Using native North American parasitoid species (Hymenoptera: Scelionidae) that often unsuccessfully attack the eggs of the invasive brown marmorated stink bug Halyomorpha halys (Hemiptera: Pentatomidae), we assessed variation in traits that may determine the parasitoids' ability to adapt to the invasive host by either exploiting or avoiding H. halys eggs (acceptance, developmental success). We also assessed variation in the parasitoids' ability to induce H. halys host egg abortion, which may contribute to biological control of H. halys in invaded areas. The first set of experiments evaluated infra- and interspecific variation using standardized laboratory tests with isofemale lines of Telenomus podisi and Trissolcus euschisti that included matching of detailed behavioural observations of acceptance with developmental outcomes. In a second set of experiments, we assessed how variation in developmental ability and abortion induction may affect levels of biological control by indigenous parasitoid species. We examined a broader sample of parasitoids that emerged from field collections of egg masses of an indigenous north American stink bug Podisus maculiventris in a region newly invaded by H. halys. Results from the first set of experiments showed high levels of acceptance of H. halys eggs among iso-female lines of parasitoids, but offspring development success was almost zero. H. halys egg abortion due to unsuccessful parasitism was often very low and varied among iso-female lines only for T. podisi. In the second set of experiments we never observed increases in abortion levels of Halyomorpha halys eggs above natural levels, even for the two species (T. euschisti and T. podisi) that were observed to oviposit in and abort H. halys eggs in the first set of experiments. We conclude that while there may be some variation in behavioural and physiological parameters mediating acceptance and abortion of H. halys eggs by native North American egg parasitoids, there does not appear to be significant variation in developmental success. Moreover, current biological control impact of H. halys eggs via host egg abortion is likely very low.

AbstractThe apple leaf midge,Dasineura mali(Kieffer) (Diptera: Cecidomyiidae), an invasive alien pest established for many years in Nova Scotia, Canada, has invaded Ontario and British Columbia, Canada apple (Malus domesticaBorkhausen; Rosaceae) orchards, damaging growing tips of trees. Molecular analysis indicated that Nova Scotia populations are genetically different from Ontario and British Columbia populations. Pheromone trap captures, oviposition on growing apple terminals, and the incidence of third instars indicate threeD. maligenerations in each province.Platygaster demadesWalker (Hymenoptera: Platygastridae), released in Nova Scotia in 1993, parasitised 34% of the third midge generation in that province and was reared fromD. malifor the first time in 2016 in the Fraser Valley of British Columbia.Lyrcus nigroaeneusAshmead (Hymenoptera: Pteromalidae) parasitised up to 21% ofD. maliin southwestern Ontario.Synopeas myles(Walker) (Hymenoptera: Platygastridae) was recorded fromD. malifor the first time, one specimen in each of Nova Scotia and Ontario, and was the most important parasitoid in British Columbia.Synopeas mylesparasitism in Okanagan and Similkameen, British Columbia orchards increased from 0% to a mean of 30% ofD. malilarvae from 2014 to 2016. Other minor parasitoids includedPlatygaster tuberosulaKieffer (Hymenoptera: Platygasteridae) in all three provinces andAphanogmus vicinusFörster (Hymenoptera: Ceraphronidae) in British Columbia.

Laboratory trials were conducted to determine whether the spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), puparium can provide an effective physical barrier to protect immature stages of the pupal parasitoid Pachycrepoideus vindemiae (Rondani) (Hymenoptera: Pteromalidae) from spinosad treatments. Spinosad insecticides are currently an important suppression strategy for D.suzukii in organically managed fruit orchards although they are well known to cause mortality in hymenopteran parasitoids. High adult P.vindemiae female mortality (83%) occurred within 24h of exposure to D.suzukii pupae treated with 10mg a.i.l(-1) spinosad and female parasitoids did not avoid the pupae treated with similar low levels of spinosad in choice tests that included untreated pupae. Pachycrepoideus vindemiae develops as an idiobiont ectoparasitoid on host fly pupa within the sclerotized host puparium. Significant P.vindemiae survival and emergence was recorded when parasitized D.suzukii puparia were exposed to field treatment levels of spinosad; however, the parasitoid survival was dependent on the time of the spinosad treatment of the host post-parasitization. Significant parasitoid survival occurred when the host puparia were treated at 2weeks when the parasitoid was in the pupal stage but did not occur when the host puparia were treated at 1week post-parasitization, when the parasitoids were still in a larval stage. The parasitoid adults consumed or otherwise came in contact with residual degrading spinosad when they exited the treated host, and consequently high and low adult parasitoid mortality occurred when the adults emerged from puparia treated at 2 and 1week(s), respectively. Our study indicates that generally the integration of P.vindemiae parasitism into a sustainable D.suzukii management program is not compatible with spinosad treatments, although P.vindemiae in the pupal stage inside sclerotized host puparia appear to be minimally impacted by spinosad treatments, provided that the spinosad degrades before parasitoid emergence.

