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ARS Home » Northeast Area » Newark, Delaware » Beneficial Insects Introduction Research Unit » Research » Publications at this Location » Publication #292229
Title: Effects of ambient temperature on egg and larval development of the invasive emerald ash borer (Coleoptera: Buprestidae): implications for laboratory-rearing

Author
item Duan, Jian
item WATT, TIMOTHY - University Of Delaware
item Taylor, Philip
item LARSON, KRISTI - University Of Delaware
item LELITO, JONATHAN - Animal And Plant Health Inspection Service (APHIS)

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/27/2013
Publication Date: 10/1/2013
Citation: Duan, J.J., Watt, T., Taylor, P.B., Larson, K., Lelito, J. 2013. Effects of ambient temperature on egg and larval development of the invasive emerald ash borer (Coleoptera: Buprestidae): implications for laboratory-rearing. Journal of Economic Entomology. 106/1-8.

Interpretive Summary: Emerald ash borer is an insect pest that has killed millions of ash trees (Fraxinus spp.) in North America since being discovered in Michigan in 2002, and the management of EAB is projected to cost over $10 billion in the coming decade. Historically, there has been no effective method to rear this forest pest in the laboratory because of its long life cycle and cryptic nature of immature stages. This lack of effective laboratory-rearing methods has not only hindered research into its biology and ecology, but also mass-production of natural enemies for biological control of this invasive pest. Using sticks from an alternate host plant (evergreen ash), we investigated the stage-specific development time and/or growth rate of emerald ash borer eggs and larvae at different constant temperature treatments (12 – 35 deg C) for the purpose of developing effective laboratory-rearing methods. Our research findings showed that ambient temperature strongly influence the developmental time of both emerald ash borer eggs and larvae. The optimal range of ambient temperature to rear emerald ash borer larvae on evergreen ash are between 25 and 30 deg C with faster rates of egg and larval development at higher temperature within this range. This information is not only important to our understanding of emerald ash borer ecology (e.g., the effect of climatic condition on its population growth), but also critical to production of suitable stages of larvae for various research programs such as mass-rearing egg and larval parasitoids for biological control of this invasive pest.

Technical Abstract: The emerald ash borer, Agrilus planipennis Fairmaire, an invasive beetle from Asia causing large scale ash (Fraxinus spp.) mortality in North America, has been extremely difficult to rear in the laboratory because of its long life cycle and cryptic nature of immature stages. This lack of effective laboratory-rearing methods has not only hindered research into its biology and ecology, but also mass-production of natural enemies for biological control of this invasive pest. Using sticks from the alternate host plant, F. uhdei (Wenzig) Lingelsh, we characterized the stage-specific development, time and/or growth rate of emerald ash borer eggs and larvae at different constant temperature treatments (12 – 35 deg C) for the purpose of developing effective laboratory-rearing methods. Results from our study showed that the median time for egg hatching decreased from 20 days at 20 deg C to 7 days at 35 deg C, while no emerald ash borer eggs hatched at 12 deg C. The developmental time for 50% of emerald ash borer larvae advancing to 3rd, 4th, and J-larval stages at 20 deg C were 8.3 weeks, 9.1 weeks, and 12.3 weeks, respectively, approximately two times longer than at 30 deg C for the corresponding instars or stages. In contrast to 30 deg C, however, the development times for emerald ash borer larvae advancing to later instars (from oviposition) were significantly increased at 35 deg C, indicating adverse effects of this high temperature. Therefore, when developing protocols to rear late instars of emerald ash borer larvae, we suggest that the maximum ambient temperature should not be higher than 30 deg C. The optimal range of ambient temperature to rear emerald ash borer larvae should be between 25 – 30 deg C; however faster rate of egg and larval development should be expected as temperature increases within this range.