthes ampullaria with 59 species, compared with only three species from Brocchinia reducta. Reasons for these differences include size, the life span of the pitcher as well as its fluid. MUTUALISTIC: Activities Inquilines closely interact with their host. Some live as parasites, but the vast majority are mutualists. Beneficial activities include secretion of enzymes, feeding on the plant's prey and successive excretion of inorganic nutrients, mechanical break up of the prey, removal of excessive prey and assimilation of atmospheric N(2). There is strong evidence that CPPs influence their phytotelm. Two strategies can be distinguished: (1) Nepenthes and Cephalotus produce acidic, toxic or digestive fluids and host a limited diversity of inquilines. (2) Genera without efficient enzymes such as Sarracenia or Heliamphora host diverse organisms and depend to a large extent on their symbionts for prey utilization.

Origin and evolution of the panarthropod head - A palaeobiological and developmental perspective.

PubMed

Ortega-Hernández, Javier; Janssen, Ralf; Budd, Graham E

2017-05-01

The panarthropod head represents a complex body region that has evolved through the integration and functional specialization of the anterior appendage-bearing segments. Advances in the developmental biology of diverse extant organisms have led to a substantial clarity regarding the relationships of segmental homology between Onychophora (velvet worms), Tardigrada (water bears), and Euarthropoda (e.g. arachnids, myriapods, crustaceans, hexapods). The improved understanding of the segmental organization in panarthropods offers a novel perspective for interpreting the ubiquitous Cambrian fossil record of these successful animals. A combined palaeobiological and developmental approach to the study of the panarthropod head through deep time leads us to propose a consensus hypothesis for the intricate evolutionary history of this important tagma. The contribution of exceptionally preserved brains in Cambrian fossils - together with the recognition of segmentally informative morphological characters - illuminate the polarity for major anatomical features. The euarthropod stem-lineage provides a detailed view of the step-wise acquisition of critical characters, including the origin of a multiappendicular head formed by the fusion of several segments, and the transformation of the ancestral protocerebral limb pair into the labrum, following the postero-ventral migration of the mouth opening. Stem-group onychophorans demonstrate an independent ventral migration of the mouth and development of a multisegmented head, as well as the differentiation of the deutocerebral limbs as expressed in extant representatives. The anterior organization of crown-group Tardigrada retains several ancestral features, such as an anterior-facing mouth and one-segmented head. The proposed model aims to clarify contentious issues on the evolution of the panarthropod head, and lays the foundation from which to further address this complex subject in the future. Copyright © 2016 Elsevier Ltd. All

Bacillus thuringiensis Is an Environmental Pathogen and Host-Specificity Has Developed as an Adaptation to Human-Generated Ecological Niches

PubMed Central

Argôlo-Filho, Ronaldo Costa; Loguercio, Leandro Lopes

2013-01-01

Bacillus thuringiensis (Bt) has been used successfully as a biopesticide for more than 60 years. More recently, genes encoding their toxins have been used to transform plants and other organisms. Despite the large amount of research on this bacterium, its true ecology is still a matter of debate, with two major viewpoints dominating: while some understand Bt as an insect pathogen, others see it as a saprophytic bacteria from soil. In this context, Bt’s pathogenicity to other taxa and the possibility that insects may not be the primary targets of Bt are also ideas that further complicate this scenario. The existence of conflicting research results, the difficulty in developing broader ecological and genetics studies, and the great genetic plasticity of this species has cluttered a definitive concept. In this review, we gathered information on the aspects of Bt ecology that are often ignored, in the attempt to clarify the lifestyle, mechanisms of transmission and target host range of this bacterial species. As a result, we propose an integrated view to account for Bt ecology. Although Bt is indeed a pathogenic bacterium that possesses a broad arsenal for virulence and defense mechanisms, as well as a wide range of target hosts, this seems to be an adaptation to specific ecological changes acting on a versatile and cosmopolitan environmental bacterium. Bt pathogenicity and host-specificity was favored evolutionarily by increased populations of certain insect species (or other host animals), whose availability for colonization were mostly caused by anthropogenic activities. These have generated the conditions for ecological imbalances that favored dominance of specific populations of insects, arachnids, nematodes, etc., in certain areas, with narrower genetic backgrounds. These conditions provided the selective pressure for development of new hosts for pathogenic interactions, and so, host specificity of certain strains. PMID:26462580

Spintharus flavidus in the Caribbean-a 30 million year biogeographical history and radiation of a 'widespread species'.

PubMed

Dziki, Austin; Binford, Greta J; Coddington, Jonathan A; Agnarsson, Ingi

2015-01-01

The Caribbean island biota is characterized by high levels of endemism, the result of an interplay between colonization opportunities on islands and effective oceanic barriers among them. A relatively small percentage of the biota is represented by 'widespread species,' presumably taxa for which oceanic barriers are ineffective. Few studies have explored in detail the genetic structure of widespread Caribbean taxa. The cobweb spider Spintharus flavidus Hentz, 1850 (Theridiidae) is one of two described Spintharus species and is unique in being widely distributed from northern N. America to Brazil and throughout the Caribbean. As a taxonomic hypothesis, Spintharus "flavidus" predicts maintenance of gene flow among Caribbean islands, a prediction that seems contradicted by known S. flavidus biology, which suggests limited dispersal ability. As part of an extensive survey of Caribbean arachnids (project CarBio), we conducted the first molecular phylogenetic analysis of S. flavidus with the primary goal of testing the 'widespread species' hypothesis. Our results, while limited to three molecular loci, reject the hypothesis of a single widespread species. Instead this lineage seems to represent a radiation with at least 16 species in the Caribbean region. Nearly all are short range endemics with several distinct mainland groups and others are single island endemics. While limited taxon sampling, with a single specimen from S. America, constrains what we can infer about the biogeographical history of the lineage, clear patterns still emerge. Consistent with limited overwater dispersal, we find evidence for a single colonization of the Caribbean about 30 million years ago, coinciding with the timing of the GAARLandia landbridge hypothesis. In sum, S. "flavidus" is not a single species capable of frequent overwater dispersal, but rather a 30 my old radiation of single island endemics that provides preliminary support for a complex and contested geological hypothesis.

Reliable Refuge: Two Sky Island Scorpion Species Select Larger, Thermally Stable Retreat Sites.

PubMed

Becker, Jamie E; Brown, Christopher A

2016-01-01

selection in other arachnids.

Diet composition and terrestrial prey selection of the Laysan teal on Laysan Island

USGS Publications Warehouse

Reynolds, M.H.; Slotterback, J.W.; Walters, J.R.

2006-01-01

The Laysan teal (Anas laysanensis) is an endangered dabbling duck endemic to the Hawaiian Archipelago but currently restricted to a single breeding population on Laysan Island. We studied its diet using fecal analysis and behavioral observations. Laysan teal fecal samples (N=118) contained prey items in 15 primary prey categories with a mean of 2.9 (range 0-7) taxa per sample. Sixty-two of these fecal samples were quantified with 2,270 prey items identified (mean items per sample 37; range 0-205). Based on fecal analysis and behavioral observations, we learned that the Laysan teal is not strictly a macroinsectivore as previously reported, but consumed seeds, succulent leaves, and algae, in addition to adult and larval diptera, ants, lepidoptera, coleoptera, and Artemia. We compared abundance of invertebrates from two terrestrial foraging substrates, soil and standing vegetation, to the abundance of invertebrate prey items counted in fecal samples collected from these habitats for the same period. In the soil substrate, Laysan teal selected two of the most abundant invertebrates, lepidoptera larvae and coleoptera. In the standing vegetation, Laysan teal selected the most abundant taxa: coleoptera. Amphipods were consumed in proportion to their abundance, and small gastropods (Tornatellides sp.), isopods, and arachnids were avoided or were identified in fecal matter in disproportion to their abundance in the foraging habitat. We compared fecal composition of samples collected in aquatic and terrestrial habitats and detected significant differences in samples' species compositions. The conservation implications of the adult Laysan teal's diet are positive, since results indicate that the Laysan teal are opportunistic insectivores, and exhibit dietary flexibility that includes seeds and other food. Dietary flexibility improves the possibility of successfully reestablishing populations on other predator-free islands.

Spintharus flavidus in the Caribbean—a 30 million year biogeographical history and radiation of a ‘widespread species’

PubMed Central

Dziki, Austin; Binford, Greta J.; Coddington, Jonathan A.