Whole-culture extracts of Bacillus thuringiensis Berliner strains were assayed against larval and adult Drosophila suzukii (Matsumura), an important invasive pest of many thin-skinned soft fruit crops in North America. Of the 22 serovars tested versus larval D. suzukii , strains of Bacillus thuringiensis var. thuringiensis , kurstaki , thompsoni , bolivia , and pakistani caused high (75 to 100%) first-instar mortalities. Pupal mortality, measured as a failure of adults to emerge, varied with serovar. The first D. suzukii instar was the most susceptible of the three larval instars to B. thuringiensis var. kurstaki HD-1. Larval D. suzukii are shielded from crop treatments, as they develop under the skin of infested fruit, and adults would be a more vulnerable target for an efficacious strain of B. thuringiensis . Only one of the 21 B. thuringiensis serovars, var. thuringiensis , prepared as oral suspensions in sucrose for adult D. suzukii ingestion resulted in significant, albeit low mortality within 7 d. It is not a candidate for use in pest management, as it produces β -exotoxin that is toxic to vertebrates.

Exposure of Drosophila suzukii adults to surfaces treated with Metarhizium brunneum, Beauveria bassiana, Isaria fumosorosea or Lecanicillium lecanii conidia under laboratory conditions resulted in fly infection and dose dependent mortality. Scanning electron microscopy confirmed that conidia accumulated on D. suzukii pretarsi after <= 48 h exposure to the dried conidia treated surfaces. Approximately 50% of the flies died post exposure to 1 x 10(8) conidia of each isolate distributed over approximately 148 cm(2) by 7, 10, 12 and 13 days respectively at 25 degrees C. Temperature had an impact on fungus-induced D. suzukii mortality when tested at 20, 25 and 30 degrees C, although control mortality was also significant at 30 degrees C. Fifty percent of the control D. suzukii adults died after being held at 30 degrees C for 11-13 days. Significantly lower oviposition, recorded as F1 pupae, was recorded from adult D. suzukii exposed to M. brunneum compared to the number of offspring produced by control flies indicating that the fungus had a negative impact on fly fecundity. Evidence of transmission of acquired M. brunneum conidia between sexes was recorded. Crown Copyright (C) 2016 Published by Elsevier Inc. All rights reserved.

Abstract The susceptibility of immature Choristoneura rosaceana (Harris) to Beauveria bassiana-GHA (BotaniGard® 22WP) was evaluated under laboratory and field conditions. Although egg masses ≤24 h old were susceptible to infection by topically sprayed B. bassiana spores in the laboratory and resulting mycosis significantly reduced the percent of neonates able to emerge, no significant egg mass infections resulted from orchard treatment of ≤24–48 h eggs. Exposure to high levels of the B. bassiana product on apple leaf surfaces in the laboratory caused significant dose-related mortality in first to fourth instar C. rosaceana. First instar C. rosaceana were the most susceptible of the larval stages assayed in the laboratory although only 36% of neonates introduced into the orchard prior to Beauveria treatment and 27% of the neonates emerging from orchard treated egg masses became infected. Fourth instar mortalities were similar but moderate when treated with 1×108 spores mL−1 in the orchard and on leaf surfaces in the laboratory. Beauveria bassiana-induced larval mortalities were significantly higher when the spores were applied directly to the larval integument as opposed to the leaf surface where the insect would encounter the pathogen in a treated orchard. Feeding of C. rosaceana larvae on antibiotic containing meridic diet prior to their use in trials did not impact the susceptibility of the larvae to B. bassiana. Antibiotic containing meridic diet significantly reduced larval C. rosaceana mortality when treated larvae or the spores were placed directly on the diet as opposed to leaf tissue.

When last instar laboratory-reared Rhagoletis indifferens were allowed to pupate within non-sterile orchard soil containing incorporated Metarhizium brunneum isolate F52 conidia, a dose-related proportion died from developmental abnormalities and mycosis. When larvae entered soil superficially treated with M. brunneum, over 80% of the pupae died of developmental abnormalities.

