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ARS Home » Southeast Area » Stoneville, Mississippi » Southern Insect Management Research » Research » Publications at this Location » Publication #389296
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: Changes in functional and numerical responses of the parasitoid wasp trichogramma brassicae (hymenoptera:trichogrammatidae) over 45 generations of rearing on ephestia kuehniella

Author
item GHAEMMAGHAMI, EHSAN - TARBIAT MODARES UNIVERSITY
item FATHIPOUR, YAGHOUB - TARBIAT MODARES UNIVERSITY
item BAGHERI, ABDOOLNABI - TARBIAT MODARES UNIVERSITY
item TALEBI, ALI ASGHAR - TARBIAT MODARES UNIVERSITY
item Reddy, Gadi V.P.

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2022
Publication Date: 2/15/2022
Citation: Ghaemmaghami, E., Fathipour, Y., Bagheri, A., Talebi, A., Reddy, G.V. 2022. Changes in functional and numerical responses of the parasitoid wasp trichogramma brassicae (hymenoptera:trichogrammatidae) over 45 generations of rearing on ephestia kuehniella. Annals of the Entomological Society of America. 115:1-10. https://doi.org/10.1093/aesa/saac004.
DOI: https://doi.org/10.1093/aesa/saac004

Interpretive Summary: Trichogramma species are the most promising biological control agents for inundative releases against many lepidopteran pests. In the current study, we aimed to evaluate changes in the functional and numerical responses of T. brassicae over 45 generations of rearing on E. kuehniellaWe showed that T. brassicae was more active and foraged more frequently in the earlier generations of its mass rearing (G5 to G20), which enabled it to parasitize more eggs. These results suggest that continuous mass rearing of T. brassicae has negative effects on the foraging behavior and quality of the laboratory-reared insects, especially after G20. To reverse the negative effects of long-term mass rearing of T. brassicae, rejuvenation of the colony by periodically adding feral individuals and/or increasing frequency of releasing is strongly recommended.

Technical Abstract: We assessed the functional and numerical responses of T. brassicae under long-term rearing (45 generations, G5-15 G45) on eggs of a common factitious host, Ephestia kuehniella Zeller. Under such long-term mass rearing, the function response of this parasitoid shifted from Type III (from G5 to G20) to Type II (from G25 to G45). The maximum attack rate (T/Th) (33.62 hosts/day) and the shortest handling time (0.7138 ± 0.0272 h) were recorded in G5. Also, G45 had the lowest attack rate (21.67 hosts/day) and longest handling time (1.1076 ± 0.0689 h). The handling time increased gradually over the generations (P reg <0.01, R2 = 0.903). The number of eggs laid by the parasitoid increased significantly with increased host density but reached a plateau at very high densities. While no significant differences in daily parasitism were observed over 45 generations at densities of 2, 4, 8 and 16 available host eggs per wasp, there were significant differences in parasitism at host densities of 32, 64 and 128 eggs per wasp. Trichogramma brassicae females was more active and foraged more frequently in earlier generations (G5 to G20), which allowed wasps to parasitize more E. kuehniella eggs compared to later generations. Also, continuous mass rearing of T. brassicae negatively affected foraging behavior and the quality of wasps after G20. However, rejuvenation of the colony by adding field-collected parasitoids or rearing wasps on more suitable factitious hosts is strongly recommended to lower the negative effects of long-term mass rearing on quality of this parasitoid.