Comparative demographics, population projections and egg maturation patterns of four eupelmid egg parasitoids on the factitious host Antherae pernyi

Authors: MU, MING-YUE - Guizhou University; CHEN, YONG-MING - Guizhou University; Wang, Xingeng; DESNEUX, NICOLAS - National Council For Scientific Research-Cnrs; ZANG, LIAN-SHENG - Guizhou University

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/10/2023
Publication Date: 5/13/2023
Citation: Mu, M., Chen, Y., Wang, X., Desneux, N., Zang, L. 2023. Comparative demographics, population projections and egg maturation patterns of four eupelmid egg parasitoids on the factitious host Antherae pernyi. Pest Management Science. https://doi.org/10.1002/ps.7537.
DOI: https://doi.org/10.1002/ps.7537

Interpretive Summary: Parasitic wasps have been the major agents successfully used for biological control against agricultural and forestry pests. Parasitic wasps attacking host eggs are arguably the most desirable agents for biological control of insect pests as they kill host pests in the egg stage, preventing the host pests from causing further damage to host plants. We comparatively evaluated the demographic parameters of four important species of egg-attacking parasitic wasps that were reared on the eggs of Japanese giant silkworm, an emerging forest pest in East China. All four species could be readily reared on this factitious host, but two of them relatively have higher control capacity for this pest than the other two species based on their population projections. We also compared some key reproductive traits of these parasitic wasps and the information gained from this study will help to improve mass rearing methods of these species in biological control programs.

Technical Abstract: The genera Anastatus and Mesocomys (both Hymenoptera: Eupelmidae) are important solitary egg endoparasitoids as biological control agents for lepidopterous and hemipterous pests worldwide. Here, we comparatively evaluated the demographic parameters of four important eupelmid egg parasitoids (Anastatus fulloi, A. japonicus, Mesocomys albitarsis and M. trabalae) reared on the factitious host eggs of the Chinese oak silkworm Antheraea pernyi, using age-stage two-sex life tables, their population projections as well as egg maturation patterns. Both the age-specific net reproductive rate (lxmx) and reproductive value (vxj) increased initially and then gradually decreased with increasing age in all four parasitoid species. Overall, the two Mesocomys species had higher survival rates at stable age-stage distribution, peak reproductive values, and intrinsic rates of increase than the two Anastatus species. Mesocomys albitarsis had the longest longevity while A. japonicus had the longest oviposition days and mean generation time. The two Mesocomys species are thus projected to have faster population increase than the two Anastatus species. Adult females of all four parasitoid species emerged with only a few mature eggs (< 6 eggs) and most of their eggs were matured post-emergence (i.e., strict synovigeny). The estimated 90% of lifetime complement of reproduction (offspring) and realized days were 374 and 32 for A. japonicus, 337 and 22 for M. trabalae, 330 and 19 for M. albitarsis and 147 and 28 for A. fulloi. Our results indicated that the two Mesocomys species have higher control capacity than the two Anastatus species. Provision of adult food for these strictly synovigenic parasitoids would be essential to prolong their lifespan and continuously produce eggs for parasitizing their hosts in mass rearing or augmentative biological control programs.