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Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) is an important egg parasitoid of the emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). Methods for laboratory-rearing O. agrili have been developed but its mass-production depends on the continuous production and storage of freshly laid EAB eggs as well as diapaused parasitoid progeny (inside parasitized EAB eggs). The purpose of this study was to determine optimal environmental conditions for long-term storage of host eggs as well as diapaused parasitoid progeny. Fresh host eggs and diapaused parasitoid progeny were stored at two low storage temperatures (1.7 and 12.8 °C) and three levels of relative humidity (low ∼31%, medium ∼74%, and high ∼99.9%) for various length of time (15–270 days) and then evaluated for host egg suitability and the reproductive fitness of stored parasitoid progeny. EAB eggs were stored for approximately 30 days without significant reduction of their viability and suitability to O. agrili parasitism at low storage temperatures under high and medium relative humidity. Neither storage temperature or humidity had any significant effects on adult parasitoid emergence for storage durations of up to 270 days. When storage durations were over 120 days, however, both adult parasitoid longevity and fecundity declined approximately 20–30% across all temperature and humidity treatments. Relevance of findings to mass-production and storage of O. agrili for biocontrol is discussed. [ABSTRACT FROM AUTHOR]

Emerald ash borer (Agrilus planipennis Fairmaire) is an invasive primary pest of North American ash (Fraxinus spp.) trees. Blue ash (F. quadrangulata) is less susceptible to emerald ash borer infestations in the forest than other species of North American ash. Whereas other studies have examined adult host preferences, we compared the capacity of emerald ash borer larvae reared from emerald ash borer eggs in the field and in the laboratory to survive and grow in blue ash and the more susceptible green ash (F. pennsylvanica). Emerald ash borer larval survivorship was the same on both ash species. Mortality due to wound periderm formation was only observed in living field grown trees, but was low (<4%) in both green and blue ash. No difference in larval mortality in the absence of natural enemies suggests that both green and blue ash can support the development of emerald ash borer. Larvae reared from eggs on blue ash were smaller than on green ash growing in the field and also in bolts that were infested under laboratory conditions. In a laboratory study, parasitism rates of confined Tetrastichus planipennisi were similar on emerald ash borer larvae reared in blue and green ash bolts, as were fitness measures of the parasitoid including brood size, sex ratio, and adult female size. Thus, we postulate that emerald ash borer larvae infesting blue ash could support populations of T. planipennisi and serve as a potential reservoir for this introduced natural enemy after most of the other native ash trees have been killed. [ABSTRACT FROM AUTHOR]

Understanding interspecific competition among insect parasitoids is important in designing classical biological control programs that involve multiple species introductions. Spathius galinae Belokobylskij and Strazenac, a new idiobiont ectoparasitoid from the Russian Far East, currently is being considered for introduction to the United States for biological control of the emerald ash borer, Agrilus planipennis Fairmaire, whereas Tetrastichus planipennisi Yang, a koinobiont endoparasitoid native to China, is another natural enemy that already has been introduced in the same program. In a laboratory study, we examined the potential interactions between these two parasitoids when they compete for the same emerald ash borer host larvae. In multiple-choice assays where healthy emerald ash borer larvae were presented along with emerald ash borer larvae previously parasitized by T. planipennisi at different times, S. galinae attacked host larvae already parasitized by T. planipennisi for up to 4 d, but not 8 d. However, parasitism rates were significantly lower in previously parasitized hosts as compared with healthy host larvae. In no-choice tests where S. galinae females were presented either with healthy emerald ash borer larvae or emerald ash borer larvae parasitized by T. planipennisi at several earlier time points, S. galinae again parasitized significantly more healthy host larvae than T. planipennisi-parasitized larvae. These results suggest that the ectoparasitoid S. galinae can discriminate between healthy host larvae and T. planipennisi-parasitized larvae, and competitive interactions between the two parasitoids are likely to be minimal if coreleased by the emerald ash borer biological control program. [ABSTRACT FROM AUTHOR]

A dietary exposure bioassay with larvae of the ground beetle, Poecilus chalcites (Say) (Coleoptera: Carabidae), was developed to assess potential nontarget impacts of corn event MON 863 expressing the Cry3Bbl protein for control of corn rootworms, Diabrotica spp. (Coleoptera: Chrysomelidae). The assay involved 28 d of continuous exposure of P. chalcites larvae to an artificial diet treated with a maximum hazard dose (930 μg/g of diet) of the Cry3Bbl protein. Results from this study showed that the Cry3Bbl protein at a concentration of 930 μg/g of diet had no adverse effect on the survival, development, and growth (biomass) of P. chalcites larvae. Furthermore, statistical power analysis indicated that at levels of 80% power and 5% type I error rate, the study design would have been able to detect a minimum 14 (at day 7) to 19% (at days 14, 21, and 28) reduction in survival and a 21 (at day 14) to 18% (at day 28) reduction in biomass of test larvae relative to the negative buffer control groups. Based on the maximum level (93 μg/g) of the Cry3Bbl protein expressed in MON 863 corn tissues including leaves, roots, and pollen, findings from this study indicate that corn hybrids containing the MON 863 event have a minimum 10 times safety factor for larvae of P. chalcites, and thus pose little risk to this nontarget beneficial insect. [ABSTRACT FROM AUTHOR]