Fumigation with glacial acetic acid (AA) vapor successfully kills post-harvest pathogens on tree fruits and berries and reduces their spoilage in storage. In this study, we investigated whether a similar approach could be implemented to eradicate diapausing larvae of the codling moth, Cydia pomonella (L.), from fruit harvest bins they commonly infest. In 24-h tests conducted in 0.023-m 3 fumigation chambers using two concentrations of vaporized AA (117,360 and 174,823 cumulative parts per million-hours (ppm-h)), mortality of diapausing larvae was 81% and 100%, respectively. A similar 24-h exposure to a 61,940 cumulative ppm-h treatment of AA caused no mortality. A 24-h fumigation of diapausing codling moth larvae placed in scaled-down plastic fruit bins treated with 55 mL of AA evaporated into a 1-m 3 chamber caused 100% mortality. The same fumigation treatment of artificially infested, scaled-down wooden fruit bins caused no significant mortality of test larvae. Atmospheric concentrations of AA vapor in 1-m 3 fumigation chamberscontainingwoodenbinscouldnotbemaintainedatlevelsnecessary to cause insect death, even after multiple injections of AA. We hypothesize that either the wood or the moisture contained therein absorbs or in some other way interacts with the AA vapor. The use of AA as a fumigant targeting codling moth larvae in wooden bins is not practical or economical at this time. Fumigation of plastic fruit bins with AA would provide an economical and environmentally friendly method of killing diapausing codling moth larvae. The successful disinfestations of plastic fruit bins of codling moth would prevent these binsfrom being an external source of infestation, thereby decreasing overall codling moth infestation in orchards, which in turn benefits current density- dependent management practices used for the area-wide control of codling moth. chemical name: Glacial Acetic Acid (AA).

Apple clearwing moth larvae, Synanthedon myopaeformis (Lepidoptera: Sesiidae) were found to be susceptible to infection by two entomopathogenic fungi: an indigenous fungus isolated from S. myopaeformis cadavers and identified as Metarhizium brunneum (Petch); and Beauveria bassiana isolate GHA. In laboratory bioassays, larvae exhibited dose related mortality after exposure to both the M. brunneum and Beauveria bassiana with 7 day LC50's of 2.9 x 10(5) and 3.4 x 10(5) spores/mL, respectively. Larval mortalities caused by the two isolates at 1 x 10(6) spores/mL were not significantly different and 73% of the M. brunneum-treated, and 76% of the B. bassiana-treated larvae were dead 7 days post treatment, with LT50' s of 5.5 and 5.1 days, respectively.

The impact of low levels of spinosad on the obliquebanded leafroller, Choristoneura rosaceana Harris (Lepidoptera: Tortricidae), and the koinobiont endoparasitoid, Apophua simplicipes Cresson (Hymenoptera: Ichneumonidae), was assessed when the parasitoid was in the larval stage within second- and fourth-instar hosts. These are developmental stages that would be exposed to spring orchard treatments of the insecticide. Oral spinosad LC(50) levels for unparasitized obliquebanded leafroller hosts were < 1% of the recommended orchard treatment levels. Apophua simplicipes survival was significantly reduced within parasitized spinosad-treated second- and fourth-instar larval hosts. Both the leafroller host and parasitoid were much more susceptible (ca. 65-fold) to spinosad when larval hosts fed on spinosad-treated leaf material as opposed to being treated topically. When hosts were exposed to extremely low doses of spinosad, a small percentage of parasitoids was able to survive to emerge as adults. These laboratory trials predict that applications of spinosad may reduce biological control of C. rosaceana populations by ichneumonid endoparasitoids developing within treated hosts.

Last-instar larvae of the western cherry fruit fly, Rhagoletis indifferens, were subjected to Beauveria bassiana GHA incorporated into sterile sand and non-sterile orchard soil. Mycosis in the pupal stage was observed in >20% of buried R. indifferens pupae and >80% of larvae entering sand treated with either of two B. bassiana isolates. When pre-pupal larvae burrowed into conidium-treated non-sterile cherry orchard soil, the incidence of mycosis, on both the puparia and internally developing pupae, increased with dose. Internal pupal tissues were found to contain B. bassiana. Increasing the soil moisture level from 20% to 35% water holding capacity did not have an effect on the percentage of mycosed pupae. This is the first evidence that the preimaginal stages of R. indifferens are susceptible to infection by B. bassiana.

Insect parasitoids and baculoviruses play important roles in the natural and strategic biological control of insects. The two parasites are frequent competitors within common hosts and much research has focused on the negative impact that baculoviral host infections have on parasitoids. This review summarizes the impacts that parasitoids may have on the virulence and spread of lepidopteran baculoviruses. By changing host behavior and development, parasitoids have been shown to decrease baculovirus virulence and productivity within parasitized baculovirus-susceptible hosts; however, studies of the tools used by hymenopteran parasitoids to overcome their hosts’immune systems, suggest that parasitoids may, in some cases, facilitate baculoviral infections in less susceptible hosts. Laboratory and field research have demonstrated that parasitoids can mechanically transmit baculoviruses between insects, and in this way, increase the efficacy of the viruses. Instances of new, more virulent isolates of baculoviruses have been recorded from specifically parasitoid-targeted hosts suggesting other possible benefits from the transmission or activation of baculoviruses by parasitoids.

