Pachycrepoideus Vindemmiae Rondani Research Articles

Resident Hymenopteran Parasitoids with Potential Drosophilid Associations in Andean North Patagonia: Implications for the Biological Control of the Spotted Wing Drosophila.

The spotted wing drosophila, Drosophila suzukii Matsumura, is native to Southeast Asia and has become a serious pest of soft-skinned fruits worldwide. Several control methods are being tested worldwide as part of an integrated pest management approach. Biological control is a promising alternative tactic that can be used to manage D. suzukii populations, especially in unmanaged areas. This study aimed at exploring the diversity of resident hymenopteran parasitoids of drosophilids in northwestern Patagonia, where D. suzukii is considered an important pest. The survey also aimed to investigate possible associations between parasitoids and D. suzukii in several crops and non-crop fruits, and to determine D. suzukii fruits infestation levels. Fourteen sites with mainly berry crops were sampled biweekly using cider vinegar traps and collecting fresh fruits from a variety of crop and non-crop fruit plants. We identified five species of hymenopteran parasitoids, obtained from the baited traps, that have the potential to associate with D. suzukii: Leptopilina heterotoma Thomson, Ganaspis brasiliensis Ihering, Hexacola hexatoma Hartig (Figitidae), Pachycrepoideus vindemmiae Rondani (Pteromalidae), and Spalangia endius Walker (Spalangiidae). Leptopilina heterotoma is reported for the first time in Argentina. High numbers of D. suzukii adults were recovered from baited traps and field-collected fruits. However, no parasitoid emerged from D. suzukii pupae recovered from fruits, nor were any dead parasitoids recorded inside D. suzukii pupae. Overall infestation levels of D. suzukii on field-collected fruits did not differ significantly between species/varieties. The results are discussed with emphasis on the possible functionality and perspectives of using these species as biological control agents.

Intrinsic competition between 2 pupal parasitoids of Drosophila suzukii (Diptera: Drosophilidae)

Abstract The parasitoids Pachycrepoideus vindemmiae Rondani (Hymenoptera: Pteromalidae) and Trichopria anastrephae Costa Lima (Hymenoptera: Diapriidae) have great potential in controlling Drosophila suzukii (Matsumura); however, both, compete for the same resources. In this study, we evaluated whether the different stages of development of the primary parasitoid reduce the negative effect of intrinsic competition. For this, we first defined the duration of each immature stage of both parasitoid species and then offered D. suzukii pupae containing the first parasitoid (P. vindemmiae or T. anastrephae) at different stages of development to the second parasitoid (P. vindemmiae or T. anastrephae). We also checked the second parasitoid’s preference (P. vindemmiae or T. anastrephae) for the primary parasitoid at different stages of development (P. vindemmiae or T. anastrephae) or D. suzukii pupae nonparasitized. Our evaluations showed that T. anastrephae preferred to parasitize pupae that were not previously parasitized and that had not parasitized puparia of D. suzukii when P. vindemmiae was in later stage to the 1st instar. However, P. vindemmiae preferred to parasitize pupae previously parasitized by T. anastrephae. In an environment of intrinsic competition, the first parasitoid to parasitize has an advantage, except when the pupal stage of T. anastrephae is parasitized by P. vindemmiae. The variation in the parasitoids’ oviposition time mitigates the competition effect; however, for use in biological control programs, the hyperparasitoids P. vindemmiae, does not prove to be advantageous, as they can affect the establishment of primary parasitoids such as T. anastrephae, and can act as competitors for resources.

