Miller, A D; Umina, P A; Weeks, A R; Hoffmann, A A
The wheat curl mite (WCM), Aceria tosichella Keifer, is a polyphagous eriophyoid mite and the primary vector of wheat streak mosaic virus (WSMV) and five other viral pathogens in cereals. Previous research using molecular markers and a series of laboratory experiments found A. tosichella in Australia to consist of two genetically distinct lineages, which have broad overlapping distributions and differ in their ability to transmit WSMV under controlled conditions. This pattern of transmission also appears to be apparent in the field, whereby a strong association between WSMV detection and a single WCM lineage has been detected. In this study, we conduct a population genetic analysis and provide information on the genetic structure of the Australian viruliferous WCM lineage. We assessed genetic differentiation of 16 WCM populations using nine microsatellite markers. Strong evidence for extensive gene flow and low genetic structuring throughout the Australian wheatbelt was evident, with an exception for Western Australian and far north Queensland populations that appear to be genetically isolated. The data also indicate genetic patterns consistent with an arrhenotokous parthenogenetic mode of reproduction. Implications of these findings are discussed with reference to the management of WCM and associated cereal pathogens in Australia and overseas.
The wheat curl mite, Aceria tosichella Keifer, transmits at least three harmful viruses, wheat streak mosaic virus (WSMV), high plains virus (HPV), and Triticum mosaic virus (TriMV) to wheat (Triticum aestivum L.) throughout the Great Plains. This virus complex is considered to be the most serious d...
The wheat curl mite (WCM), Aceria tosichella Keifer, is a major pest of cereals worldwide that also comprises a complex of at least 16 genetic lineages with divergent physiological traits, including host preference and specificity. The goal of this study was to test the extent to which host-plant sp...
The wheat curl mite (WCM), Aceria tosichella Keifer, is a major pest of cereals worldwide. It is also a complex of well-defined genetic lineages with divergent physiological traits, which has not been accounted for in applied contexts. The aims of the study were to model the thermal niches of the two most pestiferous WCM lineages, designated MT-1 and MT-8, and to assess the extent to which temperature determines the distribution of these lineages. WCM population dynamics were modeled based on thermal niche data from March to November on the area of Poland (>311,000 km2). The most suitable regions for population development were predicted and compared to empirical field abundance data. Congruence between modeled parameters and field data for mite presence were observed for both WCM lineages although congruence between modeled thermal suitability and mite field abundance was observed only for MT-8. Thermal niche data for MT-1 and MT-8 provide biological insights and aid monitoring and management of WCM and the plant viruses it vectors. The presented models accurately estimate distributions of WCM and can be incorporated into management strategies for both current and predicted climate scenarios. PMID:27123590
Skoracka, Anna; Lewandowski, Mariusz; Rector, Brian G; Szydło, Wiktoria; Kuczyński, Lechosław
The wheat curl mite (WCM), Aceria tosichella Keifer, is a major pest of cereals worldwide that also comprises a complex of at least 16 genetic lineages with divergent physiological traits, including host associations and specificity. The goal of this study was to test the extent to which host-plant species and landscape spatial variation influence WCM presence and population density across the entire area of Poland (>311,000 km2). Three important findings arose from the results of the study. (1) The majority of WCM lineages analyzed exhibited variation in patterns of prevalence and/or population density on both spatial and host-associated scales. (2) Areas of occurrence and local abundance were delineated for specific WCM lineages and it was determined that the most pestiferous lineages are much less widespread than was expected, suggesting relatively recent introductions into Poland and the potential for further spread. (3) The 16 WCM lineages under study assorted within four discrete host assemblages, within which similar host preferences and host infestation patterns were detected. Of these four groups, one consists of lineages associated with cereals. In addition to improving basic ecological knowledge of a widespread arthropod herbivore, the results of this research identify high-risk areas for the presence of the most pestiferous WCM lineages in the study area (viz. the entirety of Poland). They also provide insight into the evolution of pest species of domesticated crops and facilitate testing of fundamental hypotheses about the ecological factors that shape this pest community.
Lewandowski, Mariusz; Rector, Brian G.; Szydło, Wiktoria
The wheat curl mite (WCM), Aceria tosichella Keifer, is a major pest of cereals worldwide that also comprises a complex of at least 16 genetic lineages with divergent physiological traits, including host associations and specificity. The goal of this study was to test the extent to which host-plant species and landscape spatial variation influence WCM presence and population density across the entire area of Poland (>311,000 km2). Three important findings arose from the results of the study. (1) The majority of WCM lineages analyzed exhibited variation in patterns of prevalence and/or population density on both spatial and host-associated scales. (2) Areas of occurrence and local abundance were delineated for specific WCM lineages and it was determined that the most pestiferous lineages are much less widespread than was expected, suggesting relatively recent introductions into Poland and the potential for further spread. (3) The 16 WCM lineages under study assorted within four discrete host assemblages, within which similar host preferences and host infestation patterns were detected. Of these four groups, one consists of lineages associated with cereals. In addition to improving basic ecological knowledge of a widespread arthropod herbivore, the results of this research identify high-risk areas for the presence of the most pestiferous WCM lineages in the study area (viz. the entirety of Poland). They also provide insight into the evolution of pest species of domesticated crops and facilitate testing of fundamental hypotheses about the ecological factors that shape this pest community. PMID:28099506
The wheat curl mite (WCM; Aceria tosichella) is a major pest of cereals worldwide. It is also a complex of well-defined genetic lineages with divergent physiological traits, which has not been accounted for in applied contexts. The aims of the study were to model the thermal niches of the two most p...
Melo, José W da S; Domingos, Cleiton A; Gondim, Manoel G C; Moraes, Gilberto J de
Mites of the genus Euseius are generally considered specialist as pollen feeders. Euseius alatus DeLeon is one of the six species of phytoseiid mites most commonly found on coconut plants in northeast Brazil associated with Aceria guerreronis Keifer. Although the morphology of E. alatus does not favor the exploitation of the meristematic area of the fruit inhabited by A. guerreronis, the predator may have some role in the control of this eriophyid during the dispersion process. The objective of this work was to evaluate the development and reproduction of E. alatus on the following diets: A. guerreronis, Ricinus communis pollen (Euphorbiaceae), and Tetranychus urticae Koch (Tetranychidae) + R. communis pollen + honey solution 10%. Euseius alatus developed slightly faster and had slightly higher oviposition rate when feeding on the diet composed of T. urticae + pollen + honey. However, life table parameters were very similar on all diets, suggesting that E. alatus may contribute in reducing the population of A. guerreronis in the field.
Oliveira, D C; de Moraes, G J; Dias, C T S
The coconut mite, Aceria guerreronis Keifer, is one of the main pests of coconut palms (Cocos nucifera) in northeastern Brazil. The objective of this study was to evaluate the levels of the coconut mite and other mites on coconut palms in the state of São Paulo and to estimate the possible role of predatory mites in the control of this pest. The effect of cultivated genotypes and sampling dates on the mite populations was also estimated. We sampled attached fruits, leaflets, inflorescences, and fallen fruits. The coconut mite was the main phytophagous mite found on attached and fallen fruits, with average densities of 110.0 and 20.5 mites per fruit, respectively. The prevalent predatory mites on attached and fallen fruits were Proctolaelaps bulbosus Moraes, Reis & Gondim Jr. and Proctolaelaps bickleyi (Bram), both Melicharidae. On leaflets, the tenuipalpids Brevipalpus phoenicis (Geijsks) and Tenuipalpus coyacus De Leon and the tetranychid Oligonychus modestus (Banks) were the predominant phytophagous mites. On both leaflets and inflorescences, the predominant predatory mites belonged to the Phytoseiidae. Neoseiulus baraki (Athias-Henriot) and Neoseiulus paspalivorus (De Leon), predators widely associated with the coconut mite in northeastern Brazil and several other countries, were not found. The low densities of the coconut mite in São Paulo could be related to prevailing climatic conditions, scarcity of coconut plantations (hampering the dispersion of the coconut mite between fields), and to the fact that some of the genotypes cultivated in the region are unfavorable for its development.
Wheat streak mosaic virus (WSMV) is the most economically important wheat virus in the Great Plains region of USA. WSMV is the type species of the genus Tritimovirus in the family Potyviridae, and is transmitted by the wheat curl mite, Aceria tosichella Keifer. Previously, we reported that WSMV P1 f...
Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) are transmitted by the wheat curl mite (WCM, Aceria tosichella Keifer). Previous work has shown that different mite genotypes transmit TriMV at different rates. The objective of this research was to determine if mite genotypes differ...
Triticum mosaic virus (TriMV) is a recently discovered virus infecting wheat (Triticum aestivum L.) in the Great Plains region of the United States. It is transmitted by wheat curl mites (Aceria tosichella Keifer) which also transmit Wheat streak mosaic virus (WSMV) and Wheat mosaic virus. In a gree...
Triticum mosaic virus (TriMV) is a newly discovered virus found infecting wheat (Triticum aestivum L.) in Kansas. This study was conducted to determine if the wheat curl mite (WCM, Aceria tosichella Keifer) and the bird cherry oat aphid (Rhopalosiphum padi L. ) could transmit TriMV. Using diffe...
Wheat streak mosaic virus (WSMV), Triticum mosaic virus, and Wheat mosaic virus, all vectored by the wheat curl mite Aceria tosichella Keifer, frequently cause devastating losses to winter wheat production throughout the central and western Great Plains. Resistant 'Mace' and 'RonL' are commercially ...
Wheat streak mosaic virus (WSMV), vectored by the wheat curl mite Aceria tosichella Keifer, is a major limiting factor in wheat production in the Texas Panhandle. It is the most frequently encountered virus in the region, affecting both shoot and root biomass, and consequently it can drastically red...
Substitutions in the amino-terminal region of Wheat streak mosaic virus (WSMV) HC-Pro were evaluated for effects on transmission by the wheat curl mite (Aceria tosichella Keifer). Alanine substitution at cysteine residues 16, 46 and 49 abolished vector transmission. Although alanine substitution a...