Leafrollers can experience high levels of indigenous parasitism in organically managed apple orchards and the augmentative release of specific parasitoid species to suppress these secondary pests may be advantageous in orchards converting to non-chemical pest management. Caged and uncaged releases of two ichneumonid [Apophua simplicipes (Cresson) and Glypta variegata Dasch] and two braconid (Macrocentrus linearis Nees and Apanteles polychrosidis Viereck) koinobiont endoparasitoids of the obliquebanded leafroller, Choristoneura rosaceana (Lepidoptera: Tortricidae) on host-infested potted apple trees were conducted to assess the parasitoids' abilities to find and successfully parasitize sentinel hosts under orchard conditions. Seasonal timing of the trials varied for each parasitoid species, based on their relative performance under simulated summer/fall conditions in laboratory trials. After the release of five or fifty parasitoid females, the mean percent parasitism of leafroller larvae collected from infested trees ranged from 0 to 75% depending on the parasitoid species involved. Although caged releases tended to increase the percentage of live parasitized hosts in release treatments, uncaged releases provided a more realistic assessment of the parasitoid's ability to seek and find hosts within an infested area over a longer period. Release of the large, solitary A. simplicipes, had the most significant impact on the host population density.

The apple ermine moth, Yponomeuta malinellus Zeller, is a univoltine pest species that defoliates apple, Malus domestics (Borkh) (Rosaceae), in the temperate region of the Palaearctic. First instars overwinter within a communal hibernaculum beneath the covering of the egg batch (Kock 1998). In spring, larvae emerge to initially mine apple leaves and subsequently feed externally within a communal tent (Menken et al. 1992). During heavy infestations, the communal tents may envelop the entire apple tree, resulting in total defoliation (Parker and Schmidt 1985). There have been several accidental introductions and subsequent eradications of the apple ermine moth in eastern North America (Hewitt 1917; Parker and Schmidt 1985) but, by 1989, the pest was found in the Fraser River Valley in British Columbia, in Whatcom county, Washington, and in northwestern Oregon (Antonelli 1991; Unruh et al. 1993).

The spring leafroller complex in organically managed apple orchards in the north of the Okanagan valley in British Columbia is predominantly composed of Archips rosanus (Linnaeus) and Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), unlike the predominantly C. rosaceana and Pandemis limitata (Robinson) (Lepidoptera: Tortricidae) complex in the south of the valley. Twenty-three parasitoid species, including three possible hyperparasitoids, were reared from leafrollers in the northern organic orchards from April through June in 2001 and 2002, of which 15 of the parasitoid species represent new parasitoid records for the leafroller complex in the Okanagan valley. The most commonly reared parasitoid in the northern organic orchards, Enytus eureka (Ashmead) (Hymenoptera: Ichneumonidae), is not common in southern orchards. Meteorus trachynotus Viereck, Microgaster epagoges Gahan and Apanteles polychrosidis Viereck (Hymenoptera: Braconidae) were also frequent parasitoids within the northern leafroller complex. Apanteles fumiferanae Viereck and Macrocentrus ancylivorus Rohwer (Hymenoptera: Braconidae) as well as Glypta erratica Cresson and two unidentified species of Temelucha Förster (Ichneumonidae) were reared for the first time as leafroller parasitoids within apple orchards in British Columbia. The presumed hyperparasitoid species, Mesochorus flaviceps Provancher (Ichneumonidae) and Perilampus fulvicornis Ashmead and Perilampus prothoracicus Smulyan (Hymenoptera: Perilampidae), were also reared for the first time from this host complex. Differences in the north and south Okanagan leafroller communities and their parasitoids are discussed with respect to implications for future orchard biological control.

In laboratory trials, Glypta variegata, a common endoparasitoid of leafrollers in North America, successfully parasitized first through third instar Choristoneura rosaceana and first to fourth instar Pandemis limitata. Significantly more second instar C. rosaceana were parasitized when temperatures fluctuated between 30.3 and 12.0 degrees C (16 L: 8 D) than when temperatures fluctuated between 17.5 and 4.0 degrees C ( 12 L: 12 D), similar to fall conditions in southern British Columbia, Canada. Under the warmer simulated summer conditions, an average female wasp began to parasitize C. rosaceana 8 days post- emergence (range: 4-16 days), lived 31 days ( range: 24-37 days) and successfully parasitized 28 larvae (range: 1-89). When parasitized, C. rosaceana larvae consumed less food in their last two instars than did unparasitized female larvae.