Diversity of parasitoids associated with fruit flies on cultivated and wild plants in southern Togo

Fruit flies (Diptera: Tephritidae) are major constraints on the production and marketing of fruits in African tropical and subtropical countries. In a perspective to manage these fly pests, an inventory of parasitoids associated with fruit flies was carried out from 2009 to 2011 in southern Togo through various fruit incubations. Nine species of native hymenopteran parasitoids associated with eight fly species belonging to five genera Bactrocera, Ceratitis, Dacus, Trirhithrum and Zeugodacus were recovered. Trichopria sp. (Diapriidae) was the most abundant parasitoid. However, the numbers of Braconidae (Diachasmimorpha fullawayi Silvestri, Fopius caudatus Szepligeti and Asobara sp.), Figitidae (Aganaspis sp.), Pteromalidae (Pachycrepoideus vindemmiae Rondani and Spalangia sp.), Eulophidae (Tetrastichus giffardianus Silvestri) and Chalcididae (Dirhinus giffardii Silvestri) species were relatively low. The rate of parasitism of different species of recovered parasitoids ranged from 0.6 to 40%. This is an asset for future surveys in the center and northern regions and studies of interactions between fruit flies and their natural enemies in Togo.

Diversity and Abundance of House Fly Pupal Parasitoids in Israel, with First Records of Two Spalangia Species.

Filth flies (Diptera: Muscidae), particularly the house fly, Musca domestica L., are global pests of livestock production. In this study, we characterized the fauna of house fly pupal parasitoids in Israel and identified factors affecting their diversity and abundance. The study, which included one round of sampling during the fall of 2013 and another round of sampling in the spring of 2014, encompassed 26 locations of common fly-breeding habitats: dairy, egg-laying, and goat farms throughout Israel. Nine parasitoid species were found: Spalangia cameroni Perkins, Spalangia endius Walker, Spalangia drosophilae Ashmead, Spalangia gemina Boucek, Spalangia nigroaenea Curtis, Pachycrepoideus vindemmiae Rondani, Muscidifurax raptor Girault and Sanders, Muscidifurax zaraptor Kogan & Legner (all Hymenoptera: Pteromalidae), and Dirhinus giffardii Silvestri (Hymenoptera: Chalcididae). This is the first record of S. gemina from the Palearctic, as well as the first record of S. drosophilae from the Middle East. The composition and relative abundance of parasitoid species varied markedly among localities, climatic regions (Mediterranean vs. desert), habitat types (dairy vs. egg-laying vs. goat farm), and seasons. Overall, parasitoid richness in egg-laying farms was two- and sevenfold higher than in dairy and goat farms, respectively, and three times higher in Mediterranean than desert climate. The significance and implications of our results for inundative biological control programs of filth flies are discussed.

Pachycrepoideus vindemmiae(Hymenoptera: Pteromalidae) as a Potential Natural Enemy of Maize-Infesting Ulidiidae

Euxesta annonae Fabricius, E. eluta Loew, E. stigmatias Loew, and Chaetopsis massyla Walker (Diptera: Ulidiidae) are primary sweet corn pests in Florida. Few natural enemies of these flies are known. The pupal parasitoid Pachycrepoideus vindemmiae Rondani (Hymenoptera: Pteromalidae) was discovered in a laboratory colony of E. eluta and E. stigmatias, and its potential as a biological control agent was studied. Development times in fresh, chilled, and frozen E. eluta pupae were recorded. Fly larvae were allowed to dig into soil to pupate, and pupae covered by 2.5 cm of soil were presented to wasps to determine if P. vindemmiae could locate them. Finally, to evaluate susceptibility to insecticides commercially used in ear-stage sweet corn, adult parasitoids were caged on maize leaves treated with chlorpyrifos, methomyl, or zeta cypermethrin for 24 h. Pachycrepoideus vindemmiae completed development in normal, chilled, and frozen fly pupae in 15–17 days. None of the fly pupae covered by soil were parasitized. Chlorpyrifos and methomyl residues killed >95% of P. vindemmiae within 24 h. Zeta cypermethrin was slower acting, but resulted in 50% mortality after 24 h. Therefore, P. vindemmiae does not appear to be well suited as an effective biological control agent of maize-infesting Ulidiidae in sweet corn fields. This is the first known account of this cosmopolitan parasitoid attacking maize-infesting ulidiids.