2015-01-01

The Caribbean island biota is characterized by high levels of endemism, the result of an interplay between colonization opportunities on islands and effective oceanic barriers among them. A relatively small percentage of the biota is represented by ‘widespread species,’ presumably taxa for which oceanic barriers are ineffective. Few studies have explored in detail the genetic structure of widespread Caribbean taxa. The cobweb spider Spintharus flavidus Hentz, 1850 (Theridiidae) is one of two described Spintharus species and is unique in being widely distributed from northern N. America to Brazil and throughout the Caribbean. As a taxonomic hypothesis, Spintharus “flavidus” predicts maintenance of gene flow among Caribbean islands, a prediction that seems contradicted by known S. flavidus biology, which suggests limited dispersal ability. As part of an extensive survey of Caribbean arachnids (project CarBio), we conducted the first molecular phylogenetic analysis of S. flavidus with the primary goal of testing the ‘widespread species’ hypothesis. Our results, while limited to three molecular loci, reject the hypothesis of a single widespread species. Instead this lineage seems to represent a radiation with at least 16 species in the Caribbean region. Nearly all are short range endemics with several distinct mainland groups and others are single island endemics. While limited taxon sampling, with a single specimen from S. America, constrains what we can infer about the biogeographical history of the lineage, clear patterns still emerge. Consistent with limited overwater dispersal, we find evidence for a single colonization of the Caribbean about 30 million years ago, coinciding with the timing of the GAARLandia landbridge hypothesis. In sum, S. “flavidus” is not a single species capable of frequent overwater dispersal, but rather a 30 my old radiation of single island endemics that provides preliminary support for a complex and contested geological

Fossil moss mites (Arthropoda: Oribatida): an introduction to their morphology and potential for Quaternary paleoecological interpretation

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

Erickson, J.M.

1985-01-01

Although attention has been called to their presence as fossils in Quaternary lake and bog deposits a number of times, the moss mites (Arthropoda; Oribatida) have never been given serious attention during paleoecological work. This study is the first to demonstrate the quality and quantity of oribatid fossil material preserved in post-glacial lacustrine sediments. Oribatids have been identified from Jurassic rocks and from Tertiary ambers in Mexico and the Baltic Region. They are sclerotized, chelicerate, arachnids (Acari) which possess many features that make them readily identifiable from fossil material. Setae, tarsi, genital and anal plates, sensilla, notogastral pits and pores,more » and a wide variety of ornamentation are particularly useful. More than 5000 species in 700 genera occur worldwide. Most are less than 500..mu..m in size. Oribatids are often ecologically specific and may be assigned to restricted habitats. They do not fly and are thus unlikely to be found in sediments beyond their local ranges. Some species are lacustrine; many favor bog habitats. A large literature describes ecological preferences of extant species. More than 10,000 specimens of larval and adult mites have been taken from 72 samples of lake sediment, ranging from <14,700 to <2000 years in age. This report focuses on a dozen 10-gram samples which yielded more than 1300 specimens from 7 genera. Species of Hydrozetes and Limnozetes are abundant in lake sediments; these become rarer and are replaced in peats by a diverse fauna including species of Oripoda, Scapheremaeus, Sphaerozetes, Scheloribates, Magnobates(.), and unidentified taxa. Preservation of delicate setal hairs, genital plates and sensilla allows ready generic identification. SEM photomicrographs serve to illustrate the quality of preservation and the morphologically important features by way of introduction to this under-utilized group.« less

Large Variation in the Ratio of Mitochondrial to Nuclear Mutation Rate across Animals: Implications for Genetic Diversity and the Use of Mitochondrial DNA as a Molecular Marker.

PubMed

Allio, Remi; Donega, Stefano; Galtier, Nicolas; Nabholz, Benoit

2017-11-01

It is commonly assumed that mitochondrial DNA (mtDNA) evolves at a faster rate than nuclear DNA (nuDNA) in animals. This has contributed to the popularity of mtDNA as a molecular marker in evolutionary studies. Analyzing 121 multilocus data sets and four phylogenomic data sets encompassing 4,676 species of animals, we demonstrate that the ratio of mitochondrial over nuclear mutation rate is highly variable among animal taxa. In nonvertebrates, such as insects and arachnids, the ratio of mtDNA over nuDNA mutation rate varies between 2 and 6, whereas it is above 20, on average, in vertebrates such as scaled reptiles and birds. Interestingly, this variation is sufficient to explain the previous report of a similar level of mitochondrial polymorphism, on average, between vertebrates and nonvertebrates, which was originally interpreted as reflecting the effect of pervasive positive selection. Our analysis rather indicates that the among-phyla homogeneity in within-species mtDNA diversity is due to a negative correlation between mtDNA per-generation mutation rate and effective population size, irrespective of the action of natural selection. Finally, we explore the variation in the absolute per-year mutation rate of both mtDNA and nuDNA using a reduced data set for which fossil calibration is available, and discuss the potential determinants of mutation rate variation across genomes and taxa. This study has important implications regarding DNA-based identification methods in predicting that mtDNA barcoding should be less reliable in nonvertebrates than in vertebrates. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Sulfakinin is an important regulator of digestive processes in the migratory locust, Locusta migratoria.

PubMed

Zels, Sven; Dillen, Senne; Crabbé, Katleen; Spit, Jornt; Nachman, Ronald J; Vanden Broeck, Jozef

2015-06-01

Sulfakinin (SK) is a sulfated insect neuropeptide that is best known for its function as a satiety factor. It displays structural and functional similarities with the vertebrate peptides gastrin and cholecystokinin. Peptidomic studies in multiple insects, crustaceans and arachnids have revealed the widespread occurrence of SK in the arthropod phylum. Multiple studies in hemi- and holometabolous insects revealed the pleiotropic nature of this neuropeptide: in addition to its activity as a satiety factor, SK was also reported to affect muscle contraction, digestive enzyme release, odor preference, aggression and metabolism. However, the main site of action seems to be the digestive system of insects. In this study, we have investigated whether SK can intervene in the control of nutrient uptake and digestion in the migratory locust (Locusta migratoria). We provide evidence that sulfakinin reduces food uptake in this species. Furthermore, we discovered that SK has very pronounced effects on the main digestive enzyme secreting parts of the locust gut. It effectively reduced digestive enzyme secretion from both the midgut and gastric caeca. SK injection also elicited a reduction in absorbance and proteolytic activity of the gastric caeca contents. The characteristic sulfation of the tyrosine residue is crucial for the observed effects on digestive enzyme secretion. In an attempt to provide potential leads for the development of peptidomimetic compounds based on SK, we also tested two mimetic analogs of the natural peptide ligand in the digestive enzyme secretion assay. These analogs were able to mimic the effect of the natural SK, but their effects were milder. The results of this study provide new insights into the action of SK on the digestive system in (hemimetabolous) insects. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phenoptosis in arthropods and immortality of social insects.

PubMed

Kartsev, V M

2014-10-01

In general, there are no drastic differences in phenoptosis patterns in plant and animal organisms. However, there are some specific features characteristic for insects and other arthropods: 1) their development includes metamorphosis with different biochemical laws at consecutive developmental stages; 2) arthropods can reduce or stop development and aging when in a state of diapause or temporal cold immobility; 3) their life cycle often correlates with seasonal changes of surroundings; 4) polymorphism is widespread - conspecifics differ by their lifespans and phenoptosis features; 5) lifespan-related sexual dimorphism is common; 6) significant situational plasticity of life cycle organization is an important feature; for example, the German wasp (Paravespula germanica) is obligatorily univoltine in the temperate zone, while in tropical regions its lifespan increases and leads to repeated reproduction; 7) life cycles of closely related species may differ significantly, for example, in contrast to German wasp, some tropical hornets (Vespa) have only one reproduction period. Surprisingly, many insect species have been shown to be subjected to gradual aging and phenoptosis, like the highest mammals. However, queens of social insects and some long-lived arachnids can apparently be considered non-aging organisms. In some species, lifespan is limited to one season, while others live much longer or shorter. Cases of one-time reproduction are rather rare. Aphagia is common in insects (over 10,000 species). Cannibalism is an important mortality factor in insects as well as in spiders. In social insects, which exist only in colonies (families), the lifetime of a colony can be virtually unlimited. However, in case of some species the developmental cycle and death of a colony after its completion are predetermined. Most likely, natural selection in insects does not lengthen individual lifespan, but favors increase in reproduction efficiency based on fast succession of

Biochemical and molecular characterization of the venom from the Cuban scorpion Rhopalurus junceus.

