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J. Jaenike - One of the best experts on this subject based on the ideXlab platform.
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INFECTION SUCCESS IN NOVEL HOSTS: AN EXPERIMENTAL AND PHYLOGENETIC STUDY OF DROSOPHILA‐PARASITIC NEMATODES
Evolution; international journal of organic evolution, 2003Co-Authors: Steve J. Perlman, J. JaenikeAbstract:Surprisingly little is known about what determines a parasite's host range, which is essential in enabling us to predict the fate of novel infections. In this study, we evaluate the importance of both host and parasite phylogeny in determining the ability of parasites to infect novel host species. Using experimental lab assays, we infected 24 taxonomically diverse species of Drosophila flies (Diptera: Drosophilidae) with five different nematode species (Ty- lenchida: Allantonematidae: Howardula, Parasitylenchus), and measured parasite infection success, growth, and effects on female host fecundity (i.e., virulence). These nematodes are obligate parasites of mushroom-feeding Drosophila, particularly quinaria and testacea group species, often with severe fitness consequences on their hosts. We show that the potential host ranges of the nematodes are much larger than their actual ranges, even for parasites with only one known host species in nature. Novel hosts that are distantly related from the native host are much less likely to be infected, but among more closely related hosts, there is much variation in susceptibility. Potential host ranges differ greatly between the related parasite species. All nematode species that successfully infected novel hosts produced infective juveniles in these hosts. Most novel infections did not result in significant reductions in the fecundity of female hosts, with one exception: the host specialist Parasitylenchus nearcticus sterilized all quinaria group hosts, only one of which is a host in nature. The large potential host ranges of these parasites, in combination with the high potential for host colonization due to shared mushroom breeding sites, explain the widespread host switching observed in comparisons of nematode and Drosophila phylogenies.
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Associations between mycophagous Drosophila and their Howardula nematode parasites: a worldwide phylogenetic shuffle.
Molecular ecology, 2002Co-Authors: Steve J. Perlman, Greg S. Spicer, Dewayne Shoemaker, J. JaenikeAbstract:Little is known about what determines patterns of host association of horizontally transmitted parasites over evolutionary timescales. We examine the evolution of associations between mushroom-feeding Drosophila flies (Diptera: Drosophilidae), particularly in the quinaria and testacea species groups, and their horizontally transmitted Howardula nematode parasites (Tylenchida: Allantonematidae). Howardula species were identified by molecular characterization of nematodes collected from wild-caught flies. In addition, DNA sequence data is used to infer the phylogenetic relationships of both host Drosophila (mtDNA: COI, II, III) and their Howardula parasites (rDNA: 18S, ITS1; mtDNA: COI). Host and parasite phylogenies are not congruent, with patterns of host association resulting from frequent and sometimes rapid host colonizations. Drosophila -parasitic Howardula are not monophyletic, and host switches have occurred between Drosophila and distantly related mycophagous sphaerocerid flies. There is evidence for some phylogenetic association between parasites and hosts, with some nematode clades associated with certain host lineages. Overall, these host associations are highly dynamic, and appear to be driven by a combination of repeated opportunities for host colonization due to shared breeding sites and large potential host ranges of the nematodes.
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Howardula neocosmis sp.n. parasitizing North American Drosophila (Diptera: Drosophilidae) with a listing of the species of Howardula Cobb, 1921 (Tylenchida: Allantonematidae)
Fundamental and applied nematology, 1998Co-Authors: G. O. Poinar, J. Jaenike, Dew. D. ShoemakerAbstract:Description est donnee d'Howardula neocosmis sp. n. (Tylenchida : Allantonematidae) parasite de Drosophila acutilabella Stalker (Diptera : Drosophilidae) provenant de Floride, USA et de D. suboccidentalis Spencer provenant de Colombie Britannique, Canada. Ces deux souches representent le premier Howardula decrit sur des drosophiles nord-americaines. Des notes sur la biologie de ce parasite et une liste des especes du genre Howardula Cobb sont presentees.