Melo, J W S; Lima, D B; Sabelis, M W; Pallini, A; Gondim, M G C
For the coconut mite, Aceria guerreronis Keifer, its host plant, the coconut palm, is not merely a source of food, but more generally a habitat to live in for several generations. For these minute organisms, finding a new plant is difficult and risky, especially because their main mode of dispersal is passive drifting with the wind and because they are highly specialized on their host plant. Consequently, the probability of landing on a suitable host is very low, let alone to land in their specific microhabitat within the host. How coconut mites manage to find their microhabitat within a host plant is still underexplored. We tested the hypothesis that they use volatile chemical information emanating from the plant to find a specific site within their host plants and/or use non-volatile plant chemicals to stay at a profitable site on the plant. This was investigated in a Y-tube olfactometer (i.e. under conditions of a directed wind flow) and on cross-shaped arenas (i.e. under conditions of turbulent air) that either allowed contact with odour sources or not. The mites had to choose between odours from specific parts (leaflet, spikelet or fruit) of a non-infested coconut plant and clean air as the alternative. In the olfactometer experiments, no mites were found to reach the upwind end of the Y-tube: <5 % of the mites were able to pass the bifurcation of the "Y". On the cross-shaped arenas, however, a large number of coconut mites was found only when the arm of the arena contained discs of fruit epidermis and contact with these discs was allowed. The results suggest that coconut mites on palm trees are not attracted to specific sites on the plant by volatile plant chemicals, but that they arrested once they contact the substrate of specific sites. Possibly, they perceive non-volatile chemicals, but these remain to be identified.
Monteiro, Vaneska B; Lima, Debora B; Gondim, Manoel G C; Siqueira, Herbert A A
Aceria guerreronis Keifer (Acari: Eriophyidae) is considered a major pest of the coconut (Cocos nucifera L.), and the use of pesticides is the current method to control it. However, no standard toxicological tests exist to select and assess the efficiency of molecules against the coconut mite. The aim of this study was to develop a methodology that allows for the evaluation of the relative toxicity of acaricides to A. guerreronis through rapid laboratory procedures. We confined A. guerreronis on arenas made out of coconut leaflets and tested two application methods: immersing the leaf fragments in acaricides and spraying acaricides on the leaf fragments under a Potter spray tower. In the latter application method, we sprayed leaf fragments both populated with and devoid of mites. We evaluated the comparative toxicity of two populations (Itamaracá and Petrolina, Pernambuco, Brazil) by spraying on leaflets without mites and submitted the mortality data to probit analysis after 24 h of exposure. No difference was observed in the LC50, regardless of whether the leaflets were immersed or sprayed with acaricide (abamectin, chlorfenapyr or fenpyroximate). The toxicity of chlorfenapyr and fenpyroximate did not differ, irrespective of whether it was applied directly to the leaflet or to the mite; however, the toxicity of abamectin was higher when applied directly to the mite. Chlorpyrifos and abamectin toxicities were lower for the Petrolina population than for the Itamaracá population. Immersing and spraying coconut leaflets can be used to assess the mortality of A. guerreronis under laboratory conditions.
Villavicencio, L E; Bethke, J A; Dahlke, B; Vander Mey, B; Corkidi, L
The aloe mite, Aceria aloinis Keifer, causes physiological and morphological alterations in species of Aloe L. We conducted three trials to evaluate the potential of various miticides for curative and preventive control of damage caused by A. aloinis. In the first trial, the efficacy of nine miticides against aloe mite damage was assessed without the removal of infected tissue in Aloe reitziiae Reynolds. Although significant reductions in the number of mites and eggs were found due to the treatments, miticide application did not reduce the amount of plant area damaged or damage severity. Once the plants are infected, the irreversible damage by aloe mite progresses. The second trial analyzed the effects of seven miticides on aloe mite damage on Aloe 'Goliath' plants in which the damaged tissue was removed. Reduced damage severity and mite number was observed in all treated plants. To determine if aloe mite damage could be prevented, the effects of six miticides with and without surfactant were tested on uninfected plants of Aloe spinosissima A. Berger in a third trial. Except for chlorfenapyr and fenazaquin, all treatments reduced plant damaged area, damage severity, and the number of mites 60 wk following three miticide applications. The severity index in the second and third trials suggested that all treated plants would be marketable. Our study demonstrated that there were miticides that were effective by contact (carbaryl), translaminar (spiromesifen), and systemic (spirotetramat) action, which can be used to cure and to prevent aloe mite plant damage alone or in combination with cultural practices. © 2014 Entomological Society of America.
Al-Shanfari, Abdulaziz; Hountondji, Fabien C C; Al-Zawamri, Hamid; Rawas, Hassan; Al-Mashiki, Yussef; de Moraes, Gilberto J; Moore, Dave; Gowen, Simon R
The coconut palm is an important crop in the sub arid coastal plain of Dhofar, Oman, for the high demand for its nut water and its use as ornamental plant. Damage of coconut fruits by the eriophyid mite Aceria guerreronis Keifer was first reported in that region in the late 1980s, but background information about the ecology of the pest in Oman was missing. Four surveys were conducted in different seasons from 2008 to 2009, to assess the distribution and prevalence of the coconut mite and its damage as well as the presence of natural enemies. Infestation by the coconut mite was conspicuous on most (99.7 %) palm trees, with 82.5 % damaged fruits. The average (± SE) density of coconut mites per fruit was 750 ± 56; this level of infestation led to the incidence of over 25 % of surface damage on more than half of the fruits. The mite appeared more abundant at the end of the cold season through the summer. No significant differences were observed between infestation levels on local varieties, hybrids and on dwarf varieties. Neoseiulus paspalivorus (De Leon), Cydnoseius negevi (Swirski & Amitai) and Amblyseius largoensis (Muma) were the predatory mites found under the bracts of over 30 % of the coconut fruits and on 68 % of the coconut trees. Considering all sampling dates and all varieties together, average (± SE) phytoseiid density was 1.4 ± 1.19 per fruit. Other mites found in the same habitat as A. guerreronis included the tarsonemids Steneotarsonemus furcatus De Leon and Nasutitarsonemus omani Lofego & Moraes. The pathogenic fungus Hirsutella thompsonii Fisher was rarely found infecting the coconut mite in Dhofar. Other fungal pathogens, namely Cordyceps sp. and Simplicillium sp., were more prevalent.
Melo, José Wagner S; Lima, Debora B; Pallini, Angelo; Oliveira, José Eudes M; Gondim, Manoel G C
The phytophagous mite Aceria guerreronis Keifer is an important pest of coconut worldwide. A promising method of control for this pest is the use of predatory mites. Neoseiulus baraki (Athias-Henriot) and Proctolaelaps bickleyi Bram are predatory mites found in association with A. guerreronis in the field. To understand how these predators respond to olfactory cues from A. guerreronis and its host plant, the foraging behavior of the predatory mites was investigated in a Y-tube olfactometer and on T-shaped arenas. The predators were subjected to choose in an olfactometer: (1) isolated parts (leaflet, spikelet or fruit) of infested coconut plant or clean air stream; (2) isolated parts of non-infested or infested coconut plant; and (3) two different plant parts previously shown to be attractive. Using T-shaped arenas the predators were offered all possible binary combinations of discs of coconut fruit epidermis infested with A. guerreronis, non-infested discs or coconut pollen. The results showed that both predators were preferred (the volatile cues from) the infested plant parts over clean air. When subjected to odours from different infested or non-infested plant parts, predators preferred the infested parts. Among the infested plant parts, the spikelets induced the greatest attraction to predators. On the arenas, both predators preferred discs of coconut fruits infested with A. guerreronis over every other alternative. The results show that both predators are able to locate A. guerreronis by olfactory stimuli. Foraging strategies and implications for biological control are discussed.
Lawson-Balagbo, L M; Gondim, M G C; de Moraes, G J; Hanna, R; Schausberger, P
Coconut is an important crop in tropical and subtropical regions. Among the mites that infest coconut palms, Aceria guerreronis Keifer is economically the most important. We conducted surveys throughout the coconut growing areas of Brazil. Samples were taken from attached coconuts, leaflets, fallen coconuts and inflorescences of coconut palms in 112 localities aiming to determine the occurrence and the distribution of phytophagous mites, particularly A. guerreronis, and associated natural enemies. Aceria guerreronis was the most abundant phytophagous mite followed by Steneotarsonemus concavuscutum Lofego & Gondim Jr. and Steneotarsonemus furcatus De Leon (Tarsonemidae). Infestation by A. guerreronis was recorded in 87% of the visited localities. About 81% of all predatory mites belonged to the family Phytoseiidae, mainly represented by Neoseiulus paspalivorus De Leon, Neoseiulus baraki Athias-Henriot and Amblyseius largoensis Muma; 12% were Ascidae, mainly Proctolaelaps bickleyi Bram, Proctolaelaps sp nov and Lasioseius subterraneus Chant. Neoseiulus paspalivorus and N. baraki were the most abundant predators on attached coconuts. Ascidae were predominant on fallen coconuts, while A. largoensis was predominant on leaflets; no mites were found on branches of inflorescences. Leaflets harboured higher mite diversity than the attached coconuts. Mite diversity was the highest in the state Pará and on palms surrounded by seasonal forests and Amazonian rain-forests. Neoseiulus paspalivorus, N. baraki and P. bickleyi were identified as the most promising predators of A. guerreronis. Analyses of the influence of climatic factors revealed that dry ambient conditions favour the establishment of A. guerreronis. Neoseiulus paspalivorus and N. baraki have differing climatic requirements; the former being more abundant in warm and dry areas, the latter prevailing in moderately tempered and humid areas. We discuss the significance of our findings for natural and biological
Host-specificity is the most important criterion for biological control agents (BCAs) and is particularly important for BCAs of invasive grasses that are close relatives of grass crop species. Plant-feeding mites in the family Eriophyidae are often highly host-specific. A study was conducted on th...
The petition submitted to USDA-APHIS Technical Advisory Group on Dec. 16, 2004 (No. 04-06) indicated that the eriophyid mite, Aceria salsolae, will infest all the weedy Salsola species (Russian thistle; tumbleweeds) in the Salsola kali section (S. tragus, S. collina, S. paulsenii, S. australis (=typ...
