|Golec, Julian - University Of Delaware|
|Hough-goldstein, Judy - University Of Delaware|
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/12/2017
Publication Date: 6/8/2017
Citation: Golec, J.R., Duan, J.J., Hough-Goldstein, J. 2017. Influence of temperature on the reproductive and developmental biology of Ontsira mellipes (Hymenoptera: Braconidae): Implications for biological control of the Asian Longhorned Beetle (Coleoptera: Cerambycidae). Environmental Entomology. 46(4):978-987. doi:10.1093/ee/nvx100.
Interpretive Summary: The stingless, parasitic wasp (Ontsira mellipes) is a North American parasitoid that develops on the invasive Asian longhorned beetle (ALB) under laboratory conditions. This native natural enemy is currently being considered as a potential new-association biocontrol agent and may be used to complement the current ALB eradication program in the US. To better understand its biology and improve outcomes of mass-rearing, scientists from USDA Agricultural Research Service and University of Delaware determined the optimal ambient temperature for immature development and adult longevity and fecundity. Results from our study show that when they are maintained at a range of temperatures from 10 to 30°C for their lifetimes, the female wasps have the highest net reproductive rate, greatest longevity and fecundity at 25oC. These findings will significantly contribute to the development of efficient rearing protocols for mass production of this natural enemy for field releases against the invasive Asian longhorned beetle.
Technical Abstract: Ontsira mellipes Ashmead (Hymenoptera: Braconidae) is a North American parasitoid that develops on the invasive pest, Anoplophora glabripennis (Moltschulsky) (Coleoptera: Cerambycidae) under laboratory conditions, and is currently being considered as a potential new-association biocontrol agent. In order to develop mass rearing protocols for this parasitoid, information on its reproductive biology in relation to temperature is needed. This study examined the effect of temperature (10, 15, 20, 25, and 30°C) on immature development, survivorship, and sex ratio as well as adult longevity, fecundity and host attack rate (parasitism). The development rate from egg to adult significantly increased from 0.02 to 0.06 as temperature increased from 15 to 30°C, corresponding to adult eclosion that was completed in ~ 7, 4, 3, and 2 weeks in 5°C increments from 15 to 30°C . No adults emerged after ~ 2 months at 10°C. The lower development temperature threshold and degree-days required for one generation were calculated at ~ 360 days above 7.5°C. When female parasitoids were provided with host larvae, parasitism occurred at all temperatures. The probability of host attack (parasitism) increased with increasing temperature. Additionally, increasing temperatures significantly reduced the pre-oviposition period, longevity, and lifetime fecundity of female O. mellipes. Because immature survival and parasitism was maximized at 25°C, we recommend this rearing temperature. Combining these results with temperature data from areas currently infested with A. glabripennis, climate conditions in these locations appear adequate for parasitization and development of O. mellipes and may support one to two generations of this parasitoid per year.