PubMed

García-Gómez, B I; Coronas, F I V; Restano-Cassulini, R; Rodríguez, R R; Possani, L D

2011-07-01

This communication describes the first general biochemical, molecular and functional characterization of the venom from the Cuban blue scorpion Rhopalurus junceus, which is often used as a natural product for anti-cancer therapy in Cuba. The soluble venom of this arachnid is not toxic to mice, injected intraperitoneally at doses up to 200 μg/20 g body weight, but it is deadly to insects at doses of 10 μg per animal. The venom causes typical alpha and beta-effects on Na+ channels, when assayed using patch-clamp techniques in neuroblastoma cells in vitro. It also affects K+ currents conducted by ERG (ether-a-go-go related gene) channels. The soluble venom was shown to display phospholipase, hyaluronidase and anti-microbial activities. High performance liquid chromatography of the soluble venom can separate at least 50 components, among which are peptides lethal to crickets. Four such peptides were isolated to homogeneity and their molecular masses and N-terminal amino acid sequence were determined. The major component (RjAa12f) was fully sequenced by Edman degradation. It contains 64 amino acid residues and four disulfide bridges, similar to other known scorpion toxins. A cDNA library prepared from the venomous glands of one scorpion allowed cloning 18 genes that code for peptides of the venom, including RjA12f and eleven other closely related genes. Sequence analyses and phylogenetic reconstruction of the amino acid sequences deduced from the cloned genes showed that this scorpion contains sodium channel like toxin sequences clearly segregated into two monophyletic clusters. Considering the complex set of effects on Na+ currents verified here, this venom certainly warrant further investigation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Characterization of the immune response of domestic fowl following immunization with proteins extracted from Dermanyssus gallinae.

PubMed

Harrington, David; Din, Hatem Mohi El; Guy, Jonathan; Robinson, Karen; Sparagano, Olivier

2009-03-23

Dermanyssus gallinae is the most significant ectoparasite of European poultry egg laying production systems due to high costs of control and associated production losses as well as adverse effects on bird welfare. In this study, soluble proteins were extracted from unfed D. gallinae (DGE) using a urea-based detergent and ultra-filtration, passed through a 0.22 microm filter and blended aseptically with adjuvant. One group of laying hens was immunized with DGE and adjuvant (Montanide ISA 50 V) whilst another group (Control) received physiological saline and adjuvant. All birds were immunized on two occasions, 21 days apart. Antibody response to immunization was determined by ELISA and western blotting using immunoglobulins (Igs) extracted from egg yolk. DGE immunization of hens resulted in a significant (P<0.05) IgY response compared to controls, although there was no significant difference in IgM response between treatments. A number of proteins were identified by western blotting using IgY antibodies from DGE immunized birds, most prominently at 40 and 230kDa. Analysis of proteins from approximately corresponding bands on SDS-PAGE confirmed the identity of tropomyosin, whilst other proteins showed high sequence homology with myosin and actin from other arachnid and insect species. Immunization of hens with DGE resulted in a 50.6% increase in mite mortality (P<0.001) 17h after feeding when tested by an in vitro mite feeding model. Data in this study demonstrate that somatic antigens from D. gallinae can be used to stimulate a protective immune response in laying hens. Further work is needed to identify other proteins of interest that could confer higher protection against D. gallinae, as well as optimization of the vaccination and in vitro testing protocol.

Predatory Ground Beetles (Insecta: Coleoptera: Carabidae) of the Gaoligong Mountain Region of Western Yunnan Province, China: the Tribe Cyclosomini

NASA Astrophysics Data System (ADS)

Cueva-Dabkoski, M.; Kavanaugh, D.

2013-12-01

Between 1998 and 2007, the California Academy of Sciences (CAS) was the lead institution in a multi-national, multi-disciplinary biodiversity inventory project in the Gaoligong Shan region (GLGS) in the Yunnan province of China. The project surveyed the species diversity of both higher plants and bryophytes, fishes, amphibians, reptiles, birds, mammals and selected groups of arachnids and insects. The GLGS of China is one of the most biodiverse areas in all of Asia, yet it is also very poorly sampled and in great threat from increasing human activities in the region. CAS's biodiversity inventory project there has increased the number of carabid species known from just 50 to more than 550 species, an eleven-fold increase. The task that remains is to identify all of those 500 additional species and describe any that are new to science. This project is part of that larger biodiversity survey. Our objective was to identify and/or describe carabid beetles of the tribe Cyclosomini represented by nearly a hundred specimens collected in the GLSG. Among those specimens, six morphospecies were identified - one belonging to the genus Cyclosomus Latreille 1829, and the other five belonging to the genus Tetragonoderus Dejean 1829. Following this initial identification process, a list of known distributions of taxa in both genera was assembled to determine which described species to consider for comparative work. Original descriptions were then located for candidate species with known distributions in or near the GLGS; and these are being used now in morphological comparison of specimens. Type specimens for each of the candidate species have been requested from various academic institutions, and morphological comparisons with these types are underway. Morphological characteristics being examined include body proportions and overall shape, color of appendages, color and shape of pronotum, elytral color patterns, and shape and internal structure of male genitalia.

Ecological baseline studies at the site of the Barstow 10 MWe pilot solar thermal power system

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

Turner, F.B.

1979-11-01

Baseline ecological measurements and observations were made in 1978 and 1979 at the site of the Barstow pilot 10 MWe solar thermal power system. The station will be constructed on Southern California Edison's Coolwater property. The climate of the area is typical of the Mojave Desert, with high summer temperatures (monthly means of up to 31/sup 0/C), and low rainfall (annual mean of 94 mm). About 66% of the rain falls in winter and spring. About 75% of winds are from the west-southwest to northwest, and mean monthly wind velocities during spring and summer are around 15 to 20 kmmore » hr/sup -1/. Surface soils of the site are sandy, but soils below 3 m are generally well graded sand with some silt and gravel. Some of the soils are highly saline, to an extent precluding plant growth. All soils are alkaline, with pH values as high as 9. Over 130 species of plants have been identified on the site, 18 of which are non-native. Estimated aggregate densities of annual plants range from around 600 to almost 9000 m/sup -2/, depending on sampling locale. Aggregate densities of perennials (including herbaceous species) range from as low as 0.2 to 4.4 m/sup -2/. Creosotebush supports a varied assemblage of sap-feeding and defoliating insects, principally homopterans and orthopterans. Other shrubs are populated with hemipterans, mealybugs, thrips, phytophagous beetles and moth larvae. Common ground-dwelling species are ants, tenebrionid beetles, weevils, various orthopterans, and predatory arachnids. Some 300 different kinds of arthropods were distinguished in samples from the site. The most commonly trapped rodents were kangaroo rats (Dipodomys merriami, D. deserti), pocket mice (Perognathus formosus) and ground squirrels (Spermophilus tereticaudus). Over 60 kinds of birds were observed around the site, many associated with evaporating ponds adjoining the Coolwater Generating Station.« less

The Role of Dust Mites in Allergy.

PubMed

Miller, Jeffrey D

2018-06-23

House dust mites are an unsurpassed cause of atopic sensitization and allergic illness throughout the world. The major allergenic dust mites Dermatophagoides pteronyssinus, Dermatophagoides farinae, Euroglyphus maynei, and Blomia tropicalis are eight-legged members of the Arachnid class. Their approximately 3-month lifespan comprises egg, larval, protonymph, tritonymph, and adult stages, with adults, about one fourth to one third of a millimeter in size, being at the threshold of visibility. The geographic and seasonal distributions of dust mites are determined by their need for adequate humidity, while their distribution within substrates is further determined by their avoidance of light. By contacting the epithelium of the eyes, nose, lower airways, skin, and gut, the allergen-containing particles of dust mites can induce sensitization and atopic symptoms in those organs. Various mite allergens, contained primarily in mite fecal particles but also in shed mite exoskeletons and decaying mite body fragments, have properties that include proteolytic activity, homology with the lipopolysaccharide-binding component of Toll-like receptor 4, homology with other invertebrate tropomyosins, and chitin-cleaving and chitin-binding activity. Mite proteases have direct epithelial effects including the breaching of tight junctions and the stimulation of protease-activated receptors, the latter inducing pruritus, epithelial dysfunction, and cytokine release. Other components, including chitin, unmethylated mite and bacterial DNA, and endotoxin, activate pattern recognition receptors of the innate immune system and act as adjuvants promoting sensitization to mite and other allergens. Clinical conditions resulting from mite sensitization and exposure include rhinitis, sinusitis, conjunctivitis, asthma, and atopic dermatitis. Systemic allergy symptoms can also occur from the ingestion of cross-reacting invertebrates, such as shrimp or snail, or from the accidental ingestion of mite