Navia, D; de Moraes, G J; Roderick, G; Navajas, M
Over the past 30 years the coconut mite Aceria guerreronis Keifer has emerged as one of the most important pests of coconut and has recently spread to most coconut production areas worldwide. The mite has not been recorded in the Indo-Pacific region, the area of origin of coconut, suggesting that it has infested coconut only recently. To investigate the geographical origin, ancestral host associations, and colonization history of the mite, DNA sequence data from two mitochondrial and one nuclear region were obtained from samples of 29 populations from the Americas, Africa and the Indo-ocean region. Mitochondrial DNA 16S ribosomal sequences were most diverse in Brazil, which contained six of a total of seven haplotypes. A single haplotype was shared by non-American mites. Patterns of nuclear ribosomal internal transcribed spacer (ITS) variation were similar, again with the highest nucleotide diversity found in Brazil. These results suggest an American origin of the mite and lend evidence to a previous hypothesis that the original host of the mite is a non-coconut palm. In contrast to the diversity in the Americas, all samples from Africa and Asia were identical or very similar, consistent with the hypothesis that the mite invaded these regions recently from a common source. Although the invasion routes of this mite are still only partially reconstructed, the study rules out coconut as the ancestral host of A. guerreronis, thus prompting a reassessment of efforts using quarantine and biological control to check the spread of the pest.
Sousa, André Silva Guimarães; Argolo, Poliane Sá; Gondim, Manoel Guedes Correa; de Moraes, Gilberto José; Oliveira, Anibal Ramadan
The coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), is one of the main coconut pests in the American, African and parts of the Asian continents, reaching densities of several thousand mites per fruit. Diagrammatic scales have been developed to standardize the estimation of the population densities of A. guerreronis according to the estimated percentage of damage, but these have not taken into account the possible effect of fruit age, although previous studies have already reported the variation in mite numbers with fruit age. The objective of this study was to re-construct the relation between damage and mite density at different fruit ages collected in an urban coconut plantation containing the green dwarf variety ranging from the beginning to nearly the end of the infestation, as regularly seen under field conditions in northeast Brazil, in order to improve future estimates with diagrammatic scales. The percentage of damage was estimated with two diagrammatic scales on a total of 470 fruits from 1 to 5 months old, from a field at Ilhéus, Bahia, Brazil, determining the respective number of mites on each fruit. The results suggested that in estimates with diagrammatic scales: (1) fruit age has a major effect on the estimation of A. guerreronis densities, (2) fruits of different ages should be analyzed separately, and (3) regular evaluation of infestation levels should be done preferably on fruits of about 3-4 months old, which show the highest densities.
Complementary description of Colomerus novahebridensis Keifer (Acari, Eriophyidae), with a discussion about the constitution of the genus and its economic importance, and a tentative key to Colomerus Newkirk & Keifer species
Chandrapatya, Angsumarn; Konvipasruang, Ploychompoo; Flechtmann, Carlos H. W.; de Moraes, Gilberto J.
Abstract Colomerus Newkirk & Keifer, 1971 is an eriophyid genus described by Newkirk and Keifer about 43 years ago, that contains species from all continents, except Antarctica. They live mostly on dicotyledonous plants. Colomerus novahebridensis Keifer, 1977 was described from coconut (Cocos nucifera L., Arecaceae) fruits from Vanuatu. A description of a Thai population of this species is given in this paper. A revised characterization of Colomerus and a dichotomous key for the separation of the species presently considered to belong to this genus are provided, and a consideration about the importance of Colomerus species is presented. PMID:25152678
Complementary description of Colomerus novahebridensis Keifer (Acari, Eriophyidae), with a discussion about the constitution of the genus and its economic importance, and a tentative key to Colomerus Newkirk & Keifer species.
Chandrapatya, Angsumarn; Konvipasruang, Ploychompoo; Flechtmann, Carlos H W; de Moraes, Gilberto J
Colomerus Newkirk & Keifer, 1971 is an eriophyid genus described by Newkirk and Keifer about 43 years ago, that contains species from all continents, except Antarctica. They live mostly on dicotyledonous plants. Colomerus novahebridensis Keifer, 1977 was described from coconut (Cocos nucifera L., Arecaceae) fruits from Vanuatu. A description of a Thai population of this species is given in this paper. A revised characterization of Colomerus and a dichotomous key for the separation of the species presently considered to belong to this genus are provided, and a consideration about the importance of Colomerus species is presented.
Menon, Pratibha; Joshi, Sushila; Ramamurthy, Vilayanoor Venkataraman
A new species of Eriophyidae (Acari: Prostigmata: E riophyoidea) mite, Aceria tripuraensis n. sp., is described from the closed bud galls of Hibiscus macrophyllus Roxb. ex Hornem. (Malvaceae) in India. Aceria tripuraensis n. sp. is distinguished by having a prodorsal shield with distinct rounded lobes on the postero-lateral margins and two pairs of submedian lines. The tarsal solenidia with unusual transverse sculptures, are 2.5x longer than the empodia. Twenty Aceria species are now known to inhabit malvaceous plant hosts and those are listed here along with type localities and host plant details. A key to all known species of Aceria recorded from Hibiscus spp. is also provided.
Ripka, Géza; Sánchez, Iňigo
A new species of eriophyoid mite, Aceria pycnocomi sp. nov., associated with Pycnocomon rutifolium (Dipsacaceae), is described and illustrated from Spain. Morphological differences distinguishing this new species from similar Aceria species are discussed. The female, male and nymph of Aceria eucricotes (Nalepa, 1892) and Aceria kuko (Kishida, 1927) are redescribed and illustrated from Spain and Hungary, respectively; both were collected from Lycium spp. (Solanaceae). Morphological differences distinguishing these two species are discussed.
Supplementary description of Novophytoptus stipae Keifer 1962 (Acariformes, Eriophyoidea) with LT-SEM observation on mites from putativley conspecific populations: cryptic speciation or polyphagy of novophytoptines
Supplementary descriptions of an infrequently encountered species Novophytoptus stipae Keifer 1962 (Eriophyoidea, Phytoptidae) from Achnatherum speciosum (Poaceae) based on topotypes recovered from dry plant material from California is given. Comparison of topotypes of N. stipae with fresh Novophyto...
Thirty-two Canada thistle infestations in eastern Colorado and Wyoming and western Nebraska were surveyed in 2004 for the eriophyid mite Aceria anthocoptes (Nal.). Mites were abundant at 41% of the sites, present in lesser numbers at 53% of the sites, and no mites were found at 6% of the sites. In 2...
The study examines the role of the mango bud mite, Aceria mangiferae, in carrying Fusarium mangiferae’s conidia, vectoring them into the penetration sites and assisting fungal penetration and dissemination. Conidia that were exposed to a green fluorescent protein (gfp)-marked isolate of F. mangifer...
Centaurea solstitialis (yellow starthistle) is an annual noxious weed that currently infests millions of acres of rangelands, non-cultivated and natural areas in the Western USA. It displaces native plant communities reducing plant diversity and forage production for livestock and wildlife. Aceria s...
Yellow starthistle (Centaurea solstitialis) is an invasive annual weed in the western USA that is native to the Mediterranean Region and is a target for classical biological control. Aceria solstitialis is an eriophyid mite that has been found exclusively in association with yellow starthistle in I...
Aceria paederiae (Nalepa) infesting leaves of Paederia foetida L. (Family Rubiaceae) in Thailand, Hong Kong and Singapore is reported for the first time. The mite induces small, round galls on both leaf surfaces. The complete descriptions of both males and females, including line drawings and SEM ...
Tessa R. Grasswitz
The biology, recognition, and impact of eriophyid mites (with emphasis on species associated with trees and shrubs) are briefly reviewed. A case study of a leaf-curling eriophyid mite (Aceria sp.) attacking New Mexico olive (Forestiera pubescens Nutt. var. pubescens) is used to illustrate the complexities of developing control strategies for eriophyids in native plant...
The eriophyid mite, Aceria salsolae attacks several species of invasive alien tumbleweeds, including Salsola tragus, S. collina, S. paulsenii and S. australis, in North America. Previous laboratory experiments to determine host specificity of the mite indicated that it could sometimes persist and m...
Leiva, Sergio; Fernandez, Nestor; Theron, Pieter; Rollard, Christine
Abstract A new species, Agistemus aimogastaensis, is described with the aid of optical and Scanning Electron Microscopy. This mite is an important predator of two eriophyid mites (Aceria oleae and Oxycenus maxwelli) in olive orchards (Olea europaea, variety Arauco) in La Rioja Province. The problems related to eriophyids in olive orchards in Argentina are highlighted and photos of the damage on leaves and fruit are included. PMID:23825448
Leiva, Sergio; Fernandez, Nestor; Theron, Pieter; Rollard, Christine
A new species, Agistemus aimogastaensis, is described with the aid of optical and Scanning Electron Microscopy. This mite is an important predator of two eriophyid mites (Aceria oleae and Oxycenus maxwelli) in olive orchards (Olea europaea, variety Arauco) in La Rioja Province. The problems related to eriophyids in olive orchards in Argentina are highlighted and photos of the damage on leaves and fruit are included.
Villanueva, Raul T; Childers, Carl C
Development and reproduction of Iphiseiodes quadripilis (Banks) were evaluated on single food diets of pollen (Malephora crocea Jacquin [ice plant] or Quercus sp. [oak]), spider mites, [Eutetranychus banksi (McGregor) or Panonychus citri (McGregor) (Acari: Tetranychidae)], or the citrus rust mite Phyllocoptruta oleivora (Ashmead) (Acari: Eriophyidae). Experiments were conducted in an environmental chamber at 28 degrees +/- 1 degrees C, 14:10 (L:D) daylength, and 45% RH. I. quadripilis completed development and laid viable eggs that subsequently hatched on diets of either ice plant or oak pollen or eggs and motile stages of E. banksi. P. citri was acceptable as prey, but survival of larvae to adults was only 36%, whereas survival on E. banksi, ice plant pollen, and oak pollen was 48, 60, and 68%, respectively. The webbing produced by P. citri seemed to inhibit foraging behavior of I. quadripilis larvae and nymphs. Larvae of I. quadripilis developed only to the second nymphal instar on a diet of P. oleivora alone or water alone. Starved I. quadripilis females and deutonymphs were observed preying on the pink citrus rust mite, Aculops pelekassi (Keifer) (Eriophyidae). During 4-min observation trials, two series of I. quadripilis fed on 1.8 +/- 0.47 and 3.5 +/- 0.45 A. pelekassi motile stages after being starved for 6 and 24 h, respectively. I. quadripilis females did not prey on P. oleivora in arenas containing both rust mite species.