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Parasitylenchus nearcticus sp. n. (Tylenchida : Allantonematidae) parasitizing Drosophila (Diptera : Drosophilidae) in North America
Fundamental and applied nematology, 1997Co-Authors: G. O. Poinar, J. Jaenike, I. DombeckAbstract:Parasitylenchus nearcticus sp. n. (Tylenchida: Allantonematidae) est decrit comme parasite de Drosophila recens (Diptera : Drosophilidae) recolte dans les Adirondacks Mountains, Etat de New York, Etats-Unis d'Amerique. Cette nouvelle espece est comparee a la seule espece connue - en Grande-Bretagne - du genre Parasitylenchus, et une cle des Allantonematidae parasites de Drosophilidae est presentee. Les femelles des deux generations parasites montrent un dimorphisme dans la forme du stylet et des glandes pharyngiennes. P. nearcticus sp. n. sterilise les femelles de D. recens, ayant ainsi un impact sur l'ecologie des populations de son hote.
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Mycophagous Drosophila and their nematode parasites
The American Naturalist, 1992Co-Authors: J. JaenikeAbstract:The nematode Howardula aoronymphium (Allantonematidae) parasitizes several mushroom-feeding species of Drosophila of the quinaria and testacea species groups in eastern North America. The principal effect of nematodes on their hosts is a reduction in female fertility: females of Drosophila putrida and Drosophila testacea are sterilized by these parasites. The prevalence of parasitism varies substantially among host species and through time, showing evidence of seasonal as well as year-to-year variation. Because the principal effect of these parasites is on host reproduction and because they are not highly aggregated among hosts, this parasite-host system may be prone to unstable population dynamics. Some field evidence suggests that H. aoronymphium may influence the outcome of competition among its host species Because these parasites and their hosts have similar population sizes, generation times, and rates of gene flow, they may interact evolutionarily in a dynamically interesting manner
George Poinar - One of the best experts on this subject based on the ideXlab platform.
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Proparasitylenchus californicus n. sp. (Tylenchida: Allantonematidae), parasitic in the intertidal rove beetle Tarphiota geniculata (Mäklin) (Coleoptera: Staphylinidae) in California, USA
Systematic Parasitology, 2015Co-Authors: George Poinar, Nicole Datlen, Magaly Espinoza, John MclaughlinAbstract:A new nematode species, Proparasitylenchus californicus n. sp., is described from the intertidal rove beetle Tarphiota geniculata (Mäklin) (Coleoptera: Staphylinidae) in California, USA. The new species differs from European representatives of the genus by possessing a cleft stylet in both sexes. The parasitic female is ovoviviparous and produces numerous juveniles that moult twice in the beetle host, then exit and moult twice to the adult stage in the environment. After mating, the free-living fertilised females enter a new host. Heavy infections sterilise the beetles. This is the first record of the genus Proparasitylenchus Wachek, 1955 in the New World and the first allantonematid parasite of a marine, intertidal beetle.
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Natural parasitism of Metaparasitylenchus hypothenemi (Tylenchida: Allantonematidae) on the coffee berry borer in Chiapas, Mexico
Biocontrol Science and Technology, 2015Co-Authors: Jeanneth Pérez, George Poinar, Alfredo Castillo, Francisco Infante, Fernando E. VegaAbstract:We assessed the parasitism of Metaparasitylenchus hypothenemi on its host, the coffee berry borer, in 20 coffee plantations of Mexico. A total of 23,568 adult borers were dissected, with 179 of the...
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SHORT COMMUNICATION Natural parasitism of Metaparasitylenchus hypothenemi (Tylenchida: Allantonematidae) on the coffee berry borer in Chiapas, Mexico
2015Co-Authors: Jeanneth Pérez, George Poinar, Alfredo Castillo, Francisco Infante, Fernando E. VegaAbstract:The parasitic nematode Metaparasitylenchus hypothenemi (Tylenchida: Allantonematidae) was first reported infecting the coffee berry borer (Hypothenemus hampei (Ferrari); Coleoptera: Curculionidae: Scolytinae) in coffee plantations of Chiapas, Mexico (Castillo, Infante, Barrera, Carta, & Vega, 2002), and was later described as a new species (Poinar, Vega, Castillo, Chavez, & Infante, 2004). This discovery was noteworthy because it increased the limited number of natural enemies attacking the coffee berry borer, the main insect pest of coffee worldwide (Vega, Infante, Castillo, & Jaramillo, 2009; Vega, Infante, & Johnson, 2015), and revealed the presence of endemic populations of a biological control agent in an area where the insect had been introduced. Even though several papers have reported on commercially available entomopathogenic nematodes (Steinernema or Heterorhabditis) infecting the coffee berry borer in the laboratory (Allard & Moore, 1989; Castillo & MarbanMendoza, 1996; Lara, Lopez-Nunez, & Bustillo, 2004; Benavides, Quintero, & Lopez, 2010; Manton, Hollingsworth, & Cabos, 2012), only one other record of a nematode attacking the insect under natural conditions exists: Panagrolaimus sp. (Rhabditida: Panagrolamidae) parasitizing adult coffee berry borers in India (Varaprasad, Balasubramanian, Diwakar, & Rao, 1994). M. hypothenemi infects larvae, pupae and adult stages of the coffee berry borer, causing partial or complete sterilisation of adult females (Poinar et al., 2004). In this study, we assessed the natural parasitism and distribution of M. hypothenemi in coffee plantation in the state of Chiapas, Mexico, in order to elucidate its role in the biological control of the coffee berry borer.