Birefringent Crystals and Abdominal Discoloration in the Predatory Mite Phytoseiulus persimilis (Acari: Phytoseiidae)

PubMed

Bjørnson; Steiner; Keddie

1997-03-01

In response to grower complaints of poor performance of Phytoseiulus persimilis, mites from 14 commercial insectaries and research colonies were examined for pathogens. Some were found to have abdominal discolorations, manifested initially as two white stripes along the dorsal sides of the body within the Malpighian tubules. Advanced signs appeared as a large, centrally located, white spot or U-shaped discoloration in the distal opisthosoma within the rectum/anal atrium. White material often accumulated and hardened within the anus and formed a rectal plug that inhibited further excretion. Most affected mites were lethargic. Adults and immatures with abdominal discoloration contained numerous densely packed, birefringent, dumbbell-shaped entities. Though occasionally observed in the colon, they occurred most frequently within the Malpighian tubules and/or rectum and anal atrium. Dumbbells measured 2-4 &mgr;m long and contained prominent concentric rings. When observed by transmission electron microscopy, the entities lacked cellular organelles. Asymptomatic mites contained few or no such entities. Dumbbell-shaped inclusions were observed in P. persimilis from all sources examined. High levels of potassium, low levels of phosphorous and sulfur, and traces of chlorine were detected by energy-dispersive X-ray analysis. Guanine and uric acid, known nitrogenous wastes of arachnids, do not contain these elements. The chemical composition and structure indicate that the dumbbells are crystals. Both asymptomatic mites and those specimens exhibiting abdominal discoloration were examined for pathogens using light and transmission electron microscopy. Microsporidia, virus-like particles, and a rickettsia (genus Wolbachia) were observed in some mites but showed no correlation with white abdominal discoloration or associated crystal formation. Neither were pathogens always detected in symptomatic mites. Although birefringent crystals may be naturally occurring excretory

Insect (food) allergy and allergens.

PubMed

de Gier, Steffie; Verhoeckx, Kitty

2018-05-03

Insects represent an alternative for meat and fish in satisfying the increasing demand for sustainable sources of nutrition. Approximately two billion people globally consume insects. They are particularly popular in Asia, Latin America, and Africa. Most research on insect allergy has focussed on occupational or inhalation allergy. Research on insect food safety, including allergenicity, is therefore of great importance. The objective of this review is to provide an overview of cases reporting allergy following insect ingestion, studies on food allergy to insects, proteins involved in insect allergy including cross-reactive proteins, and the possibility to alter the allergenic potential of insects by food processing and digestion. Food allergy to insects has been described for silkworm, mealworm, caterpillars, Bruchus lentis, sago worm, locust, grasshopper, cicada, bee, Clanis bilineata, and the food additive carmine, which is derived from female Dactylopius coccus insects. For cockroaches, which are also edible insects, only studies on inhalation allergy have been described. Various insect allergens have been identified including tropomyosin and arginine kinase, which are both pan-allergens known for their cross-reactivity with homologous proteins in crustaceans and house dust mite. Cross-reactivity and/or co-sensitization of insect tropomyosin and arginine kinase has been demonstrated in house dust mite and seafood (e.g. prawn, shrimp) allergic patients. In addition, many other (allergenic) species (various non-edible insects, arachnids, mites, seafoods, mammals, nematoda, trematoda, plants, and fungi) have been identified with sequence alignment analysis to show potential cross-reactivity with allergens of edible insects. It was also shown that thermal processing and digestion did not eliminate insect protein allergenicity. Although purified natural allergens are scarce and yields are low, recombinant allergens from cockroach, silkworm, and Indian mealmoth are

The complete mitochondrial genome sequence of the spider habronattus oregonensis reveals rearranged and extremely truncated tRNAs

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

Masta, Susan E.; Boore, Jeffrey L.

2004-01-31

We sequenced the entire mitochondrial genome of the jumping spider Habronattus oregonensis of the arachnid order Araneae (Arthropoda: Chelicerata). A number of unusual features distinguish this genome from other chelicerate and arthropod mitochondrial genomes. Most of the transfer RNA gene sequences are greatly reduced in size and cannot be folded into typical cloverleaf-shaped secondary structures. At least nine of the tRNA sequences lack the potential to form TYC arm stem pairings, and instead are inferred to have TV-replacement loops. Furthermore, sequences that could encode the 3' aminoacyl acceptor stems in at least 10 tRNAs appear to be lacking, because fullymore » paired acceptor stems are not possible and because the downstream sequences instead encode adjacent genes. Hence, these appear to be among the smallest known tRNA genes. We postulate that an RNA editing mechanism must exist to restore the 3' aminoacyl acceptor stems in order to allow the tRNAs to function. At least seven tRN As are rearranged with respect to the chelicerate Limulus polyphemus, although the arrangement of the protein-coding genes is identical. Most mitochondrial protein-coding genes of H. oregonensis have ATN as initiation codons, as commonly found in arthropod mtDNAs, but cytochrome oxidase subunit 2 and 3 genes apparently use UUG as an initiation codon. Finally, many of the gene sequences overlap one another and are truncated. This 14,381 bp genome, the first mitochondrial genome of a spider yet sequenced, is one of the smallest arthropod mitochondrial genomes known. We suggest that post transcriptional RNA editing can likely maintain function of the tRNAs while permitting the accumulation of mutations that would otherwise be deleterious. Such mechanisms may have allowed for the minimization of the spider mitochondrial genome.« less

Insect fauna of the Rhode Island coal field

USGS Publications Warehouse

Scudder, Samuel Hubbard

1893-01-01

Some years ago Rev. Edgar F. Clark, then of Providence, Rhode Island, discovered in the Coal-measures of the neighborhood of that city the wing of a cockroach. This stimulated further search by others as well as himself, with the result of finding a fair number and variety of insect types, some of special interest. Most of the discoveries have been made by Mr. Clark (part of them while in the service of the U. S. Geological Survey) and by two young inen of Providence, Messrs. Frederick P. Gorham and Herbert Scholfield, who have been particularly encouraged in their work by Prof. A. S. Packard, of Brown University.All of the specimens have passed under my eye and are herewith described and figured. They consist of Anthracomartus, the first discovered Arachnid in the Carboniferous deposits of the eastern United States; a new genus of Neuropteroidea and one of Protophasmida, each very different from any forms hitherto found in this country, but rather allied to some from the rich Carboniferous beds of Commentry, in France, presenting new features of alliance between the Carboniferous faunas of Europe and America; and a number of cockroaches, all represented by their wings alone. These last show considerable variety of form, both known subfamilies of Paloblattarioe being present, including three genera and nearly a dozen species, the genus Etoblattina, which is the prevalent Carboniferous type the world over, being represented by at least eight species, which again show unusual diversity in size, form, and distribution of the nervules that form the framework of the wing.All the species without exception are new to science and unknown elsewhere.A few additional stones have been submitted to me containing what are apparently parts of the wings of cockroaches, but they are too fragmentary to be of the least value. Nothing more can be said than that they are or may be portions of such wings.It is hoped that the publication of this bulletin will excite further exploration

Biochemical, Transcriptomic and Proteomic Analyses of Digestion in the Scorpion Tityus serrulatus: Insights into Function and Evolution of Digestion in an Ancient Arthropod

PubMed Central

Fuzita, Felipe J.; Pinkse, Martijn W. H.; Patane, José S. L.; Juliano, Maria A.; Verhaert, Peter D. E. M.; Lopes, Adriana R.

2015-01-01

, a large gene duplication of cathepsin L occurred in Arachnida with the sequences from ticks being completely divergent from other arachnids probably due to the particular selective pressures over this group. PMID:25875018

Biochemical, transcriptomic and proteomic analyses of digestion in the scorpion Tityus serrulatus: insights into function and evolution of digestion in an ancient arthropod.

PubMed

Fuzita, Felipe J; Pinkse, Martijn W H; Patane, José S L; Juliano, Maria A; Verhaert, Peter D E M; Lopes, Adriana R

2015-01-01

, a large gene duplication of cathepsin L occurred in Arachnida with the sequences from ticks being completely divergent from other arachnids probably due to the particular selective pressures over this group.

Circus Venomous: an interactive tool for toxinology education.