Chuang, Wen-Po; Rojas, Lina Maria Aguirre; Khalaf, Luaay Kahtan; Zhang, Guorong; Fritz, Allan K; Whitfield, Anna E; Smith, C Michael
The wheat curl mite, Aceria tosichella Keifer, (WCM) is a global pest of bread wheat that reduces yields significantly. In addition, WCM carries Wheat streak mosaic virus (WSMV, family Potyviridae, genus Tritimovirus), the most significant wheat virus in North America; High Plains wheat mosaic virus (HPWMoV, genus Emaravirus, formerly High plains virus); and Triticum mosaic virus (TriMV, family Potyviridae, genus Poacevirus). Viruses carried by WCM have reduced wheat yields throughout the U.S. Great Plains for >50 yr, with average yield losses of 2-3% and occasional yield losses of 7-10%. Acaricides are ineffective against WCM, and delayed planting of winter wheat is not feasible. Five wheat breeding lines containing Cmc4, a WCM resistance gene from Aegilops tauschii, and Wsm2, a WSMV resistance gene from wheat germplasm CO960293-2 were selected from the breeding process and assessed for phenotypic reaction to WCM feeding, population increase, and the degree of WSMV, HPWMoV, and TriMV infection. Experiments determined that all five lines are resistant to WCM biotype 1 feeding and population increase, and that two breeding lines contain resistance to WSMV, HPWMoV, and TriMV infection as well. These WCM-, WSMV-, HPWMoV-, and TriMV-resistant genotypes can be used improve management of wheat yield losses from WCM-virus complexes.
Stoeva, Atanaska; Harizanova, Vili; de Lillo, Enrico; Cristofaro, Massimo; Smith, Lincoln
Centaurea solstitialis (yellow starthistle, Asteraceae) is an invasive annual weed in the western USA that is native to the Mediterranean Region and is a target for classical biological control. Aceria solstitialis is an eriophyid mite that has been found exclusively in association with Ce. solstitialis in Italy, Greece, Turkey and Bulgaria. The mite feeds on leaf tissue and damages bolting plants, causing stunting, witch's broom and incomplete flower development. Field experiments and laboratory no-choice and two-way choice experiments were conducted to assess host plant specificity of the mite in Bulgaria. Mites showed the highest degree of host specificity in the field and lowest in the no-choice experiments. In the field, highest densities of mites occurred on Ce. solstitialis and Ce. cyanus (bachelor's button), and either no mites or trace numbers occurred on the other test plants: Ce. diffusa (diffuse knapweed), Carthamus tinctorius (safflower) and Cynara scolymus (artichoke). In no-choice experiments, mites persisted for 60 days on Ce. diffusa, Ce. cyanus, Ce. solstitialis, Ca. tinctorius and Cy. scolymus, whereas in two-way choice experiments mites persisted on 25% of Cy. scolymus plants for 60 days and did not persist on Ca. tinctorius beyond 40 days. The eight other species of plants that were tested in the laboratory were less suitable for the mite. These results suggest that although A. solstitialis can persist on some nontarget plants for as long as 60 days in the laboratory, it appears to be much more specific under natural conditions, and warrants further evaluation as a prospective biological control agent.
Oliveira, Natália N F C; Galvão, Andreia S; Amaral, Ester A; Santos, Auderes W O; Sena-Filho, José G; Oliveira, Eugenio E; Teodoro, Adenir V
The coconut mite, Aceria guerreronis (Acari: Eriophyidae), is a major tropical pest of coconut. Here, we assessed the chemical profiles and the potential use of babassu, degummed soybean, and coconut oils to control A. guerreronis as well as their side-effects on the predatory mite Neoseiulus baraki (Acari: Phytoseiidae), a key natural enemy of the coconut mite. Babassu and coconut oils had similar fatty acids chemical profiles. All vegetable oils showed toxicity to A. guerreronis; degummed soybean oil exhibited the highest toxicity (LC50 = 0.15 µL/cm(2)). Although all oils were less toxic to N. baraki, their potential to attract/repel this predatory mite differed. Whereas N. baraki females were unresponsive to coconut oil at both concentrations (i.e., LC50 and LC99 estimated for A. guerreronis), irrespective of exposure period (i.e., 1 or 24 h), the babassu oil repelled the predator, independent of exposure period, when applied at its LC99 (1.48 µL/cm(2)). Intriguingly, this oil also exhibited attractiveness to N. baraki 24 h after exposure when applied at its LC50 (0.26 µL/cm(2)). A similar attractiveness pattern was recorded 24 h after N. baraki was exposed to degummed soybean oil at both concentrations tested (LC50 = 0.15 µL/cm(2); LC99 = 1.39 µL/cm(2)). However, N. baraki was repelled by degummed soybean oil at its LC50 after 1 h of exposure. Therefore, the present study demonstrated that all the vegetable oils used here had higher toxicity to the coconut mite and considerable selectivity to the predator N. baraki, indicating they are promising tools that can potentially be included in management programs to control A. guerreronis in commercial coconut plantations.
Wheat streak mosaic (WSM) caused by Wheat streak mosaic virus, which is transmitted by the wheat curl mite (Aceria tosichella), is a major yield-limiting disease in the Texas High Plains. In addition to its impact on grain production, the disease reduces water-use efficiency by affecting root develo...
High Plains disease of wheat and maize emerged in the United States in 1993 and its distribution has expanded in subsequent years. Wheat mosaic virus (WMoV), transmitted by eriophyid wheat curl mites (Aceria tosichella) is the causal agent of disease. WMoV and other members of the genus Emaravirus...
Wheat curl mites (WCM; Aceria tosichella) transmit Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), and Wheat mosaic virus (WMoV) to wheat (Triticum aestivum L.) in the Great Plains region of the United States. These viruses can be detected in single, double, or triple combinations i...
Background. The wheat curl mite (Aceria tosichella) is a global pest of wheat and other cereals, causing losses by direct damage as well as transmission of plant pathogens such as wheat streak mosaic virus. This mite has long been considered to be a single, highly polyphagous species, capable of co...
The wheat curl mite (WCM), Aceria tosichella, is an important pest of wheat and other cereal crops that transmits wheat streak mosaic virus and several other plant viruses. WCM has long been considered a single polyphagous species, but recent studies in Poland revealed a complex of genetically disti...
The taxonomy of two economically important eriophyoid species, Aceria tosichella (wheat curl mite, WCM) and A. tulipae (dry bulb mite, DBM), was confounded in the world literature until the late 20th century due to their morphological similarity and ambiguous data from plant-transfer and virus-trans...
Mukwevho, Ludzula; Simelane, David; Olckers, Terence
The flower-galling mite Aceria lantanae (Cook) (Trombidiformes: Eriophyidae) was released for the biological control of Lantana camara L. (Verbenaceae) in South Africa in 2007, but has displayed variable and patchy establishment throughout the weed's range. Surveys were undertaken in 2013-2014, both seasonally and during the mite's peak infestation periods, to determine the influence of climatic factors on its performance. Although there were seasonal differences in the percentages of mite-infested inflorescences, these did not differ significantly between altitudinal zones. There were also no significant relationships between the percentages of mite-infested inflorescences and either of annual rainfall, temperature or relative humidity. A field inoculation trial revealed significant differences between 10 common South African L. camara varieties in their susceptibility to A. lantanae. Only three varieties displayed appreciable susceptibility (50-61% of inflorescences infested), whereas six displayed only slight to moderate susceptibility (8-21%) and one displayed a lack of susceptibility (no infestation). These data support the contention that differential varietal susceptibility and not climate is responsible for the variable performance of A. lantanae on L. camara in South Africa. Complementing the current biotype of A. lantanae, originally sourced from Florida (USA), with other biotypes from different L. camara genotypes in Central and South America could increase the mite's impact on the weed.
Murugan, M; Sotelo Cardona, P; Duraimurugan, P; Whitfield, A E; Schneweis, D; Starkey, S; Smith, C M
The majority of plant viruses are dependent on arthropod vectors for spread between plants. Wheat streak mosaic virus (family Potyviridae, genus Tritimovirus, WSMV) is transmitted by the wheat curl mite, Aceria tosichella Keifer, and this virus and vector cause extensive yield losses in most major wheat (Triticum aestivum L.)-growing regions of the world. Many cultivars in use are susceptible to this vector-virus complex, and yield losses of 10-99% have been documented. wheat curl mite resistance genes have been identified in goat grass, Aegilops tauschii (Coss) Schmal., and transferred to hexaploid wheat, but very few varieties contain effectively wheat curl mite resistance, due to virulent wheat curl mite populations. However, wheat curl mite resistance remains an effective strategy to reduce losses due to WSMV. The goal of our project was to identify the most effective, reproducible, and rapid method for assessing wheat curl mite resistance. We also wanted to determine whether mite resistance is affected by WSMV infection, because the pathogen and pest commonly occur together. Single and group wheat curl mite infestations produced similar amounts of leaf rolling and folding on wheat curl mite-susceptible wheat varieties that were independent of initial wheat curl mite infestation. This finding will allow accurate, efficient, large-scale screening of wheat germplasm for wheat curl mite resistance by infesting plants with sections of wheat leaf tissue containing mixed stages of wheat curl mite. The wheat curl mite-resistant breeding line 'OK05312' displayed antibiosis (reduced wheat curl mite population development). The effect of WSMV infection on wheat curl mite reproduction was genotype-dependent. Mite populations increased on infected wheat curl mite- and WSMV-susceptible plants compared with uninfected plants, but WSMV infection had no significant effect on wheat curl mite populations on resistant plants. OK05312 is a strong source of wheat curl mite
Soika, Grażyna; Gol, Ali; Honarmand, Arash; Wozińska, Anna; Sadeghi, Hussein
Four species of eriophyoid mites are recorded from Iran, of which three represent new records and the other is a new species. These species are: Brevulacus salicinus n. sp. (Diptilomiopidae), found on Salix sp. (Salicaceae); Aceria wallichianae Keifer, 1975 from Ulmus minor (Ulmaceae); Aceria granulata Carmona, 1972 from Verbascum spp. (Scrophulariaceae) and Tegnacus unicornutus Pye, 2012 from Carpinus betulus (Betulaceae). Each of these species are illustrated and provided with data regarding their distribution and host plants.