Responses of the opiine larval parasitoid Diachasmimorpha tryoni (Cameron) to the fruit-feeding Mediterranean fruit fly, Ceratitis capitata (Wiedemann), and the gall-forming lantana gall fly, Eutreta xanthochaeta Aldrich, were evaluated in greenhouse and open-door laboratory cages. In greenhouse cages, coffee plants containing C. capitata-infested fruit and lantana twigs containing E. xanthochaeta galls were presented to gravid D. tryoni under both choice and no-choice conditions. Regardless of the type of assay, D. tryoni strongly preferred landing on infested coffee plants to landing on galled lantana twigs. The wasp also strongly preferred landing on C. capitata-infested coffee fruits to E. xanthochaeta galls. In addition, when released directly onto a host-habitat complex, parasitoids had significantly stronger probing responses to C. capitata-infested coffee fruit than to E. xanthochaeta galls. However, the stronger probing response to coffee (shorter latency and longer duration) by D. tryoni did not result in higher rates of attack on C. capitata larvae than on gall fly larvae. When measured by the number of host larvae attacked per unit time spent probing, D. tryoni was significantly more efficient in attacking lantana gall fly larvae in stem galls than C. capitata larvae in coffee berries. When lantana patches containing galls were presented to D. tryoni in open-door laboratory cages under different regimes of availability of C. capitata or its fruit hosts, rates of attack on lantana gall flies by D. tryoni were significantly reduced by the presence of coffee plants containing C. capitata-infested berries. This result suggests that host switching of D. tryoni from C. capitata to lantana gall fly in the field is likely to be affected by the spatial and temporal distributions of the two hosts and their plant habitats. Relevance of our findings to host-switching of D. tryoni and the risk of significantly impacting populations of nontarget lantana gall flies are discussed. [ABSTRACT FROM AUTHOR]

Experiments were conducted to compare the effectiveness of 2 commercially available traps, the protein-baited McPhail trap and the fruit-mimicking Ladd trap, for capturing oriental fruit flies, Bactrocrrn dorwlis Hendel, in a commercial guava orchard. The relative attractiveness of McPhail and Ladd traps changed over seasons. In the winter of1996, Ladd traps captured more females than McPhail traps. In the spring of 1997, McPhail traps captured >-1 times as many females as Ladd traps. In the summer, fall, and winter of 1997, equal numbers of females were captured on Ladd and McPhail traps, and in the spring of 1998, McPhail traps captured >10 times as many females as Ladd traps. Ovaries of female fruit flies captured in these 2 traps were dissected and examined for the presence of mature eggs. Greater numbers of immature females were captured in McPhail traps than on Ladd traps in both 1997 and 1998. In 1997, the proportion of immature versus mature females captured in both trap types changed over seasons, with the greatest proportion of immature females being captured in the spring. We conclude that McPhail traps are a better option for growers than Ladd traps, especially in the spring when the proportion of protein-hungry flies may be greater. [ABSTRACT FROM AUTHOR]

The Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky), is a polyphagous woodboring beetle that infests and damages hardwood host trees in Asia, Europe, and North America. Native to China and the Korean peninsula, ALB is invasive in both North America and Europe. Due to the large environmental and economic impacts associated with ALB, much effort has been placed on its management and eradication from invaded areas. Eradication programs consist of visual surveys, regulatory quarantines, host removal, public outreach and education, and in some cases, insecticides. Host removal is effective but is laborious and costly, and while insecticides have been useful as a component of some eradication programs, they can be expensive, ineffective, and environmentally detrimental. Thus, several arthropod biological control agents (BCAs) have been evaluated which could support a more environmentally friendly management strategy to supplement traditional ALB management tactics. Here, we review the biological control strategy for ALB, including the exploration within the native and invaded ranges of the pest, to find potential arthropod BCAs. We discuss the ecological premise behind the method as well as the potential for its success, and we identify knowledge gaps and future considerations for the enactment of this method. While biological control shows promise, care will be needed in utilizing this method, and further research must explore the success of BCAs in field settings., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America.)