Effects of Host Age on the Parasitism ofPachycrepoideus vindemmiae(Hymenoptera: Pteromalidae), an Ectoparasitic Pupal Parasitoid ofBactrocera cucurbitae(Diptera: Tephritidae)

ABSTRACT Biological control using an ectoparasitic idiobiont (e.g., Pachycrepoideus vindemmiae Rondani) (Hymenoptera: Pteromalidae) can be an effective approach to reduce the economic losses caused by the melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae). In this study, we determined the parasitism of P. vindemmiae on B. cucurbitae pupae of different ages. The results showed that B. cucurbitae pupae at all ages could be successfully parasitized by P. vindemmiae. The higher numbers of pupae parasitized (10.12 to 9.32 pupae/day for no-choice tests and 8.0 to 7.82 pupae/day for choice tests) were achieved when 3 or 4-day old pupae were used as hosts. The selection coefficient revealed that P. vindemmiae preferred 3 or 4-day old pupae as the host. Pachycrepoideus vindemmiae females developed more quickly on 3 or 4-day old hosts than on pupae of other ages. Longevity of parasitoid offspring obtained from 2 and 7-day old melon fly pupae varied from 9.45 to 10.37 days and from 8.97 to 9.45 day...

Manejo integrado de plagas como estrategia para el control de la mosca del botón floral del maracuyá Dasiops inedulis Steyskal (Diptera: Lonchaeidae)

En el presente estudio se colectaron cuatro parasitoides de Dasiops inedulis Steyskal (Diptera: Lonchaeidae), i.e., uno de tipo larva-pupa identificado como Utetes anastrephae (Viereck) (Hymenoptera: Braconidae), y tres parasitoides de pupas identificados como Pachycrepoideus vindemmiae Rondani, Spalangia sp. (Hymenoptera: Pteromalidae) y Aganaspis sp. (Hymenoptera: Figitidae). En el campo se observaron daños ocasionados por una larva de Chrysopidae (Neuroptera) sobre pupas centinelas deD. inedulis. Se realizaron experimentos con un cebo tóxico de origen natural a base de Saccharopolyspora spinosa en los municipios de Palmira y Toro, en el departamento del Valle del Cauca, destacándose como una nueva alternativa para el control de D. inedulis en maracuyá amarillo, ya que en las dos localidades mantuvo los niveles de daño por debajo del manejo convencional del agricultor y el testigo absoluto. Se provee una lista de enemigos naturales de D. inedulis tomada mediante muestreos de botones florales de maracuyá, uso de pupas centinelas, e información en la literatura científica. Para el control de la mosca del botón floral del maracuyá, D. inedulis, se propone una estrategia de manejo integrado de plagas que le permitirán al productor mantener las poblaciones de D. inedulis reguladas con diferentes herramientas, i.e., enemigos naturales que se pueden incorporar en diferentes etapas de la fenología de D. inedulis, uso de cebos tóxicos de baja toxicidad, recolección de botones con síntomas de daño, y monitoreo con el uso de trampas McPhail cebadas con proteína hidrolizada, interviniendo en diferentes estados de desarrollo, cortando ciclos y disminuyendo así futuras generaciones del insecto.

Does Host Value Influence Female Aggressiveness, Contest Outcome and Fitness Gain in Parasitoids?

AbstractIntraspecific competition for resources is common in animals and may lead to physical contests. Contest outcomes and aggressiveness can be influenced by the resource holding potential of contestants but also by their perception of the resource value (RV). Competitors may assess resource quality directly (real RV) but may also estimate it according to their physiological status and their experience of the habitat quality (subjective RV). In this article, we studied contests between females of the solitary parasitoidPachycrepoideus vindemmiaeRondani (Hymenoptera: Pteromalidae) when exploiting simultaneously a host, aDelia radicumL. (Diptera: Anthomyiidae) pupa. We tested the effect of factors modifying host value on the occurrence of agonistic behaviours, contest outcomes and host exploitation. The factors tested were: the quality of the previous habitat experienced by females, female egg load, host parasitism status and the stage reached by the owner female in her behavioural oviposition sequence. Females successfully protected their host against intruders during its exploitation, but not after oviposition, and their aggressiveness did not seem to be influenced by their perception of the RV. The fact that the host is subsequently parasitized by the opponent females appears to mainly depend on the host selectiveness of females.