Negloh, Koffi; Hanna, Rachid; Schausberger, Peter
Neoseiulus neobaraki and N. paspalivorus are amongst the most common phytoseiid predators of coconut mite, Aceria guerreronis, found in the spatial niche beneath coconut fruit bracts. Both predators may occur on the same coconut palms in Benin and Tanzania and are therefore likely to interact with each other. Here, we assessed cannibalism and intraguild predation (IGP) of the two predators in the absence and presence of their primary prey A. guerreronis. In the absence of the shared extraguild prey, A. guerreronis, N. neobaraki killed 19 larvae of N. paspalivorus per day and produced 0.36 eggs/female/day, while the latter species killed only 7 larvae of the former and produced 0.35 eggs/female/day. Presence of A. guerreronis only slightly decreased IGP by N. neobaraki but strongly decreased IGP by N. paspalivorus, which consumed 4-7 times less IG prey than N. neobaraki. Resulting predator offspring to IG prey ratios were, however, 4-5 times higher in N. paspalivorus than N. neobaraki. Overall, provision of A. guerreronis increased oviposition in both species. In the cannibalism tests, in the absence of A. guerreronis, N. neobaraki and N. paspalivorus consumed 1.8 and 1.2 conspecific larvae and produced almost no eggs. In the presence of abundant herbivorous prey, cannibalism dramatically decreased but oviposition increased in both N. neobaraki and N. paspalivorus. In summary, we conclude that (1) N. neobaraki is a much stronger intraguild predator than N. paspalivorus, (2) cannibalism is very limited in both species, and (3) both IGP and cannibalism are reduced in the presence of the common herbivorous prey with the exception of IGP by N. neobaraki, which remained at high levels despite presence of herbivorous prey. We discuss the implications of cannibalism and IGP on the population dynamics of A. guerreronis and the predators in view of their geographic and within-palm distribution patterns.
Kiedrowicz, Agnieszka; Rector, Brian G; Lommen, Suzanne; Kuczyński, Lechosław; Szydło, Wiktoria; Skoracka, Anna
Dry bulb mite (DBM), Aceria tulipae, is an economically important mite with a worldwide distribution and a broad host range. As a generalist, it is the most important eriophyoid mite attacking bulbous plants such as garlic, onion and tulip. To date, DBM has been recorded on host plants belonging to the families Liliaceae, Amaryllidaceae, Melanthiaceae and Asparagaceae. However, a precise understanding of DBM host range is lacking as it is largely based on casual records of mites on plants, some of which may include accidental hosts. Moreover, the possible existence of cryptic species has not been considered. In this study the hypothesis that DBM may be a complex of distinct genetic lineages or cryptic species was tested by comparing the common barcode sequence marker mtDNA COI of specimens from several populations originating from the Netherlands and Poland. The population growth rate of DBM on seven agriculturally important plant species and on various parts of the garlic plant was also experimentally assessed in the laboratory. The results did not support the first hypothesis, and indicated that DBM populations originating from Poland and the Netherlands shared essentially the same genome. In addition, they indicated that DBM reached the highest population growth rate on leek and also displayed high growth rates on garlic, chive and red onion, whereas white onion and wheat were not colonized by the mites. Answering the question of whether DBM is a single polyphagous species rather than a complex of cryptic lineages is of particular importance since the misidentification of pests may lead to ineffective control strategies. Moreover, improved knowledge of DBM host range is essential for assessing risk to crops.
Aratchige, Nayanie S.; Lesna, Izabela
Being minute in size, eriophyoid mites can reach places that are small enough to be inaccessible to their predators. The coconut mite, Aceria guerreronis, is a typical example; it finds partial refuge under the perianth of the coconut fruit. However, some predators can move under the perianth of the coconut fruits and attack the coconut mite. In Sri Lanka, the phytoseiid mite Neoseiulus baraki, is the most common predatory mite found in association with the coconut mite. The cross-diameter of this predatory mite is c. 3 times larger than that of the coconut mite. Nevertheless, taking this predator’s flat body and elongated idiosoma into account, it is—relative to many other phytoseiid mites—better able to reach the narrow space under the perianth of infested coconut fruits. On uninfested coconut fruits, however, they are hardly ever observed under the perianth. Prompted by earlier work on the accessibility of tulip bulbs to another eriophyoid mite and its predators, we hypothesized that the structure of the coconut fruit perianth is changed in response to damage by eriophyoid mites and as a result predatory mites are better able to enter under the perianth of infested coconut fruits. This was tested in an experiment where we measured the gap between the rim of the perianth and the coconut fruit surface in three cultivars (‘Sri Lanka Tall’, ‘Sri Lanka Dwarf Green’ and ‘Sri Lanka Dwarf Green × Sri Lanka Tall’ hybrid) that are cultivated extensively in Sri Lanka. It was found that the perianth-fruit gap in uninfested coconut fruits was significantly different between cultivars: the cultivar ‘Sri Lanka Dwarf Green’ with its smaller and more elongated coconut fruits had a larger perianth-fruit gap. In the uninfested coconut fruits this gap was large enough for the coconut mite to creep under the perianth, yet too small for its predator N. baraki. However, when the coconut fruits were infested by coconut mites, the perianth-rim-fruit gap was not
Lotfollahi, Parisa; Irani-Nejad, Karim Haddad; De Lillo, Enrico
This paper describes two new species of Eriophyoidea associated with trees belonging to the order Rosales in the south-western portion of East Azerbaijan province, Iran, collected during a survey in 2011: Aceria lobolinguae n. sp. on Elaeagnus angustifolia L. (Elaeagnaceae) and Rhinophytoptus nemalobos n. sp. on Prunus domestica L. (Rosaceae). Additionally, Phyllocoptes abaenus Keifer on Prunus armeniaca L. (Rosaceae), Aculus fockeui (Nalepa & Trouessart) on Prunus amygdalus Stokes and Malus domestica Borkh. (Rosaceae), and Aceria mori (Keifer) on Morus alba L. (Moraceae) were collected and are new records for the mite fauna of Iran. New locality records and host plant data are provided for Eriophyes similis (Nalepa), Eriophyes pyri (Pagenstecher) and Calepitrimerus baileyi (Keifer) which are eriophyoid species previously known from Iran.
Stilwell, Abby R.
The wheat curl mite (WCM), Aceria tosichella Keifer, transmits three viruses to winter wheat: wheat streak mosaic virus, High Plains virus, and Triticum mosaic virus. This virus complex causes yellowing of the foliage and stunting of plants. WCMs disperse by wind, and an increased understanding of mite movement and subsequent virus spread is necessary in determining the risk of serious virus infections in winter wheat. These risk parameters will help growers make better decisions regarding WCM management. The objectives of this study were to evaluate the capabilities of remote sensing to identify virus infected plants and to establish the potential of using remote sensing to track virus spread and consequently, mite movement. Although the WCM is small and very hard to track, the viruses it vectors produce symptoms that can be detected with remote sensing. Field plots of simulated volunteer wheat were established between 2006 and 2009, infested with WCMs, and spread mites and virus into adjacent winter wheat. The virus gradients created by WCM movement allowed for the measurement of mite movement potential with both proximal and aerial remote sensing instruments. The ability to detect WCM-vectored viruses with remote sensing was investigated by comparing vegetation indices calculated from proximal remote sensing data to ground truth data obtained in the field. Of the ten vegetation indices tested, the red edge position (REP) index had the best relationship with ground truth data. The spatial spread of virus from WCM source plots was modeled with cokriging. Virus symptoms predicted by cokriging occurred in an oval pattern displaced to the southeast. Data from the spatial spread in small plots of this study were used to estimate the potential sphere of influence for volunteer wheat fields. The impact of thrips on WCM populations was investigated by a series of greenhouse, field, and observational studies. WCM populations in winter wheat increased more slowly when
Investigations have been conducted in Europe in the last decade in order to find potential agents for biological control of invasive teasels in North America. During surveys conducted in Serbia in May 2007, the new eriophyid mite species Aculops dipsaci n. sp. (Acari: Prostigmata: Eriophyidae) was ...
Stewart, Lucy R
Wheat mosaic virus (WMoV), transmitted by eriophyid wheat curl mites (Aceria tosichella) is the causal agent of High Plains disease in wheat and maize. WMoV and other members of the genus Emaravirus evaded thorough molecular characterization for many years due to the experimental challenges of mite transmission and manipulating multisegmented negative sense RNA genomes. Recently, the complete genome sequence of a Nebraska isolate of WMoV revealed eight segments, plus a variant sequence of the nucleocapsid protein-encoding segment. Here, near-complete and partial consensus sequences of five more WMoV isolates are reported and compared to the Nebraska isolate: an Ohio maize isolate (GG1), a Kansas barley isolate (KS7), and three Ohio wheat isolates (H1, K1, W1). Results show two distinct groups of WMoV isolates: Ohio wheat isolate RNA segments had 84% or lower nucleotide sequence identity to the NE isolate, whereas GG1 and KS7 had 98% or higher nucleotide sequence identity to the NE isolate. Knowledge of the sequence variability of WMoV isolates is a step toward understanding virus biology, and potentially explaining observed biological variation.
