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The article focuses on the potential cost-effective use of Trichogramma parasitoids in managing Spodoptera pests, particularly the fall armyworm, which poses a significant threat to global food security. Topics include the protective scale variation on Spodoptera egg masses, the non-renewable nature of these scales, and the performance of Trichogramma species based on different egg scale thicknesses, challenging previous conclusions about their effectiveness as parasitoids.

Autoparasitoids are important biocontrol agents for controlling hemipteran pests. Females of these wasps lay fertilized eggs in whitefly nymphs (primary host) which develop as females. The males develop as hyperparasitoids from unfertilized eggs on conspecific or other primary parasitoid species (as secondary hosts). To date, the effects of mating and secondary host sex on hyperparasitism have been largely neglected. We studied heteronomous hyperparasitism of mated and unmated Encarsia sophia (Girault & Dodd) (Hymenoptera: Aphelinidae) females on different secondary hosts (conspecific or heterospecific: Eretmocerus hayati Zolnerowich & Rose (Hymenoptera: Aphelinidae)) in no-choice and paired-choice bioassays. We demonstrated that regardless of their mating status E. sophia females were unable to parasitize male secondary hosts. Although mating of E. sophia females had no effect on the number of parasitized conspecific females, the number of heterospecific females (E. hayati) parasitized by mated E. sophia was greater than in the unmated females. The mating status of E. sophia females had no effect on host feeding on conspecific secondary hosts, but it did increase host feeding on heterospecific secondary hosts (E. hayati). In no-choice bioassays, both mated and unmated E. sophia females preferred E. sophia third instar female larvae and one-day-old E. hayati female pupae as their hosts, and preferred to feed on E. sophia third instar female larvae. In paired-choice bioassays, E. sophia females preferred to feed on E. hayati male pupae over female pupae, and consumed more E. sophia female pupae than male pupae regardless of mating status. Our results suggest that mating status modulates parasitism and host feeding of E. sophia females on heterospecific secondary hosts. In addition, we demonstrated that E. sophia females are unable to parasitize secondary male hosts to produce E. sophia males. [ABSTRACT FROM AUTHOR]

The egg parasitoid Trichogramma dendrolimi Matsumura is one of the most widely used agents in sustainable crop protection to manage many lepidopteran pests in China, especially via inundative releases. It has been used as an important biocontrol agent in Integrated Pest Management (IPM) programs for the control of the plum fruit moth Grapholitha funebrana Tr. However, accurate knowledge of the parasitoid's biology and ecology is needed to optimize its practical application in pest management. In the current study, the effect of key factors on T. dendrolimi effectiveness as biocontrol agent, including host age, exposure time, parasitoid density and, host density was evaluated under laboratory conditions. The parasitoid showed a higher parasitism rate on younger over older G. funebrana eggs. When host egg density increased, the number of eggs parasitized by the parasitoid also increased, but parasitism rates decreased. The functional response of T. dendrolimi on G. funebrana eggs fitted the Holling type II Model (Nt = 0.932N/(1+0.112N)). When parasitoid density and exposure time of hosts to parasitoids increased, the parasitism rate of T. dendrolimi also increased. In addition, previous exposure of host eggs to ultraviolet (UV) light did not affect parasitism rate. All aforementioned factors did not influence the emergence rate of the parasitoid offspring. Our results would provide references for optimizing the application of T. dendrolimi inundative releases in large-scale management of G. funebrana in orchards. [ABSTRACT FROM AUTHOR]

Simple Summary: The predatory lacewing, Chrysopa pallens, a generalist predator in the field, plays an important role in sustainable, integrated pest management strategies by allowing a reduction in the use of chemical pesticides. However, the effect of mass rearing food, i.e., eggs of the rice moth Corcyra cephalonica, on the establishment of C. pallens in a banker plant system in the field is unknown. Based on the age-stage, two-sex life table, and predation rate data of C. pallens ever cultured on the C. cephalonica eggs or the aphid Megoura japonica preying on Aphis craccivora under fluctuating temperature conditions in a greenhouse, we found that C. pallens could complete their development fed on A. craccivora regardless of the food used during culture. This suggests that rice moth eggs could be provided for the mass rearing of predatory lacewings without affecting their population development and biological performance in practical applications compared with lacewings cultured on aphids. This information can serve as a basis for the application of a banker plant system with the mass reared C. pallens in the field. Banker plant systems can be used to sustain a reproducing population of biological control agents (BCAs) within a crop, thus providing long-term pest suppression. The founder population of natural enemies in banker plant systems is usually mass-reared on factitious hosts. Thus, a better understanding of the population fitness and pest control performance of mass-reared BCAs in the field is crucial when developing integrated pest management (IPM) strategies. In this study, we determined the fitness of the generalist predator, Chrysopa pallens (Hemiptera: Chrysopidae) ever cultured on different food sources (i.e., mass rearing food, Corcyra cephalonica eggs, and aphid food, Megoura japonica) preying on Aphis craccivora in a banker plant system in a greenhouse based on Chi's age-stage, two-sex life table analysis method. The life tables and predation rate parameters of C. pallens were not significantly different between both treatments under fluctuating temperature conditions. Corcyracephalonica eggs did not significantly weaken the performances of C. pallens in a Vicia faba–A. craccivora banker plant system compared to aphids. In conclusion, C. cephalonica eggs can be used for the mass production of C. pallens as the founder population in a banker plant system. Moreover, linking the life table data with the predation rate is an effective strategy for evaluating mass rearing programs in establishing banker plant systems. [ABSTRACT FROM AUTHOR]