Intraspecific Variations in Host Discrimination Behavior in the Pupal Parasitoid <I>Pachycrepoideus vindemmiae</I> Rondani (Hymenoptera: Pteromalidae)

In solitary parasitoid species, superparasitism incurs a high cost because only one individual can emerge per host. While avoiding already-parasitized hosts seems advantageous, it requires an ability to discriminate between parasitized and unparasitized hosts. The ability to discriminate can be based on physical or chemical cues or signal associated either internally or externally with a given host. The type of stimuli used to recognize parasitized hosts generally depends on the features of these hosts but also on costs and benefits associated with reusing them. Some local factors such as mortality rate of females, host availability, and competition level can influence this trade-off. In species that occupy a large geographic range, local conditions may favor either external or internal mechanisms of host discrimination. We describe the behaviors associated with host discrimination in Pachycrepoideus vindemmiae Rondani (Hymenoptera: Pteromalidae), a solitary pupal parasitoid of cyclorraphous dipteran species. To detect potential intraspecific variability in their host discrimination behavior, we compared two P. vindemmiae populations originating from different geographical areas in France. Our results revealed different host discrimination strategies in both populations and indicated a potential trade-off between the speed and the accuracy of host discrimination. One population discriminated hosts externally (faster but less accurately), whereas the other discriminated internally (more slowly but more accurately). In our experimental conditions, these two strategies resulted in differences in the fitness gains of both populations. The ecological conditions that could have selected for such differences in the host discrimination and oviposition strategies of the two populations remain to be investigated.

Selection Strategies of Parasitized Hosts in a Generalist Parasitoid Depend on Patch Quality but Also on Host Size

Host rejection, superparasitism, and ovicide are three possible host selection strategies that parasitoid females can adopt when they encounter parasitized hosts. These differ in costs (in terms of time and energy required) and benefits (in terms of number and quality of offspring produced). Their relative payoff should vary with patch quality, (i.e., proportion of parasitized hosts present), and female choice between them should be adapted accordingly. We conducted behavioral observations to test the effect of the ratio of parasitized/unparasitized hosts present in a patch on the host selection strategies of Pachycrepoideus vindemmiae Rondani (Hymenoptera: Pteromalidae). This species being a generalist known to attack hosts of a great range of size, we also tested the impact of host size on female decisions with two host species differing greatly in size (Drosophila melanogaster and Delia radicum). We evaluated the adaptive value of each strategy in relation to host parasitization status and host size by measuring their duration and the potential number of offspring produced.

Survey of Microhymenoptera (Hymenoptera: Chalcidoidea) Parasitizing Filth Flies (Diptera: Muscidae, Calliphoridae) Breeding in Refuse and Poultry Farms in Peninsular Malaysia

Nine species of parasitoids were found parasitizing the pupae of filth flies breeding in refuse dumps and poultry farms throughout peninsular Malaysia. Spalangia were most common, consisting of Spalangia endius Walker, S. cameroni Perkins, S. gemina Boucek, S. nigroaenea Curtis, and two undescribed species. Other parasitoids collected were Pachycrepoideus vindemmiae Rondani, Dirhinus himalayanus Westwood, and an unidentified Hymenoptera. The parasitized fly hosts included Musca domestica L., Chrysomya megacephala (F.), Fannia sp., and Ophyra sp. S. endius was the most common parasitoid attacking M. domestica and C. megacephala at refuse dumps and poultry farms D. himalayanus were found to parasitize only M. domestica pupae collected at poultry farms.