Shalini, K V; Manjunatha, S; Lebrun, P; Berger, A; Baudouin, L; Pirany, N; Ranganath, R M; Prasad, D Theertha
Coconut mite (Aceria guerreronis 'Keifer') has become a major threat to Indian coconut (Coçcos nucifera L.) cultivators and the processing industry. Chemical and biological control measures have proved to be costly, ineffective, and ecologically undesirable. Planting mite-resistant coconut cultivars is the most effective method of preventing yield loss and should form a major component of any integrated pest management stratagem. Coconut genotypes, and mite-resistant and -susceptible accessions were collected from different parts of South India. Thirty-two simple sequence repeat (SSR) and 7 RAPD primers were used for molecular analyses. In single-marker analysis, 9 SSR and 4 RAPD markers associated with mite resistance were identified. In stepwise multiple regression analysis of SSRs, a combination of 6 markers showed 100% association with mite infestation. Stepwise multiple regression analysis for RAPD data revealed that a combination of 3 markers accounted for 83.86% of mite resistance in the selected materials. Combined stepwise multiple regression analysis of RAPD and SSR data showed that a combination of 5 markers explained 100% of the association with mite resistance in coconut. Markers associated with mite resistance are important in coconut breeding programs and will facilitate the selection of mite-resistant plants at an early stage as well as mother plants for breeding programs.
Rezende, Daniela; Melo, José W S; Oliveira, José E M; Gondim, Manoel G C
Reducing the losses caused by Aceria guerreronis Keifer has been an arduous task for farmers. However, there are no detailed studies on losses that simultaneously analyse correlated parameters, and very few studies that address the economic viability of chemical control, the main strategy for managing this pest. In this study the objectives were (1) to estimate the crop loss due to coconut mite and (2) to perform a financial analysis of acaricide application to control the pest. For this, the following parameters were evaluated: number and weight of fruits, liquid albumen volume, and market destination of plants with and without monthly abamectin spraying (three harvests). The costs involved in the chemical control of A. guerreronis were also quantified. Higher A. guerreronis incidence on plants resulted in a 60 % decrease in the mean number of fruits harvested per bunch and a 28 % decrease in liquid albumen volume. Mean fruit weight remained unaffected. The market destination of the harvested fruit was also affected by higher A. guerreronis incidence. Untreated plants, with higher A. guerreronis infestation intensity, produced a lower proportion of fruit intended for fresh market and higher proportions of non-marketable fruit and fruit intended for industrial processing. Despite the costs involved in controlling A. guerreronis, the difference between the profit from the treated site and the untreated site was 18,123.50 Brazilian Real; this value represents 69.1 % higher profit at the treated site.
Lima, Debora B; Melo, José Wagner S; Guedes, Nelsa Maria P; Gontijo, Lessando M; Guedes, Raul Narciso C; Gondim, Manoel Guedes C
Synthetic pesticide use has been the dominant form of pest control since the 1940s. However, biopesticides are emerging as sustainable pest control alternatives, with prevailing use in organic agricultural production systems. Foremost among botanical biopesticides is the limonoid azadirachtin, whose perceived environmental safety has come under debate and scrutiny in recent years. Coconut production, particularly organic coconut production, is one of the agricultural systems in which azadirachtin is used as a primary method of pest control for the management of the invasive coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae). The management of this mite species also greatly benefits from predation by Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae). Here, we assessed the potential behavioral impacts of azadirachtin on the coconut mite predator, N. baraki. We explored the effects of this biopesticide on overall predator activity, female searching time, and mating behavior and fecundity. Azadirachtin impairs the overall activity of the predator, reducing it to nearly half; however, female searching was not affected. In contrast, mating behavior was compromised by azadirachtin exposure particularly when male predators were exposed to the biopesticide. Consequently, predator fecundity was also compromised by azadirachtin, furthering doubts about its environmental safety and selectivity towards biological control agents.
Lima, Debora B.; Melo, José Wagner S.; Guedes, Nelsa Maria P.; Gontijo, Lessando M.; Guedes, Raul Narciso C.; Gondim, Manoel Guedes C.
Synthetic pesticide use has been the dominant form of pest control since the 1940s. However, biopesticides are emerging as sustainable pest control alternatives, with prevailing use in organic agricultural production systems. Foremost among botanical biopesticides is the limonoid azadirachtin, whose perceived environmental safety has come under debate and scrutiny in recent years. Coconut production, particularly organic coconut production, is one of the agricultural systems in which azadirachtin is used as a primary method of pest control for the management of the invasive coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae). The management of this mite species also greatly benefits from predation by Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae). Here, we assessed the potential behavioral impacts of azadirachtin on the coconut mite predator, N. baraki. We explored the effects of this biopesticide on overall predator activity, female searching time, and mating behavior and fecundity. Azadirachtin impairs the overall activity of the predator, reducing it to nearly half; however, female searching was not affected. In contrast, mating behavior was compromised by azadirachtin exposure particularly when male predators were exposed to the biopesticide. Consequently, predator fecundity was also compromised by azadirachtin, furthering doubts about its environmental safety and selectivity towards biological control agents. PMID:25679393
Lima, Debora B; Melo, José W S; Guedes, Raul N C; Siqueira, Herbert A A; Pallini, Angelo; Gondim, Manoel G C
The coconut mite, Aceria guerreronis Keifer, is a major pest of coconut palm in the world. The control of this pest species is done through acaricide applications at short time intervals. However, the predators of this pest may also be affected by acaricides. Among the predators of A. guerreronis, Neoseiulus baraki (Athias-Henriot) has potential for biological control. The objective of this study was to assess the effect of acaricides on the survival and behavior of N. baraki. The survivorship of N. baraki was recorded in surface-impregnated arenas. Choice and no-choice behavioral bioassays were carried out using a video tracking system to assess the walking behavior of the predator under acaricide exposure. Although all acaricides negatively affected the survival of N. baraki, chlorfenapyr and azadirachtin caused lower effect than the other acaricides. No significant differences in walking behavior were observed under exposure to fenpyroximate, chlorfenapyr and chlorpyrifos on fully-contaminated arenas. Azadirachtin and chlorpyrifos caused repellence. Irritability was observed for all acaricides, except for abamectin. Chlorfenapyr was the most suitable product for managing the coconut mite because of its low effect on survival and behavior of N. baraki.
Chetverikov, Philipp E; Craemer, Charnie; Vishnyakov, Andrey E; Sukhareva, Sogdiana I
A new mackielline mite, Mackiella reclinata n. sp., from a South African indigenous palm-tree, Phoenix reclinata, is described in detail using different microscopy techniques. A CSLM study of M. reclinata n. sp. internal genitalia shows that mites of this genus possess teardrop shaped spermathecae, sausage-like spermathecal tubes directed anteriad and a subtrapezoidal anterior genital apodeme with a peculiar apical plate, orthogonal to the anterior-posterior body axis. Pairwise angles between the spermatheca, spermathecal tube and the longitudinal bridge of M. reclinata n. sp. females were measured. The angle between the spermathecal tube and longitudinal bridge is a quite stable morphometric character and thus is considered to be appropriate for comparison of different eriophyoid taxa. LTSEM and CLSM study shows that M. reclinata n. sp. possesses a unique, broadened frontal lobe of the prodorsal shield comprised of apical and basal parts entirely covering the dorsal palpcoxae. The incompletely described mite species Mackiella borasis Mohanasundaram, 1981 does not conform to the diagnosis of Mackiella and herein is transferred to the subfamily Phytoptinae incertae sedis.
Melo, J W S; Lima, D B; Sabelis, M W; Pallini, A; Gondim, M G C
For more than three decades the coconut mite Aceria guerreronis Keifer is one of the most important pests of coconut palms and has recently spread to many coconut production areas worldwide. Colonization of coconut palms is thought to arise from mites dispersing aerially after take-off from other plants within the same plantation or other plantations. The underlying dispersal behaviour of the mite at take-off, in the airborne state and after landing is largely unknown and this is essential to understand how they spread from tree to tree. In this article we studied whether take-off to aerial dispersal of coconut mites is preceded by characteristic behaviour, whether there is a correlation between the body position preceding aerial dispersal and the direction of the wind, and whether the substrate (outer surface of coconut bracts or epidermis) and the wind speed matter to the decision to take-off. We found that take-off can sometimes be preceded by a raised body stance, but more frequently take-off occurs while the mite is walking or resting on its substrate. Coconut mites that become airborne assumed a body stance that had no relation to the wind direction. Take-off was suppressed on a substrate providing food to coconut mites, but occurred significantly more frequently on the outer surface of coconut bracts than on the surface of the fruit. For both substrates, take-off frequency increased with wind speed. We conclude that coconut mites have at least some degree of control over take-off for aerial dispersal and that there is as yet no reason to infer that a raised body stance is necessary to become airborne.
Melo, J W S; Lima, D B; Sabelis, M W; Pallini, A; Gondim, M G C
Ambulatory movement of plant-feeding mites sets limits to the distances they can cover to reach a new food source. In absence of food-related cues these limits are determined by survival, walking activity, walking path tortuosity and walking speed, whereas in presence of food the limits are also determined by the ability to orient and direct the path towards the food source location. For eriophyoid mites such limits are even more severe because they are among the smallest mites on earth, because they have only two pairs of legs and because they are very sensitive to desiccation. In this article we test how coconut mites (Aceria guerreronis Keifer) are constrained in their effective displacement by their ability to survive in absence of food (meristematic tissue under the coconut perianth) and by their ability to walk and orient in absence or presence of food-related cues. We found that the mean survival time decreased with increasing temperature and decreasing humidity. Under climatic conditions representative for the Tropics (27 °C and 75 % relative humidity) coconut mites survived on average for 11 h and covered 0.4 m, representing the effective linear displacement away from the origin. Within a period of 5 h, coconut mites collected from old fruits outside the perianth moved further away from the origin than mites collected under the perianth of young fruits. However, in the presence of food-related cues coconut mites traveled over 30 % larger distances than in absence of these cues. These results show that ambulatory movement of eriophyoid mites may well bring them to other coconuts within the same bunch and perhaps also to other bunches on the same coconut palm, but it is unlikely to help them move from palm to palm, given that palms usually do not touch each other.