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Halophilanema prolata n. gen., n. sp. (Nematoda: Allantonematidae), a parasite of the intertidal bug, Saldula laticollis (Reuter)(Hemiptera: Saldidae) on the Oregon coast
Parasites & vectors, 2012Co-Authors: George PoinarAbstract:Background It is rare to find terrestrial nematode lineages parasitizing arthropods inhabiting the intertidal or littoral zone of the oceans. During an ecological study along the Oregon dunes, an allantonematid nematode (Tylenchomorpha: Allantonematidae) was discovered parasitizing the intertidal shore bug, Saldula laticollis (Reuter)(Hemiptera: Saldidae). This shore bug is adapted to an intertidal environment and can survive short periods of submergence during high tides. The present study describes the nematode parasite and discusses aspects of its development, ecology and evolution.
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Nematode Parasites and Associates of Ants: Past and Present
Psyche: A Journal of Entomology, 2012Co-Authors: George PoinarAbstract:Ants can serve as developmental, definitive, intermediate, or carrier hosts of a variety of nematodes. Parasitic ant nematodes include members of the families Mermithidae, Tetradonematidae, Allantonematidae, Seuratidae, Physalopteridae, Steinernematidae, and Heterorhabditidae. Those nematodes that are phoretically associated with ants, internally or externally, are represented by the Rhabditidae, Diplogastridae, and Panagrolaimidae. Fossils of mermithids, tetradonematids, allantonematids, and diplogastrids associated with ants show the evolutionary history of these relationships, some of which date back to the Eocene (40 mya).
G. O. Poinar - One of the best experts on this subject based on the ideXlab platform.
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FlIndam. app!. Nemawl., 1997,20 (2),187-190 Parasitylenchus nearcticus sp. n. (Tylenchida: Allantonematidae) parasitizing Drosophila (Diptera: Drosophilidae) in North America
2015Co-Authors: G. O. Poinar, I. DombeckAbstract:Summary- Parasitylenchus nearclicus sp. n. (Tylenchida: Allantonematidae) is described as a parasite of Drosophila recen
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Parasitylenchus bifurcatus n. sp. (Tylenchida: Allantonematidae) parasitizing Harmonia axyridis (Coleoptera: Coccinellidae)
Parasites & Vectors, 2012Co-Authors: G. O. Poinar, Tove SteenbergAbstract:Background The harlequin ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is native to central and eastern Asia and was purposely introduced into Europe to control aphids. While it proved to be a good biological control agent, its rapid spread and buildup of large populations made it a nuisance, since it overwinters in homes, emits unpleasant odors, stains fabrics, occasionally bites humans and feeds on apples, pears and grapes. Aside from the above, the ravenous appetite of H. axyridis results in their consumption of harmless native insects, including even other ladybird beetles. A study of the natural enemies of H. axyridis in Denmark revealed the presence of nematodes. The present study describes this nematode parasite and discusses aspects of its development and ecology. Methods Adult harlequin ladybird beetles were collected from March to November from four localities in Copenhagen on different plant species. In addition, groups of last-instar larvae and pupae (n = 50) were examined for the presence of nematodes. Living and recently dead nematodes were removed from adult H. axyridis in 0.5% saline solution, the nematodes were then heat killed (at 75C), fixed in 5% formalin and transferred to glycerin on slides for further examination and measurements. Results A new species of Allantonematidae (Tylenchida), Parasitylenchus bifurcatus n. sp., is described from adults of the harlequin ladybird, Harmonia axyridis in Denmark. The new species is characterized by a straight stylet lacking basal thickenings, a bursa and a forked tail tip in the vermiform (infective) females and juvenile males. The new species is compared with P. coccinellinae previously described from ladybird beetles in France. Parasitism resulted in depletion of the fat body and partial or complete atrophy of the reproductive organs of the beetles. Infections occurred throughout the year with rates of parasitism reaching up to 35%. The rate increased to 60% when field-collected ladybirds were incubated for 30 days in the laboratory. Conclusions The production of subsequent generations within the host with only the fertilized females (not the males) leaving the hosts and the absence of parasitism of the larvae and pupae is an impressive developmental modification of P. bifurcatus . It is proposed that the vermiform (infective) females pass from one adult host to another when the beetles are hibernating or in assemblage groups. Rates of parasitism show that P. bifurcatus could be a significant biological control agent of H. axyridis .