PubMed

Vohra, Rais; Spano, Susanne

2013-07-01

Clinical education about envenomations and their treatment may convey clinical and zoological details inadequately or flatly. In recent years, the widespread availability of models and videos of venomous species have created unique opportunities for toxinology education. We share our experiences using a new toolkit for educating a diverse array of clinicians, students, and wilderness medicine enthusiasts. We examined the cost, number of participants, and satisfaction data since the initiation of a portable workshop featuring high-fidelity exhibits of venomous species. Termed the "Circus Venomous," this educational toolkit consists of several boxes of props, such as plastic models, photos, and preserved specimens of injurious species. The workshop consists of three phases: 1.) participants view all exhibits and answer clinical questions regarding venomous injuries; 2.) short video clips from television, internet, and cinema are viewed together, and myths about envenomation injuries are debunked; 3.) debriefing session and wrap-up. We have utilized the Circus Venomous to teach medical students, residents, practicing community clinicians, nurses, PAs, national and regional parkmedics, and wilderness enthusiasts. The major cost (about $800) was spent on the purchase of highly durable, lifelike models and well preserved real reptile and arachnid specimens. When formal feedback was solicited, the participants expressed high levels of satisfaction, scoring an average of 4.3, 4.4, and 4.3 out of 5 points in the respective areas of content, presentation, and practical value of the activity. Since we have used this exhibit with approximately 250 participants over 2 years, we estimate the materials cost per participant is approximately $3. The Circus Venomous is a novel, interactive, flexible, and cost-effective teaching tool about envenomation emergencies. We hope that this concept will encourage other clinical educators toward further innovation. Future directions for our

Higher-level molecular phylogeny of the water mites (Acariformes: Prostigmata: Parasitengonina: Hydrachnidiae).

PubMed

Dabert, Miroslawa; Proctor, Heather; Dabert, Jacek

2016-08-01

With nearly 6000 named species, water mites (Hydrachnidiae) represent the largest group of arachnids to have invaded and extensively diversified in freshwater habitats. Water mites together with three other lineages (the terrestrial Erythraiae and Trombidiae, and aquatic Stygothrombiae), make up the hyporder Parasitengonina, which is characterized by having parasitic larvae and predatory nymphs and adults. Relationships between the Hydrachnidiae and other members of the Parasitengonina are unclear, as are relationships among the major lineages of water mites. Monophyly of water mites has been asserted, with the possible exception of the morphologically distinctive Hydrovolzioidea. Here we infer the phylogeny of water mites using multiple molecular markers and including representatives of all superfamilies of Hydrachnidiae and of almost all other Parasitengonina. Our results support a monophyletic Parasitengonina including Trombidiae, Stygothrombiae, and Hydrachnidiae. A monophyletic Hydrachnidiae, including Hydrovolzioidea, is strongly supported. Terrestrial Parasitengonina do not form a monophyletic sister group to water mites. Stygothrombiae is close to water mites but is not nested within this clade. Water mites appear to be derived from ancestors close to Stygothrombiae or the erythraoid group Calyptostomatoidea; however, this relationship is not clear because of extremely short branches in this part of the parasitengonine tree. We recovered with strong support all commonly accepted water mite superfamilies except for Hydryphantoidea, which is clearly paraphyletic. Our data support the previously proposed clades Protohydrachnidia (Hydrovolzioidea and Eylaoidea), Euhydrachnidia (all remaining superfamilies), and the euhydrachnid subclade Neohydrachnidia (Lebertioidea, Hydrachnoidea, Hygrobatoidea, and Arrenuroidea). We found that larval leg structure and locomotory behavior are strongly congruent with the molecular phylogeny. Other morphological and behavioral

A New theraphosid Spider Toxin Causes Early Insect Cell Death by Necrosis When Expressed In Vitro during Recombinant Baculovirus Infection

PubMed Central

Ardisson-Araújo, Daniel Mendes Pereira; Morgado, Fabrício Da Silva; Schwartz, Elisabeth Ferroni; Corzo, Gerardo; Ribeiro, Bergmann Morais

2013-01-01

Baculoviruses are the most studied insect viruses in the world and are used for biological control of agricultural and forest insect pests. They are also used as versatile vectors for expression of heterologous proteins. One of the major problems of their use as biopesticides is their slow speed to kill insects. Thus, to address this shortcoming, insect-specific neurotoxins from arachnids have been introduced into the baculovirus genome solely aiming to improve its virulence. In this work, an insecticide-like toxin gene was obtained from a cDNA derived from the venom glands of the theraphosid spider Brachypelma albiceps. The mature form of the peptide toxin (called Ba3) has a high content of basic amino acid residues, potential for three possible disulfide bonds, and a predicted three-stranded β-sheetDifferent constructions of the gene were engineered for recombinant baculovirus Autographa californica multiple nuclepolyhedrovirus (AcMNPV) expression. Five different forms of Ba3 were assessed; (1) the full-length sequence, (2) the pro-peptide and mature region, (3) only the mature region, and the mature region fused to an (4) insect or a (5) virus-derived signal peptide were inserted separately into the genome of the baculovirus. All the recombinant viruses induced cell death by necrosis earlier in infection relative to a control virus lacking the toxin gene. However, the recombinant virus containing the mature portion of the toxin gene induced a faster cell death than the other recombinants. We found that the toxin construct with the signal peptide and/or pro-peptide regions delayed the necrosis phenotype. When infected cells were subjected to ultrastructural analysis, the cells showed loss of plasma membrane integrity and structural changes in mitochondria before death. Our results suggest this use of baculovirus is a potential tool to help understand or to identify the effect of insect-specific toxic peptides when produced during infection of insect cells. PMID

The ultrastructure of book lung development in the bark scorpion Centruroides gracilis (Scorpiones: Buthidae)

PubMed Central

2011-01-01

Background Near the end of the nineteenth century the hypothesis was presented for the homology of book lungs in arachnids and book gills in the horseshoe crab. Early studies with the light microscope showed that book gill lamellae are formed by outgrowth and possibly some invagination (infolding) of hypodermis (epithelium) from the posterior surface of opisthosomal limb buds. Scorpion book lungs are formed near the bilateral sites of earlier limb buds. Hypodermal invaginations in the ventral opisthosoma result in spiracles and sac-like cavities (atria). In early histological sections of embryo book lungs, widening of the atrial entrance of some lamellae (air channels, air sacs, saccules) was interpreted as an indication of invagination as hypothesized for book gill lamellae. The hypodermal infolding was thought to produce the many rows of lamellar precursor cells anterior to the atrium. The ultrastructure of scorpion book lung development is compared herein with earlier investigations of book gill formation. Results In scorpion embryos, there is ingression (inward migration) of atrial hypodermal cells rather than invagination or infolding of the atrial hypodermal layer. The ingressing cells proliferate and align in rows anterior to the atrium. Their apical-basal polarity results in primordial air channels among double rows of cells. The cuticular walls of the air channels are produced by secretion from the apical surfaces of the aligned cells. Since the precursor cells are in rows, their secreted product is also in rows (i.e., primordial air channels, saccules). For each double row of cells, their opposed basal surfaces are gradually separated by a hemolymph channel of increasing width. Conclusions The results from this and earlier studies show there are differences and similarities in the formation of book lung and book gill lamellae. The homology hypothesis for these respiratory organs is thus supported or not supported depending on which developmental features

Effects of chemical elements in the trophic levels of natural salt marshes.

PubMed

Kamiński, Piotr; Barczak, Tadeusz; Bennewicz, Janina; Jerzak, Leszek; Bogdzińska, Maria; Aleksandrowicz, Oleg; Koim-Puchowska, Beata; Szady-Grad, Małgorzata; Klawe, Jacek J; Woźniak, Alina

2016-06-01

The relationships between the bioaccumulation of Na, K, Ca, Mg, Fe, Zn, Cu, Mn, Co, Cd, and Pb, acidity (pH), salinity (Ec), and organic matter content within trophic levels (water-soil-plants-invertebrates) were studied in saline environments in Poland. Environments included sodium manufactures, wastes utilization areas, dumping grounds, and agriculture cultivation, where disturbed Ca, Mg, and Fe exist and the impact of Cd and Pb is high. We found Zn, Cu, Mn, Co, and Cd accumulation in the leaves of plants and in invertebrates. Our aim was to determine the selectivity exhibited by soil for nutrients and heavy metals and to estimate whether it is important in elucidating how these metals are available for plant/animal uptake in addition to their mobility and stability within soils. We examined four ecological plant groups: trees, shrubs, minor green plants, and water macrophytes. Among invertebrates, we sampled breastplates Malacostraca, small arachnids Arachnida, diplopods Diplopoda, small insects Insecta, and snails Gastropoda. A higher level of chemical elements was found in saline polluted areas (sodium manufactures and anthropogenic sites). Soil acidity and salinity determined the bioaccumulation of free radicals in the trophic levels measured. A pH decrease caused Zn and Cd to increase in sodium manufactures and an increase in Ca, Zn, Cu, Cd, and Pb in the anthropogenic sites. pH increase also caused Na, Mg, and Fe to increase in sodium manufactures and an increase in Na, Fe, Mn, and Co in the anthropogenic sites. There was a significant correlation between these chemical elements and Ec in soils. We found significant relationships between pH and Ec, which were positive in saline areas of sodium manufactures and negative in the anthropogenic and control sites. These dependencies testify that the measurement of the selectivity of cations and their fluctuation in soils provide essential information on the affinity and binding strength in these environments. The

