Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2020
Publication Date: 11/9/2020
Citation: Duan, J.J., Schmude, J.M., Larson, K.M. 2020. Effects of low temperature exposure on diapause, development, and reproductive fitness of the Emerald Ash Borer (Coleoptera: Buprestidae): Implications for voltinism and laboratory Rearing. Journal of Economic Entomology. https://doi.org/10.1093/jee/toaa252.
Interpretive Summary: The emerald ash borer (EAB), native to Northeast Asia, is the most destructive invasive ash tree pest in North America. EAB larvae are dormant in the fall and winter and take one to two years to complete a generation in the field. The beetle’s dormancy and extended life cycle present challenges to laboratory rearing of this beetle. We determined the optimal conditions (chill treatments) needed to terminate the dormancy of EAB larvae. This information will facilitate the continuous production of this beetle for research and biocontrol purposes.
Technical Abstract: The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), native to Northeast Asia, is the most destructive invasive ash (Fraxinus spp.) pest in North America. In the present study, we exposed mature 4th instars (J-shaped larvae, JL) of the emerald ash borer to either 1.7oC or 12.8oC for 1 – 9 months, subsequently evaluated their post-chill development to adults, and assessed the longevity and lifetime fecundity of the emerging adult beetles under normal (warm) rearing conditions (26 ± 0.5oC, 16:8 h L:D). In addition, we determined the effect of different stages of EAB larvae chilled at 12.8oC for 3 months on the subsequent post-chill development to adult beetles. Findings from the study revealed that a period (> 2 months) of chill at 12.8oC is required for the termination of the EAB diapause. However, chill treatment of the EAB larvae at the near zero temperature (1.7oC) does not result in the post-diapause larval development to adults, regardless of the chill time (1 – 9 months). In addition, our results showed that chill treatment of immature young larvae (L1 – L3, non JL) results in little production of adult beetles, indicating that EAB diapause predominantly as JL. These findings are relevant to the development of effective laboratory rearing protocols for production of adult beetles from eggs through continuous generations and help us understand the EAB voltinism resulting from the diapause development under different climatic conditions.