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ARS Home » Southeast Area » Stoneville, Mississippi » Southern Insect Management Research » Research » Publications at this Location » Publication #424451
Research Project: Insect Control and Resistance Management in Corn, Cotton, Sorghum, Soybean, and Sweet Potato, and Alternative Approaches to Tarnished Plant Bug Control in the Southern United States

Location: Southern Insect Management Research

Title: Effects of successful or unsuccessful parasitism by the solitary endoparasitoid wasp Cotesia vestalis (Hymenoptera: Braconidae) on the testis development in several host moth species

Author
item HIROYOSHI, SATOSHI - Tokyo University Of Agriculture & Technology
item MITSUNAGA, TAKAYUKI - National Agriculture And Food Research Organization (NARO), Agricultrual Research Center
item Reddy, Gadi

Submitted to: Journal of Insect Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/8/2025
Publication Date: 4/11/2025
Citation: Hiroyoshi, S., Mitsunaga, T., Reddy, G.V. 2025. Effects of successful or unsuccessful parasitism by the solitary endoparasitoid wasp Cotesia vestalis (Haliday) (Hymenoptera: Braconidae) on the testis development in several host moth species. Journal of Insect Physiology. 163(06):1-8. https://doi.org/10.1016/j.jinsphys.2025.104808.
DOI: https://doi.org/10.1016/j.jinsphys.2025.104808

Interpretive Summary: Parasitism by parasitoids affects their hosts in several ways, including delaying development, altering body weight, blocking encapsulation by hemocytes, modifying behavior, castrating testes, and ultimately causing death. This study explores the reasons and mechanisms behind the suppression of testis development due to unsuccessful parasitism in relation to ecdysteroid and parasitism. Our findings suggest that testis development in several examined moth species was suppressed by parasitoid wasps, regardless of the parasitism's success or failure. The results indicate that parasitism suppresses testis development, irrespective of the outcome. The study discusses the reasons and mechanisms behind the suppression of testis development by unsuccessful parasitism, focusing on ecdysteroid and parasitism.

Technical Abstract: Parasitism by a parasitoid wasp affects the physiology and behavior of host insects. In this study, we examined the impacts of successful and unsuccessful parasitization on individual and testis development in several host moth species. The endoparasitoid wasp, Cotesia vestalis (Haliday) (Hymenoptera: Braconidae), primarily parasitizes the diamondback moth (Plutella xylostella L.) (Lepidoptera: Plutellidae), although its host range is relatively broad. In a previous study, we demonstrated that this wasp successfully parasitized DBM, Mythimna separata Walker (Noctuidae), and Helicoverpa armigera armigera (Hübner) (Noctuidae), whereas it failed to parasitize Spodoptera exigua (Hübner) (Noctuidae), Palpita nigropunctalis (Bremer) (Pyralidae), Aedia leucomelas (L.) (Noctuidae), and Mamestra brassicae (L.) (Noctuidae). In this study, we found that testis development in all parasitized host species, except for A. leucomelas, was suppressed compared to the unparasitized controls. However, the testes grew to some degree after parasitization, depending on the host species, except for DBM, independent of ecdysis. These results indicate that testis development is suppressed by parasitism, irrespective of the success or failure of parasitization. The study discusses the reasons and mechanisms behind the suppression of testis development by unsuccessful parasitism, focusing on ecdysteroid and parasitism.