Ultrastructure of book gill development in embryos and first instars of the horseshoe crab Limulus polyphemus L. (Chelicerata, Xiphosura)

PubMed Central

2012-01-01

Background The transmission electron microscope (TEM) is used for the first time to study the development of book gills in the horseshoe crab. Near the end of the nineteenth century the hypothesis was presented for homology and a common ancestry for horseshoe crab book gills and arachnid book lungs. The present developmental study and the author's recent ones of book gills (SEM) and scorpion book lungs (TEM) are intended to clarify early histological work and provide new ultrastructural details for further research and for hypotheses about evolutionary history and relationships. Results The observations herein are in agreement with earlier reports that the book gill lamellae are formed by proliferation and evagination of epithelial cells posterior to opisthosomal branchial appendages. A cartilage-like endoskeleton is produced in the base of the opisthosomal appendages. The lamellar precursor cells in the appendage base proliferate, migrate outward and secrete the lamellar cuticle from their apical surface. A series of external, posteriorly-directed lamellae is formed, with each lamella having a central channel for hemolymph and pillar-type space holders formed from cells of the opposed walls. This repeated, page-like pattern results also in water channels (without space holders) between the sac-like hemolymph lamellae. Conclusions The developmental observations herein and in an earlier study (TEM) of scorpion book lungs show that the lamellae in book gills and book lungs result from some similar activities and features of the precursor epithelial cells: proliferation, migration, alignment and apical/basal polarity with secretion of cuticle from the apical surface and the basal surface in contact with hemolymph. These cellular similarities and the resulting book-like structure suggest a common ancestry, but there are also substantial developmental differences in producing these organs for gas exchange in the different environments, aqueous and terrestrial. For

The diversity and evolution of chelicerate hemocyanins

PubMed Central

2012-01-01

Background Oxygen transport in the hemolymph of many arthropod species is facilitated by large copper-proteins referred to as hemocyanins. Arthropod hemocyanins are hexamers or oligomers of hexamers, which are characterized by a high O2 transport capacity and a high cooperativity, thereby enhancing O2 supply. Hemocyanin subunit sequences had been available from horseshoe crabs (Xiphosura) and various spiders (Araneae), but not from any other chelicerate taxon. To trace the evolution of hemocyanins and the emergence of the large hemocyanin oligomers, hemocyanin cDNA sequences were obtained from representatives of selected chelicerate classes. Results Hemocyanin subunits from a sea spider, a scorpion, a whip scorpion and a whip spider were sequenced. Hemocyanin has been lost in Opiliones, Pseudoscorpiones, Solifugae and Acari, which may be explained by the evolution of trachea (i.e., taxon Apulmonata). Bayesian phylogenetic analysis was used to reconstruct the evolution of hemocyanin subunits and a relaxed molecular clock approach was applied to date the major events. While the sea spider has a simple hexameric hemocyanin, four distinct subunit types evolved before Xiphosura and Arachnida diverged around 470 Ma ago, suggesting the existence of a 4 × 6mer at that time. Subsequently, independent gene duplication events gave rise to the other distinct subunits in each of the 8 × 6mer hemocyanin of Xiphosura and the 4 × 6mer of Arachnida. The hemocyanin sequences were used to infer the evolutionary history of chelicerates. The phylogenetic trees support a basal position of Pycnogonida, a sister group relationship of Xiphosura and Arachnida, and a sister group relationship of the whip scorpions and the whip spiders. Conclusion Formation of a complex hemocyanin oligomer commenced early in the evolution of euchelicerates. A 4 × 6mer hemocyanin consisting of seven subunit types is conserved in most arachnids since more than 400 Ma, although some entelegyne spiders

Reconstructing the diet of a 505-million-year-old arthropod: Sidneyia inexpectans from the Burgess Shale fauna.

PubMed

Zacaï, Axelle; Vannier, Jean; Lerosey-Aubril, Rudy

2016-03-01

The feeding ecology of the 505-million-year-old arthropod Sidneyia inexpectans from the middle Cambrian (Series 3, Stage 5) Burgess Shale fauna (British Columbia, Canada) is revealed by three lines of evidence: the structure of its digestive system, the fossilized contents of its gut and the functional anatomy of its appendages. The digestive tract of Sidneyia is straight, tubular and relatively narrow in the trunk region. It is enlarged into a pear-shaped area in the cephalic region and stretches notably to form a large pocket in the abdomen. The mouth is ventral, posteriorly directed and leads to the midgut via a short tubular structure interpreted as the oesophagus. Anteriorly, three pairs of glands with internal, branching tubular structures open into the digestive tract. These glands have equivalents in various Cambrian arthropod taxa (e.g. naraoiids) and modern arthropods. Their primary function was most likely to digest and assimilate food. The abdominal pocket of Sidneyia concentrates undigested skeletal elements and various residues. It is interpreted here as the functional analogue of the stercoral pocket of some extant terrestrial arachnids (e.g. Araneae, Solifugae), whose primary function is to store food residuals and excretory material until defecation. Analysis of the gut contents indicates that Sidneyia fed largely on small ptychopariid trilobites, brachiopods, possibly agnostids, worms and other undetermined animals. Sidneyia was primarily a durophagous carnivore with predatory and/or scavenging habits, feeding on small invertebrates that lived at the water-sediment interface. There is no evidence for selective feeding. Its food items (e.g. living prey or dead material) were grasped and manipulated ventrally by its anterior appendages, then macerated into ingestible fragments and conveyed to the mouth via the converging action of strong molar-like gnathobases. Digestion probably took place within the anterior midgut via enzymes secreted in the

Scientific research on animal biodiversity is systematically biased towards vertebrates and temperate regions.

PubMed

Titley, Mark A; Snaddon, Jake L; Turner, Edgar C

2017-01-01

Over the last 25 years, research on biodiversity has expanded dramatically, fuelled by increasing threats to the natural world. However, the number of published studies is heavily weighted towards certain taxa, perhaps influencing conservation awareness of and funding for less-popular groups. Few studies have systematically quantified these biases, although information on this topic is important for informing future research and conservation priorities. We investigated: i) which animal taxa are being studied; ii) if any taxonomic biases are the same in temperate and tropical regions; iii) whether the taxon studied is named in the title of papers on biodiversity, perhaps reflecting a perception of what biodiversity is; iv) the geographical distribution of biodiversity research, compared with the distribution of biodiversity and threatened species; and v) the geographical distribution of authors' countries of origin. To do this, we used the search engine Web of Science to systematically sample a subset of the published literature with 'biodiversity' in the title. In total 526 research papers were screened-5% of all papers in Web of Science with biodiversity in the title. For each paper, details on taxonomic group, title phrasing, number of citations, study location, and author locations were recorded. Compared to the proportions of described species, we identified a considerable taxonomic weighting towards vertebrates and an under-representation of invertebrates (particularly arachnids and insects) in the published literature. This discrepancy is more pronounced in highly cited papers, and in tropical regions, with only 43% of biodiversity research in the tropics including invertebrates. Furthermore, while papers on vertebrate taxa typically did not specify the taxonomic group in the title, the converse was true for invertebrate papers. Biodiversity research is also biased geographically: studies are more frequently carried out in developed countries with larger

Refuges, flower strips, biodiversity and agronomic interest.