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Halophilanema prolata n. gen., n. sp. (Nematoda: Allantonematidae), a parasite of the intertidal bug, Saldula laticollis (Reuter)(Hemiptera: Saldidae) on the Oregon coast
Parasites & Vectors, 2012Co-Authors: G. O. PoinarAbstract:Background It is rare to find terrestrial nematode lineages parasitizing arthropods inhabiting the intertidal or littoral zone of the oceans. During an ecological study along the Oregon dunes, an allantonematid nematode (Tylenchomorpha: Allantonematidae) was discovered parasitizing the intertidal shore bug, Saldula laticollis (Reuter)(Hemiptera: Saldidae). This shore bug is adapted to an intertidal environment and can survive short periods of submergence during high tides. The present study describes the nematode parasite and discusses aspects of its development, ecology and evolution. Methods Adults and last instar nymphs of S. laticollis (Hemiptera: Saldidae) were collected from the high intertidal zone among clumps of Juncus L. (Juncaceae) plants at Waldport, Oregon on October 3, 2011. The bugs were dissected in 1% saline solution and the nematodes killed in 1% Ringers solution and immediately fixed in 5% formalin (at 20°C). Third stage juveniles removed from infected hosts were maintained in 1% saline solution until they matured to the adult stage, molted and mated. Results Halophilanema prolata n. gen., n. sp. (Nematoda: Allantonematidae) is described from last instar nymphs and adults of the intertidal bug, Saldula laticollis on the Oregon coast. The new genus can be distinguished from other genera in the Allantonematidae by a stylet lacking basal knobs in both sexes, an excretory pore located behind the nerve ring, ribbed spicules, a gubernaculum, the absence of a bursa and the elongate-tubular shape of the ovoviviparous parasitic females. Studies of the organogenesis of Halophilanema showed development to third stage juveniles in the uterus of parasitic females. Maturation to the free-living adults and mating occurred in the environment. The incidence of infection of S. laticollis ranged from 0% to 85% depending on the microhabitat in the intertidal zone. Conclusions Based on the habitat and morphological characters, it is proposed that Halophilanema adapted a parasitic existence fairly recently, evolutionarily speaking. It was probably a free-living intertidal or shore nematode that fed on microorganisms, especially fungi, in the intertidal habitat and became parasitic after saldids entered the environment. Halophilanema represents the first described nematode parasite of an intertidal insect.
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Howardula neocosmis sp.n. parasitizing North American Drosophila (Diptera: Drosophilidae) with a listing of the species of Howardula Cobb, 1921 (Tylenchida: Allantonematidae)
Fundamental and applied nematology, 1998Co-Authors: G. O. Poinar, J. Jaenike, Dew. D. ShoemakerAbstract:Description est donnee d'Howardula neocosmis sp. n. (Tylenchida : Allantonematidae) parasite de Drosophila acutilabella Stalker (Diptera : Drosophilidae) provenant de Floride, USA et de D. suboccidentalis Spencer provenant de Colombie Britannique, Canada. Ces deux souches representent le premier Howardula decrit sur des drosophiles nord-americaines. Des notes sur la biologie de ce parasite et une liste des especes du genre Howardula Cobb sont presentees.
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Parasitylenchus nearcticus sp. n. (Tylenchida : Allantonematidae) parasitizing Drosophila (Diptera : Drosophilidae) in North America
Fundamental and applied nematology, 1997Co-Authors: G. O. Poinar, J. Jaenike, I. DombeckAbstract:Parasitylenchus nearcticus sp. n. (Tylenchida: Allantonematidae) est decrit comme parasite de Drosophila recens (Diptera : Drosophilidae) recolte dans les Adirondacks Mountains, Etat de New York, Etats-Unis d'Amerique. Cette nouvelle espece est comparee a la seule espece connue - en Grande-Bretagne - du genre Parasitylenchus, et une cle des Allantonematidae parasites de Drosophilidae est presentee. Les femelles des deux generations parasites montrent un dimorphisme dans la forme du stylet et des glandes pharyngiennes. P. nearcticus sp. n. sterilise les femelles de D. recens, ayant ainsi un impact sur l'ecologie des populations de son hote.