Lotfollahi, Parisa; Irani-Nejad, Karim Haddad; Khanjani, Mohamad; Moghadam, Mohamad; De Lillo, Enrico
Five species of eriophyoid mites were identified during surveys of mite fauna associated with plant species of the family Compositae from Southwest of East Azerbaijan province during 2010 and 2011. Two of them, Aceria virgatae n. sp. from Centaurea virgata Lam. and Aceria xeranthenzis n. sp. from Xeranthemumn squarrosum Boiss., were found to be new to science. No damage symptoms were observed on their host plants. Aceria xeranthemis n. sp. is the first eriophyoid collected from the plant genus Xeranthenun. Aculops centaureae (Farkas, 1960) from Centaurea albonitens Turrill and Aceria cichorii Petanović et al. 2000 from Cichorium intybus L. are new records for Iranian mite fauna. The deutogyne female of Aceria anthocoptes (Nalepa) was recorded for the first time in Iran, too. A key to the species collected on Compositae in Iran is given.
David R. Coyle
Aculops lobuliferus (Keifer) is a little known pest of plantation Populus spp., which is capable of causing substantial damage. This is the First documented occurrence of A. lobuliferus in South Carolina. Previous anecdotal data indicated clonal variation in Populus susceptibility to A...
Only three eriophyoid mite species of the genus Leipothrix Keifer are known to occur on dipsacaceous plants including hosts in the genera Knautia (L.) Succisa Haller, and Dipsacus L.. These three species are similar, but differ in few key characters. Description of eriophyoids includes over 250 char...
Bain, Christina; Hasio, Cindy
Keifer-Boyd and Kraft's (2003) article "Inclusion Policy in Practice" inspired the creation of a new art education course as well as this article. In response to their claim that preservice training should provide greater exposure to experiences with students with special needs, during the summer of 2007 a group of University of North Texas (UNT)…
Kiedrowicz, Agnieszka; Denizhan, Evsel; Bromberek, Klaudia; Szydło, Wiktoria; Skoracka, Anna
Five new eriophyoid mite species (Eriophyidae) from Turkey are described and illustrated in this paper: Aceria vanensis n. sp., Aceria onosmae n. sp., Aculus lydii n. sp., Aculus gebeliae n. sp. and Aculus spectabilis n. sp.. The descriptions are based on the morphology of females collected from weedy plants, respectively: Amaranthus retroflexus L. (Amaranthaceae), Onosma isauricum Boiss. et Heldr. (Boraginaceae), Hypericum lydium Boiss. (Hypericaceae), Lotus gebelia Vent. (Fabaceae) and Stachys spectabilis Choisy ex DC. (Lamiaceae). The new species were found to be vagrant on their host plants with no visible damage symptoms observed.
J. L. Littlefield; G. Markin; J. Kashefi; A. de Meij; J. Runyon
Rush skeletonweed (Chondrilla juncea L.) is a major noxious weed in Idaho and other areas of the Pacific Northwest. A biological control program was implemented during the late 1970s in an attempt to manage infestations of rush skeletonweed and to limit its spread into new areas. Three agents, Cystiphora schmidti (RÃ¼bsaamen) (a gall midge), Aceria chondrillae (...
J. Andreas; T. Wax; E. Coombs; J. Gaskin; G. Markin; S. Sing
The gall mite, Aceria genistae (Nal.) Castagnoli s.l., an accidentally introduced natural enemy of Scotch broom (Cytisus scoparius (L.) Link), was first discovered in the Portland OR and Tacoma WA region in 2005. It has since been reported from southern British Columbia to southern Oregon. Observationally, the mite appears to reduce Scotch broom seed production and at...
Aceria anthocoptes is an eriophyid mite that is known to feed on Canada thistle (Cirsium arvense). While this mite species has been considered to be host specific, a detailed evaluation of its host range has yet to be determined. To assess the risks associated with using this mite as a biological ...
We submitted a petition to the APHIS Technical Advisory Group (TAG) in December 2004 requesting permission to release the blister mite (Aceria salsolae) to control Russian thistle (Salsola tragus) and its close relatives. Host specificity experiments conducted in the USDA quarantine laboratory in ...
A new species of eriophyoid mite, Aculus castriferrei n. sp., associated with Agrimonia eupatoria (Rosaceae) is described and illustrated from Hungary. Morphological differences distinguishing this vagrant species from other rosaceous inhabiting congeners are discussed. Aceria malherbae Nuzzaci is a new record for the eriophyoid fauna of Hungary after it was found causing severe damage symptoms to Convolvulus arvensis L. (Convolvulaceae).
Bouneb, Mabrouk; de Lillo, Enrico; Roversi, Pio Federico; Simoni, Sauro
Trisetacus juniperinus (Nalepa) sensu Keifer (Acari: Eriophyoidea: Phytoptidae) causes irregular development of buds, shoot deformations and stunted growth of trees, resulting in a serious threat to nurseries and young stands of Cupressus sempervirens L. (Mediterranean cypress). Recently, some cypress clones selected for their resistance to the fungal canker agent Seiridium cardinale (Wag.) have shown high susceptibility to the mite. Considering its tiny body, its hidden lifestyle inside the buds and the probable occurrence of other species (the vagrant Epitrimerus cupressi (Keifer) is common on the Mediterranean cypress in Italy), detection and monitoring of T. juniperinus require taxonomic expertise and are often time-consuming and challenging before serious damage is discernible. In the present study, a rapid, cost-effective PCR-based method was developed and validated to detect T. juniperinus on cypresses. The cytochrome c oxidase subunit I gene was amplified with degenerate and specific primers, but the latter were the only ones able to discriminate between T. juniperinus and E. cupressi. PCR products distinguished the two species both in a pool of individuals in a mixed population of both species and in single individuals, indicating the sensitivity of the detection method. PCR-RFLP (restriction fragment length polymorphism) by means of XmnI and XbaI endonucleases separated the two species. Furthermore, a washing-sieving protocol was used to make mite collection from the tree sample faster and simpler; this procedure did not interfere with the molecular detection of the species. The possibility of the routine use of this assay to monitor quarantine eriophyoids infesting plant material is discussed.
Liu, Sai; Li, Jianling; Guo, Kun; Qiao, Haili; Xu, Rong; Chen, Jianmin; Xu, Changqing; Chen, Jun
Migration by attachment to insects is common among mites that live in temporary habitats. However, because plants provide relatively stable habitats, phytophagous mites are generally not dependent on other animals for dispersal, so whether these mites can consistently be phoretic on insects through a particular life stage remains unclear and controversial. Here, we describe an obligate phoresy of a wholly phytophagous mite, Aceria pallida, in which the mites accompanied the psyllid Bactericera gobica to its winter hibernation sites, thus successfully escaping unfavourable winter conditions, and returned to reach the buds of their host plant early the following spring. This finding provides evidence of a new overwintering strategy that has contributed to the evolutionary success of these tiny phytophagous mites. PMID:27150196
Momen, Faten Mamdouh
The influence of various life diets on the biology and demographic parameters of the predatory mite, Agistemus olivi Romeih, was studied under laboratory conditions. A. olivi successfully developed and reproduced on all of the tested eriophyid mites. Feeding on Aceria mangiferae Sayed enhanced the development of A. olivi, resulted in the shortest mean generation time and was the most commensurate food for the ovipostion of the predator, as exhibited by the highest fecundity and net reproductive rate. Preying on Aculops lycopersici (Massee) gave the lowest fecundity and net reproductive rate; therefore, this prey was the least suitable for the oviposition of A. olivi. Preying on Aculus fockeui (Nalepa et Trouessart) and A. mangiferae produced higher intrinsic rates of increase and finite rates of increase for the predator in comparison to A. lycopersici, which showed the lowest value. These differences in response to various eriophyid pests should be considered for the production of healthy cultures of A. olivi.
Chetverikov, Philipp E; Desnitskiy, Alexey G; Navia, Denise
Due to the higher resolution, confocal microscopy (CLSM) can be applied to refine the origin of tiny structures of the autofluorescent exoskeletons of microarthropods (mites in particular) which are hard to visualize using traditional differential interference contract light microscopy (DIC LM) and phase contrast light microscopy (PC LM). Three-dimensional (3D) reconstructions of the prodorsal shield topography of eriophyoid mites using Neoprothrix hibiscus Reis and Navia as a model, suggest that the structures originally treated as paired setae vi are two internal rod-like apodemes. Based on this, the genus Neoprothrix is excluded from the subfamily Prothricinae Amrine and transferred to the subfamily Sierraphytoptinae Keifer. Observations on partially cleared specimens of N. hibiscus showed that remnants of the central nervous system, paired glands and developing oocytes can be visualized using DIC LM and CLSM methods. New high quality microscope images are provided of recently described "flower-shaped" structures and two main components of yolk inclusions of the mature eggs inside the oviduct.
Navia, Denise; Ferreira, Cecília B S; Reis, Aleuny C; Gondim, Manoel G C
Cryptic diversity has been confirmed for several phytophagous mites in the Eriophyoidea superfamily previously considered as presenting low host specificity. Among generalist eriophyoids is the phytoptid Retracrus johnstoni Keifer, which has been reported in 19 palm species belonging to 11 genera, causing severe damage on some of them. Surprisingly this species was recently reported on another monocot family, Heliconiaceae, infesting Heliconia plants in Costa Rica and Brazil, being the only in the tribe Mackiellini to not be associated with palm trees. This study aimed to investigate the occurrence of cryptic species in R. johnstoni and to clarify the taxonomic status of populations associated with heliconias in the Americas. With this purpose traditional and geometric morphometric analyses were conducted as well as a detailed morphological study. Measurable trait data were analysed via univariate and multivariate analyses. Shapes of specimens from different populations were compared via geometric morphometric landmark methods. Morphometric analysis supported occurrence of at least two cryptic species previously identified as R. johsntoni and suggested occurrence of cryptic species among populations associated with different palm trees. Taxonomic descriptions of two new taxa associated with heliconias, namely Retracrus costaricensis n. sp. Ferreira and Navia and Retracrus heliconiae n. sp. Ferreira and Navia are presented. Morphometric traits that can be useful in the taxonomic identification are noted and their value is discussed. Results of the traditional morphometry and geometric methods were compared and the advantages of their joint use for Eriophyoidea systematics are discussed.