PubMed

Roy, Grégory; Wateau, Karine; Legrand, Mickaël; Oste, Sandrine

2008-01-01

Several arthropods are natural predators of pests, and they are able to reduce and control their population development. FREDON Nord Pas-de-Calais (Federation Regionate de Defense contre les Organismes Nuisibles = Regional Federation for Pest Control) has begun for a long time to form farmers to the recognition of beneficial arthropods and to show them their usefulness. These beneficial insects or arachnids are present everywhere, in orchards and even in fields which are areas relatively poor in biodiversity. Adults feed in the flower strips instead larvae and some adults feed on preys such as aphids or caterpillars. Most of the time, beneficial insects can regulate pest but sometimes, in agricultural area, they can't make it early enough and efficiently. Their action begin too late and there biodiversity and number are too low. It's possible to enhance their action by manipulating the ecological infrastructures, like sewing flower strips or installing refuges. Flower strips increase the density of natural enemies and make them be present earlier in the field in order to control pests. Refuges permit beneficial's to spend winter on the spot. So they're able to be active and to grow in number earlier. From 2004 to 2007, on the one hand, FREDON Nord Pas-de-Calais has developed a research program. Its purpose was to inventory practices and also tools and means available and to judge the advisability of using such or such beneficial refuge in orchards. On the second hand, it studied the impact in orchard of refuges on population of beneficial's and the difference there were between manufactured refuges and homemade refuges. Interesting prospects were obtained with some of them. Otherwise, since 2003, FREDON has studied flower strips influence on beneficial population and their impact on pest control. In cabbage fields, results of trials have shown that flower strips lead to a reduction of aphid number under acceptable economic level, up to 50 meters from flower strips

Post-Eocene climate change across continental Australia and the diversification of Australasian spiny trapdoor spiders (Idiopidae: Arbanitinae).

PubMed

Rix, Michael G; Cooper, Steven J B; Meusemann, Karen; Klopfstein, Seraina; Harrison, Sophie E; Harvey, Mark S; Austin, Andrew D

2017-04-01

-plugging in transitional arid zone taxa have evolved twice independently in Western Australia, while in Misgolas and Cataxia, burrow door-building behaviours have likely been independently lost at least three times in the eastern Australian mesic zone. We also show that the presence of idiopids in New Zealand (Cantuaria) is likely to be the result of recent dispersal from Australia, rather than ancient continental vicariance. By providing the first comprehensive, continental synopsis of arid zone biogeography in an Australian arachnid lineage, we show that the diversification of arbanitine Idiopidae was intimately associated with climate shifts during the Neogene, resulting in multiple Mio-Pliocene radiations. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of agricultural practices of three crops on the soil communities under Mediterranean conditions: field evaluation.

NASA Astrophysics Data System (ADS)

Leitão, Sara; José Cerejeira, Maria; Abreu, Manuela; Sousa, José Paulo

2014-05-01

Sustainable agricultural production relies on soil communities as the main actors in key soil processes necessary to maintain sustainable soil functioning. Soil biodiversity influences soil physical and chemical characteristics and thus the sustainability of crop and agro-ecosystems functioning. Agricultural practices (e.g.: soil tillage, pesticides and fertilizer applications, irrigation) may affects negatively or positively soil biodiversity and abundances by modifying the relationships between organisms in the soil ecosystem. The present study aimed to study the influence of agricultural practices of three crops (potato, onion and maize) under Mediterranean climate conditions on soil macro- and mesofauna during their entire crop cycles. Effects on soil communities were assessed at a higher tier of environmental risk assessment comprising field testing of indigenous edaphic communities in a selected study-site located in a major agriculture region of Central Portugal, Ribatejo e Oeste, neighbouring protected wetlands. A reference site near the agricultural field site was selected as a Control site to compare the terrestrial communities' composition and variation along the crop cycle. The field soil and Control site soil are sandy loam soils. Crops irrigation was performed by center-pivot (automated sprinkler that rotates in a half a circle area) and by sprinklers. Soil macro- and mesofauna were collected at both sites (field and Control) using two methodologies through pitfall trapping and soil sampling. The community of soil macro- and mesofauna of the three crops field varied versus control site along the crops cycles. Main differences were due to arachnids, coleopterans, ants and adult Diptera presence and abundance. The feeding activity of soil fauna between control site and crop areas varied only for potato and onion crops vs. control site but not among crops. Concentration of pesticides residues in soil did not cause apparent negative effects on the soil

Submicron-Chemical Speciation of Late Albian, Well-Preserved Fossil Samples from Tlayúa, the Mexican Solenhofen.

NASA Astrophysics Data System (ADS)

Marcus, M.; Fakra, S.; Tamura, N.; Alvarado-Ortega, J.; Espinosa-Arruberena, L.; Banfield, J.; Cervini-Silva, J.

2007-12-01

The Tlayúa slurry quarry constitutes the most important paleontological locality in the American continent, and constitutes the second most important locality in its genre worldwide. The importance of Tlayúa strives inderives from the fact that a great diversity of marine and terrestrial fossils in perfect state of preservation have been found, with ages surpassing 115 million yrs. Paleomagnetic and biostratigraphic determinations conducted in ammonites and belemnites indicate that the formation of the Tlayúa slurry dates back to the late Albian. One of the most accepted hypothesis for explaining Tlayúa's formation relies on the deposition of sediments and fauna on a shallow platform of a tropical sea. A similar geographic place is located in Solenhofen, Germany, where slurries have been exploited for more than 200 yrs with a production of approximately 500 species. Remarkably, in the Tepexi del Rio region alone for the past 20 yrs more than 5,000 fossil specimens representing more than 200 species have been collected alone. An The exceptional specimen preservation found in Tlayúa has been attributed to restricted circulation of water resulting in an anaerobic and/or hypersaline environment, coupled with the general absence of infaunal species. There were periods when the deposition site supported a rich planktontic community. Large quantities of calcareous ooze were produced, resulting in rapid burial of the organisms. The presence of diagnostic terrestrial and freshwater organisms, including arachnids, insects, lizards, and chelonians, along with typical marine fauna, suggests that Tlayúa lagoon had periodic freshwater inflow, in addition to the strong marine, lagoonal, and reefal influence. Some organisms were transported into the lagoon when the barrier was breached, probably during periods of heavy rains and hurricanes, or during high tides. Additionally, some fishes from Tlayua have been found to have affinities with recent families known to inhabit

Arthropod eyes: The early Cambrian fossil record and divergent evolution of visual systems.

PubMed

Strausfeld, Nicholas J; Ma, Xiaoya; Edgecombe, Gregory D; Fortey, Richard A; Land, Michael F; Liu, Yu; Cong, Peiyun; Hou, Xianguang

2016-03-01

evolution of sessile eyes equipped with optics typical of extant xiphosurans. Observations of fossil material, including that of trilobites and eurypterids, support the proposition that the ancestral compound eye was the apposition type. Cambrian arthropods include possible precursors of mandibulate eyes. The latter are the modified compound eyes, now sessile, and their underlying optic lobes exemplified by scutigeromorph chilopods, and the mobile stalked compound eyes and more elaborate optic lobes typifying Pancrustacea. Radical divergence from an ancestral apposition type is demonstrated by the evolution of chelicerate eyes, from doublet sessile-eyed stem-group taxa to special apposition eyes of xiphosurans, the compound eyes of eurypterids, and single-lens eyes of arachnids. Different eye types are discussed with respect to possible modes of life of the extinct species that possessed them, comparing these to extant counterparts and the types of visual centers the eyes might have served. Copyright © 2015 Elsevier Ltd. All rights reserved.

Volcano ecology at Chaiten, Chile: geophysical processes interact with forest ecosystems

NASA Astrophysics Data System (ADS)

Swanson, F. J.; Crisafulli, C.; Jones, J. A.; Lara, A.

2010-12-01

The May 2008 eruption of Chaiten Volcano (Chile) offers many insights into volcano ecology -ecological responses to volcanic and associated hydrologic processes and ecosystem development in post-eruption landscapes. Varied intensities of pyroclastic density currents (PDC) and thickness of tephra fall deposits (to 50+ cm) created strong gradients of disturbance in several hundred square kilometers of native forest in a sector north to southeast from the volcano. A gradient from tree removal to toppled forest to standing, scorched forest extends 1.5 km northward from the caldera rim along the trajectory of a PDC. Close to the vent (e.g., 2 km NE from rim) a rain of ca. 10 cm of gravel tephra stripped foliage and twigs from tree canopies; farther away (23 km SE) 10 cm of fine tephra loaded the canopy, causing extensive fall of limbs >8 cm diameter. Even in the severely disturbed, north-flank PDC zone, surviving bamboo, ferns, and other herbs sprouted from pre-eruption soil and other refugia; sprouts of new foliage appeared on the boles and major limbs of several species of toppled and scorched, standing trees; animals including vertebrates (rodents and amphibians) and terrestrial invertebrates (e.g., insects and arachnids) either survived or quickly recolonized; and a diverse fungal community began decomposing the vast dead wood resource. During the second growing season we documented the presence of some plant species that had colonized by seed. Within two years after the eruption secondary ecological disturbances resulting from channel change and overbank deposition of fluvially transported tephra created new patches of damaged forest in riparian zones of streams draining the north flank and along the Rio Rayas and Rio Chaiten. These features parallel observations in the intensively-studied, post-1980-eruption landscape of Mount St. Helens over a similar time period. However, several aspects of ecological response to the two eruptions differ because of differences

Unraveling Molecular Mechanisms for the Unusual Fossil Preservation and Biomineralization Pathways in Tlayúa, the Mexican Solenhofen

NASA Astrophysics Data System (ADS)

Cervini-Silva, J.; Fakra, S.; Alvarado-Ortega, J.; Cornejo-Garrido, H.; Marcus, M.; Hao, Z.; Espinosa-Arruberena, L.; Banfield, J.