Kevin M. Heinz - One of the best experts on this subject based on the ideXlab platform.
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Thrips Parasitic Nematode Thripinema nicklewoodi (Tylenchida: Allantonematidae) Reduces Feeding, Reproductive Fitness, and Tospovirus Transmission by Its Host, Frankliniella occidentalis (Thysanoptera: Thripidae)
Environmental Entomology, 2003Co-Authors: Steven P. Arthurs, Kevin M. HeinzAbstract:Abstract The parasitic nematode Thripinema nicklewoodi is a potential inoculative biological control agent of the western flower thrips, Frankliniella occidentalis. Laboratory studies were undertaken to assess the effect of T. nicklewoodi infection on: 1) host feeding, 2) host fecundity, and 3) viral competency of F. occidentalis coinfected with a tospovirus. Individual thrips infected with nematodes as larvae and maintained on leaf discs in microcentrifuge vials showed a reduced feeding throughout the adult life span. This per capita reduction in feeding by parasitized individuals contributed to a total reduction in feeding of 87% on chrysanthemum petals and 91% on bean foliage relative to uninfected thrips. Parasitism also reduced the longevity of adult thrips by 3–5 d, although the preadult developmental time was unaffected. In a separate study, thrips infected with nematodes as larvae became reproductively sterile and appeared to have a reduced vector competency for tomato spotted wilt virus (TSWV). T...
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In vivo rearing of Thripinema nicklewoodi (Tylenchida: Allantonematidae) and prospects as a biological control agent of Frankliniella occidentalis (Thysanoptera: Thripidae).
Journal of economic entomology, 2002Co-Authors: Steven P. Arthurs, Kevin M. HeinzAbstract:Methods are described for the in vivo production of the nematode Thripinema nicklewoodi (Siddiqi), an obligate parasite and potential biological control agent of western flower thrips Frankliniella occidentalis (Pergande). Nematode infection is not lethal but causes sterilization of adult female hosts. Both fertilization and horizontal transmission of T. nicklewoodi is achieved in 1.5-ml microcentrifuge tubes (infection arenas), in the presence of 100% humidity, a temporary food source and preferably a damp substrate. Following exposure to infection arenas, F. occidentalis are reared on excised bean leaves Phaseolus vulgaris (L.) in polypropylene containers for 2 wk at 25°C to allow the reproduction and development of a single generation of nematodes within infected hosts’s abdominal cavity. To identify infected hosts after this incubation period, thrips are isolated in microcentrifuge tubes and monitored for free-living nematodes being released along with frass. Infected thrips are reintroduced back into infection arenas to inoculate further thrips to maintain the culture. We documented the output of the rearing procedure using a standard method and following simple manipulation of several individual parameters of the infection technique. The standard method was the most efficient, and resulted in an increased (output/input) ratio of infected thrips of ≈2; i.e., the number of infected thrips approximately doubles each generation. Monitoring infected thrips revealed that nematodes were first released between 12–14 d postinfection and for an average of 7.9 d at 25°C; highlighting the potential to reuse infective thrips between infection arenas. The possibility of using T. nicklewoodi as an inoculative agent against F. occidentalis infesting floricultural crops is discussed.