Witters, J; De Bondt, G; Desamblanx, J; Casteels, H
During the period 2004-2006, 1691 samples of different origin were examined at the Diagnostic Centre for Plants. We received 1046 samples of imported plant material for detection and identification of quarantine organisms. More than 200 samples were checked on mites and insects to get a phytosanitary certificate for export and 391 samples were investigated for diagnostic reason. The Berlese-funnel and dissecting microscopy technique were used to separate mites from the samples. For identification, the mites were slide mounted in Berlese-Hoyer's medium and examined by using phase-contrast microscopy. In 3% of the samples examined on the presence of quarantine organisms, phytophagous mites belonging to the superfamily Tetranychoidea were found, but none with the quarantine status in accordance with the EPPO A1/A2 list. Besides Tetranychus urticae detected on different crops, the cassava green mite Mononychellus progresivus was found on cassava (import Cameroon) in 2006. Tenuipalpus elegans (Tenuipalpidae) was found on cut foliage (import South Africa) in 2004. In 19.9% of the investigated samples for diagnostic reason mites were found. In 47.7% of the infested samples mites were definitely the reason for the damage; in 15.9% mites were secondary and in 36.4% the occurrence of mites was not relevant for the injury. An overview of the determined mites will be given. During this 3 years diagnostic research a few new pest mites belonging to families Tetranychidae and Eriophyidae can be reported. In 2006 Panonychus citri was found on Prunus laurocerasus and later on Eleaegnus sp. and Skimmia sp.. Aceria silvicola was determined on Rubus idaeus in 2006 and Aculus ulae and Aceria carpini on Carpinus betulus in 2005. Besides new pest mites, never seen problems with the broad mite Polyphagotarsonemus latus (Fam. Tarsonemidae) occurred in tree-nurseries in 2005 and 2006. Also 20 samples coming from private persons were investigated. The main problems indoor were caused by
Identification of Coupling and Repulsion Phase DNA Marker Associated With an Allele of a Gene Conferring Host Plant Resistance to Pigeonpea sterility mosaic virus (PPSMV) in Pigeonpea (Cajanus cajan L. Millsp.)
Daspute, Abhijit; Fakrudin, B.
Pigeonpea Sterility Mosaic Disease (PSMD) is an important foliar disease caused by Pigeonpea sterility mosaic virus (PPSMV) which is transmitted by eriophyid mites (Aceria cajani Channabasavanna). In present study, a F2 mapping population comprising 325 individuals was developed by crossing PSMD susceptible genotype (Gullyal white) and PSMD resistant genotype (BSMR 736). We identified a set of 32 out of 300 short decamer random DNA markers that showed polymorphism between Gullyal white and BSMR 736 parents. Among them, eleven DNA markers showed polymorphism including coupling and repulsion phase type of polymorphism across the parents. Bulked Segregant Analysis (BSA), revealed that the DNA marker, IABTPPN7, produced a single coupling phase marker (IABTPPN7414) and a repulsion phase marker (IABTPPN7983) co-segregating with PSMD reaction. Screening of 325 F2 population using IABTPPN7 revealed that the repulsion phase marker, IABTPPN7983, was co-segregating with the PSMD responsive SV1 at a distance of 23.9 cM for Bidar PPSMV isolate. On the other hand, the coupling phase marker IABTPPN7414 did not show any linkage with PSMD resistance. Additionally, single marker analysis both IABTPPN7983 (P<0.0001) and IABTPPN 7414 (P<0.0001) recorded a significant association with the PSMD resistance and explained a phenotypic variance of 31 and 36% respectively in F2 population. The repulsion phase marker, IABTPPN7983, could be of use in Marker-Assisted Selection (MAS) in the PPSMV resistance breeding programmes of pigeonpea. PMID:25774108
Aratchige, N S; Lesna, I; Sabelis, M W
Although odour-mediated interactions among plants, spider mites and predatory mites have been extensively studied above-ground, belowground studies are in their infancy. In this paper, we investigate whether feeding by rust mites (Aceria tulipae) cause tulip bulbs to produce odours that attract predatory mites (Neoseiulus cucumeris). Since our aim was to demonstrate such odours and not their relevance under soil conditions, the experiments were carried out using a classic Y-tube olfactometer in which the predators moved on a Y-shaped wire in open air. We found that food-deprived female predators can discriminate between odours from infested bulbs and odours from uninfested bulbs or artificially wounded bulbs. No significant difference in attractiveness to predators was found between clean bulbs and bulbs either wounded 30 min or 3 h before the experiment. These results indicate that it may not be simply the wounding of the bulbs, but rather the feeding by rust mites, which causes the bulb to release odours that attract N. cucumeris. Since bulbs are belowground plant structures, the olfactometer results demonstrate the potential for odour-mediated interactions in the soil. However, their importance in the actual soil medium remains to be demonstrated.
Zhao, Zi-Hua; Zhang, Rong; He, Da-Han; Wang, Fang; Zhang, Ting-Ting; Zhang, Zong-Shan
In the risk assessment of pests, both the community structure and the environmental factors should be considered at the same time, because of their mutual effects on the outbreak of disaster pests. This paper established a comprehensive assessment system, including 2 sub-systems, 5 respects, and 14 indices. In the meanwhile, risk assessment indices and experience formula were used to analyze the risk degree of pests in Lycium barbarum fields under different managements. It was found that using risk assessment indices and experience formula could obtain similar results. In abandoned field, Aceria palida, Aphis sp., and Paratrioza sinica were the frequent disaster pests, Lema decempunctata, Neoceratitis asiatica, Jaapiella sp., and Phthorimaea sp. were the incidental disaster pests, and Psylliodes obscurofaciata and Phthorimaea sp. were general pests. In organic field, the frequent disaster pests were the same species as those in abandoned field, while P. indicus, Jaapiella sp. and Phthorimaea sp. were the incidental disaster pests. In chemical control field, A. palida, Aphis sp., P. sinica, and P. indicus were the frequent disaster pests, while Jaapiella sp. and Phthorimaea sp. were the incidental disaster pests. Optimal 5 separations most fitted the division of pest sub-communities in L. barbarum fields, which were infancy period (from March 28 to April 15), outbreak I period (from April 15 to July 18), dormancy period (from July 18 to September 8), outbreak II period (from September 8 to October 15), and recession period (after October 15). The matrix of correlation coefficient showed that the dynamics of pests in L. barbarum fields under different managements were significantly correlated with each other, suggesting that the dynamics of pest populations was similar in different L. barbarum fields, which had two population establishment stages and one exponential growth stage in every year. The optimal controlling stages were from late infancy period to early and
Mikunthan, G; Manjunatha, M
Microbial control is receiving more attention, since these alternative tactics, compared to chemical control methods, are energy saving, non polluting, ecologically sound and sustainable. A mycopathogen, Fusarium semitectum Berk. and Rav. (ARSEF 7233) was isolated from diseased cadavers of aphid (Aphis gossypii) and cultured in Saboraud Maltose Agar supplemented with Yeast extract medium (SMAY). Being isolated first time from the chilli ecosystem its potential was evaluated. Experiments were conducted to understand its pathogenicity against crop pests as well as to ensure its safety to non target organisms such as silk worm (Bombyx mor), honey bee (Apis indica) and earthworm (Eisenia foetida). A paper-thrips-paper sandwich method for thrips and detached-leaf bioassay method for mites were used. Test insects and mites either reared in laboratory or obtained from the field were topically applied with spore suspension of F. semitectum (1x10(9) spores/ml). Mortality was recorded and dead animals were surface sterilized with 0.5% NaOCl and placed in SMAY medium to confirm pathogenicity. Mulberry leaves sprayed with the fungal suspension were fed to larvae of B. mori and reared. Newly emerged A. indica were topically applied with fungus. The fungus grown in cow dung for two weeks was used to assess the composting ability of E. foetida. F. semitectum produced mycosis and caused mortality to sucking pests such as chilli thrips (Scirtothrips dorsalis), broad mite (Polyphagotarsonemus latus), sugarcane wooly aphid (Ceratavacuna lanigera), spiraling whitefly (Aleyrodicus disperses), whitefly (Bemisia tabaci, A. gossypii and coconut mite (Aceria guerroronis). The fungus did not cause mortality on larvae of lepidopteran insect pests and ladybird beetle (Menochilus sexmaculatus), predatory mite (Amblysius ovalis) and larval parasitoid (Goniozus nephantidis). F. semitectum failed to infect the larvae of B. mori and newly emerged A. indica and its brood. The mycopathogen had no
Lesna, Izabela; da Silva, Fernando R; Sato, Yukie; Sabelis, Maurice W; Lommen, Suzanne T E
The dry bulb mite, Aceria tulipae, is the most important pest of stored tulip bulbs in The Netherlands. This tiny, eriophyoid mite hides in the narrow space between scales in the interior of the bulb. To achieve biological control of this hidden pest, candidate predators small enough to move in between the bulb scales are required. Earlier experiments have shown this potential for the phytoseiid mite, Neoseiulus cucumeris, but only after the bulbs were exposed to ethylene, a plant hormone that causes a slight increase in the distance between tulip bulb scales, just sufficient to allow this predator to reach the interior part of the bulb. Applying ethylene, however, is not an option in practice because it causes malformation of tulip flowers. In fact, to prevent this cosmetic damage, bulb growers ventilate rooms where tulip bulbs are stored, thereby removing ethylene produced by the bulbs (e.g. in response to mite or fungus infestation). Recently, studies on the role of predatory mites in controlling another eriophyoid mite on coconuts led to the discovery of an exceptionally small phytoseiid mite, Neoseiulus paspalivorus. This predator is able to move under the perianth of coconuts where coconut mites feed on meristematic tissue of the fruit. This discovery prompted us to test N. paspalivorus for its ability to control A. tulipae on tulip bulbs under storage conditions (ventilated rooms with bulbs in open boxes; 23 °C; storage period June-October). Using destructive sampling we monitored predator and prey populations in two series of replicated experiments, one at a high initial level of dry bulb mite infestation, late in the storage period, and another at a low initial dry bulb mite infestation, halfway the storage period. The first and the second series involved treatment with N. paspalivorus and a control experiment, but the second series had an additional treatment in which the predator N. cucumeris was released. Taking the two series of experiments together