2007-12-01

The Tlayúa slurry constitutes the most important paleontological locality in the American continent, and constitutes the second most important locality in its genre worldwide. The importance of Tlayúa strives in the fact that a great diversity of marine and terrestrial fossils in perfect state of preservation have been found, with ages surpassing 115 million yrs. Paleomagnetic determinations and biostratigraphic determinations conducted in amonites and belemnites indicate that the formation of the Tlayúa slurry dates back to the late Albian. On the other hand, fish, reptiles, invertebrates, and vegetables fossil specimens have been found to date back to the Mesozoic Era. Because of this fact is unprecedented worldwide, Tlayúa is nowadays considered patrimony for the humanity. One of the most accepted hypothesis for explaining Tlayúa's formation relies on the deposition of sediments and fauna on a shallow platform of a tropical sea. A similar geographic place is located in Solenhofen, Germany, where slurries have been exploited for more than 200 yrs with a production of approximately 500 species. Remarkably, in the Tepexi del Rio region for the past 20 yrs more than 5,000 fossil specimens representing more than 200 species have been collected alone. An exceptional specimen preservation found in Tlayúa has been attributed to restricted circulation of water resulting in an anaerobic and/or hypersaline environment, coupled with the general absence of infaunal species. There were periods when the deposition site supported a rich planktontic community. Large quantities of calcareous ooze were produced, resulting in rapid burial of the organisms. The presence of diagnostic terrestrial and freshwater organisms, including arachnids, insects, lizards, and chelonians, along with typical marine fauna, suggests that Tlayúa lagoon had periodic freshwater inflow, in addition to the strong marine, lagoonal, and reefal influence. Some organisms were transported into the

Cosmic Spider is Good Mother

NASA Astrophysics Data System (ADS)

2006-04-01

Hanging above the Large Magellanic Cloud (LMC) - one of our closest galaxies - in what some describe as a frightening sight, the Tarantula nebula is worth looking at in detail. Also designated 30 Doradus or NGC 2070, the nebula owes its name to the arrangement of its brightest patches of nebulosity that somewhat resemble the legs of a spider. This name, of the biggest spiders on Earth, is also very fitting in view of the gigantic proportions of the celestial nebula - it measures nearly 1,000 light years across! ESO PR Photo 11/06 ESO PR Photo 13b/06 Tarantula's Central Cluster, R136 The Tarantula nebula is the largest emission nebula in the sky and also one of the largest known star-forming regions in all the Milky Way's neighbouring galaxies. Located about 170,000 light-years away, in the southern constellation Dorado (The Swordfish), it can be seen with the unaided eye. As shown in this image obtained with the FORS1 multi-mode instrument on ESO's Very Large Telescope, its structure is fascinatingly complex, with a large number of bright arcs and apparently dark areas in between. Inside the giant emission nebula lies a cluster of young, massive and hot stars, denoted R 136, whose intense radiation and strong winds make the nebula glow, shaping it into the form of a giant arachnid. The cluster is about 2 to 3 million years old, that is, almost from 'yesterday' in the 13.7 billion year history of the Universe. Several of the brighter members in the immediate surroundings of the dense cluster are among the most massive stars known, with masses well above 50 times the mass of our Sun. The cluster itself contains more than 200 massive stars. ESO PR Photo 11/06 ESO PR Photo 13c/06 The Stellar Cluster Hodge 301 In the upper right of the image, another cluster of bright, massive stars is seen. Known to astronomers as Hodge 301, it is about 20 million years old, or about 10 times older than R136. The more massive stars of Hodge 301 have therefore already exploded as

First Report of the Fig Cyst Nematode, Heterodera fici Kirjanova, on Fig Tree, Ficus carica, in Ontario, Canada.

PubMed

Sun, Fengcheng; Henry, Neil; Yu, Qing

2017-06-01

-682) µm, width = 395.3 ± 40.9 (366-442) µm, and length/width ratio = 1.3 ± 0.2 (1.3-1.7) µm. The morphometric characters of the vulval cone were fenestral length = 57.3 ± 2.9 (54-59) µm, fenestral width = 35.3 ± 4 (33-40) µm, and vulval slit = 50.7 ± 1.2 (50-52) µm. Second-stage juveniles tapering posteriorly (Fig. 1C). Stylet well developed, basal knobs rounded, directed slightly anteriorly (Fig. 1D). Tail tapering, with hyaline terminal about half of tail length (Fig. 1E). Second-stage juveniles ( n = 16) showed the following morphometric characters: body length = 440.9 ± 20 (408-470) µm, a = 20.3 ± 2.3 (16.9-24), b = 2.7 ± 0.3 (2.3-3.3), c = 8.1 ± 0.6 (7.3-9.3), c' = 3.8 ± 0.3 (3.1-4.3), stylet length = 23.2 ± 0.4 (23-24) µm, anterior end to median bulb = 71.8 ± 4.5 (65-79) µm; maximum body width = 21.9 ± 2 (17-25) µm; body width at anus = 14.4 ± 1.5 (12-17) µm, tail length = 54.6 ± 2.9 (50-60) µm, and hyaline part of tail = 23.7 ± 2.9 (19-28) µm. These observations conform to the published descriptions of Heterodera fici Kirjanova (Kirjanova, 1954; Golden et al., 1988). The slides of the cyst vulval cone and juveniles were deposited in the Canadian National collection of Insects, Arachnids, and Nematodes (Accession no. 14851 to 14853 for the second stage juveniles and 14854-14855 for the cyst cones). For molecular analysis, DNA was extracted from individual juvenile ( n = 4) from different cysts. A 1,151-bp fragment of ribosomal DNA containing ITS1-5.8S-ITS2 region was amplified and sequenced using primers 18S (5'-TTGATTACGTCCCTGCCCTTT-3') and 26S (5'- TTTCACTCGCCGTTACTAAGG-3') (Vrain et al., 1992). The sequence was deposited into the GenBank database (Accession no. KY635986 and KY635987) and was compared with published sequences by means of BLAST search in the database (November 2016). The comparison revealed 99.0% to 100% similarity to the sequences of the same genomic region of H. fici from Iran (AF498385) and Georgia (AF274409

Portrait of a Dramatic Stellar Crib

NASA Astrophysics Data System (ADS)

2006-12-01

the Wide Field Imager on the 2.2-m MPG/ESO telescope located at La Silla, Chile, while studying the dark clouds in the region. Dark clouds are enormous clouds of gas and dust, with a mass surpassing a million times that of the Sun. They are very cold, with temperatures about -260 degrees Celsius, and are difficult to study because of the heavy walls of dust behind which they hide. Their study is however essential, as it is in their freezing wombs that stars are born. ESO PR Photo 50b/06 ESO PR Photo 50b/06 SN 1987A and the Honeycomb Nebula (WFI/2.2m) Observing in four different bands, the astronomers made a mosaic of the half-degree field of view of the instrument to obtain an image covering one square degree. With each individual image containing 64 million pixels, the resultant mosaic thus contained 4 times as many, or 256 million pixels! The observations were made in very good image quality, the 'seeing' being typically below 1 arcsecond. The image is based on data collected through four filters, including two narrow-band filters that trace hydrogen (red) and oxygen (green). The predominance of green in the Tarantula is a result of the younger, hotter stars in this region of the complex. It would be easy to get lost in the meanderings of the filamentary structures or get stuck in the web of the giant arachnid, as is easily experienced with the zoom-in feature provided on the associated photo page, and it is therefore difficult to mention all the unique objects to be discovered. Deserving closer attention perhaps is the area at the right-hand border of the Tarantula. It contains the remains of a star that exploded and was seen with the unaided eye in February 1987, i.e. almost 20 years ago. Supernova SN 1987A, as it is known, is the brightest supernova since the one observed by the German astronomer Kepler in 1604. The supernova is known to be surrounded by a ring, which can be distinguished in the image. A little to the left of SN 1987A, another distinctive feature