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Biological Attributes of the Nematode, Thripinema nicklewoodi, a Potential Biological Control Agent of Western Flower Thrips
Biological Control, 2001Co-Authors: Un Taek Lim, R. G. Van Driesche, Kevin M. HeinzAbstract:Abstract Western flower thrips (WFT), Frankliniella occidentalis (Thysanoptera: Thripidae), is the most important insect pest for greenhouse flower crops, but chemical control is often difficult because of the thrips' location in flowers and buds. Thripinema nicklewoodi (Tylenchida: Allantonematidae) is an entomoparasitic nematode that attacks and sterilizes WFT, but its biology and impact on WFT are poorly understood. Methods to propagate and study T. nicklewoodi with a microscope slide arena for observation and a rolled bean leaf arena for rearing were developed. On average, 21.4 nematodes were excreted per day by a parasitized female WFT. The sex ratio of the excreted nematodes was 6.0/1.0 (female/male). After dissection of adult WFT, a maximum of 11 ovoid-shaped first-generation nematodes in a female thrips and 6 in a male thrips were found. There were more second-generation nematodes in the adult female WFT (192.6) than in the adult male WFT (93.7). When 50 healthy first instar WFT were exposed to 4 parasitized female WFT in a rolled bean leaf, a 75.3% mean parasitization rate in the adult stage of the thrips was obtained. In contrast to previous reports, male WFT can be parasitized as readily as females. Parasitism reduced the longevity of both adult female and adult male WFT, and the degree of reduction was higher in adult male WFT. T. nicklewoodi, when presented with various WFT life stages (first instar, second instar, prepupa, pupa, adult female, and adult male), achieved the highest attack rate in first and second instars and prepupa. The free-living nematodes excreted by the hosts actively migrated to a trichome on leaf disks in the observation arena and moved up this structure. Then, the nematode actively waved the anterior part of its body while attaching itself to the trichome with the posterior part of its body. After a nematode contacted the leg of a thrips, the nematode immediately moved up along the leg toward the abdomen of the host. Increased understanding of the biology of T. nicklewoodi is important to better assess its potential for biological control of WFT.
Tove Steenberg - One of the best experts on this subject based on the ideXlab platform.
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Parasitylenchus bifurcatus n. sp. (Tylenchida: Allantonematidae) parasitizing Harmonia axyridis (Coleoptera: Coccinellidae)
Parasites & Vectors, 2012Co-Authors: G. O. Poinar, Tove SteenbergAbstract:Background The harlequin ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is native to central and eastern Asia and was purposely introduced into Europe to control aphids. While it proved to be a good biological control agent, its rapid spread and buildup of large populations made it a nuisance, since it overwinters in homes, emits unpleasant odors, stains fabrics, occasionally bites humans and feeds on apples, pears and grapes. Aside from the above, the ravenous appetite of H. axyridis results in their consumption of harmless native insects, including even other ladybird beetles. A study of the natural enemies of H. axyridis in Denmark revealed the presence of nematodes. The present study describes this nematode parasite and discusses aspects of its development and ecology. Methods Adult harlequin ladybird beetles were collected from March to November from four localities in Copenhagen on different plant species. In addition, groups of last-instar larvae and pupae (n = 50) were examined for the presence of nematodes. Living and recently dead nematodes were removed from adult H. axyridis in 0.5% saline solution, the nematodes were then heat killed (at 75C), fixed in 5% formalin and transferred to glycerin on slides for further examination and measurements. Results A new species of Allantonematidae (Tylenchida), Parasitylenchus bifurcatus n. sp., is described from adults of the harlequin ladybird, Harmonia axyridis in Denmark. The new species is characterized by a straight stylet lacking basal thickenings, a bursa and a forked tail tip in the vermiform (infective) females and juvenile males. The new species is compared with P. coccinellinae previously described from ladybird beetles in France. Parasitism resulted in depletion of the fat body and partial or complete atrophy of the reproductive organs of the beetles. Infections occurred throughout the year with rates of parasitism reaching up to 35%. The rate increased to 60% when field-collected ladybirds were incubated for 30 days in the laboratory. Conclusions The production of subsequent generations within the host with only the fertilized females (not the males) leaving the hosts and the absence of parasitism of the larvae and pupae is an impressive developmental modification of P. bifurcatus . It is proposed that the vermiform (infective) females pass from one adult host to another when the beetles are hibernating or in assemblage groups. Rates of parasitism show that P. bifurcatus could be a significant biological control agent of H. axyridis .
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Parasitylenchus sp. (Tylenchomorpha: Allantonematidae) parasitizing field populations of Harmonia axyridis (Coleoptera: Coccinellidae)
European Journal of Entomology, 2011Co-Authors: Susanne Harding, George Poinar, Desislava V. Dimitrova, Tove SteenbergAbstract:Adults of the invasive harlequin ladybird, Harmonia axyridis (Coleoptera: Coccinellidae), were found to be parasitized by nematodes (Tylenchomorpha: Allantonematidae) in Denmark. The nematodes were identified as Parasitylenchus sp. Major morpho- logical characters of the nematodes did not differ significantly from Parasitylenchus coccinellinae Iperti & van Waerebeke 1968, but minor deviations in egg dimension and tail length were measured. Parasitism was only recorded in early autumn, with prevalence ranging from 2 to 33%. Adult and juvenile nematodes occurred together in the body cavity of both female and male H. axyridis.
