Project Number: 8010-22000-028-26-I
Project Type: Interagency Reimbursable Agreement
Start Date: May 1, 2018
End Date: Sep 30, 2020
The goal of the proposed research is to develop biological control approaches to supplementing the current eradication and/or management strategy against ALB. Using the knowledge base of the native North American hymenopteran parasitoid O. millipes, we will first evaluate the host specificity of the parasitoid reared on ALB larvae for over 50 generations and then determine the potential efficacy of the laboratory-reared, ALB-adapted O. millipes in suppressing ALB populations under field-cage and/or open-field conditions. The proposed research will lead to further development of effective (new-association) biological control approaches that would be complementary to the current ALB eradication and management strategy.
We have established several populations of O. mellipes collected between 2011 and 2013 in the mid-Atlantic area from maple (Acer spp.) trees naturally infested with native North American species of longhorned beetles. These parasitoid populations have been reared on ALB larvae for different generations under laboratory conditions at USDA ARS Beneficial Insects Introduction Research Unit (BIIRU) quarantine facility (Newark, DE). For this research, however, we will use populations of O. mellipes that has been reared on ALB for at least 50 generations. To assess the host specificity of O. mellipes, we will focus on testing common species of native North American longhorned beetles (Coleoptera: Cerambycidae) infesting major hardwood trees such as maple, birch, and oak. Live adults of different species of North American cerambycids will be collected between May and August each year from the hardwood forests in mid-Atlantic and/or Northeast United States using longhorned beetle traps developed by USDA APHIS Otis laboratory. Adults of different species of native longhorned beetles collected from the traps will then be reared with foliage or twigs of their preferred host plants and sugar water and provided with host logs or other substrates for oviposition at the USDA APHIS Otis laboratory or the USDA-ARS facility in Newark, DE. Native longhorned beetle larvae will be reared on artificial diet until they are of a size comparable to the size of ALB parasitized by O. mellipes (instar 2-3). Once a suitable size is reached, the larvae will be inserted in logs of the appropriate host tree for testing. We will expose gravid females of O. mellipes to suitable larval stages (2 – 3rd instars) of different species of native North American cerambycids using the similar procedures described by Duan et al (2015) and Golec et al. (2016). We are targeting testing the major native longhorned beetle species infesting maple, oak, and/or birch trees and determine the potential native host range of O. mellipes. Following host specificity testing, we will conduct series of experiments under field-cage or open field conditions in ALB-infested (quarantined) areas (Wooster, MA and Clement, OH) to evaluate the efficacy of laboratory-reared, ALB-adapted O. mellipes in parasitizing ALB larvae infesting maple logs or live trees. Because host specificity testing will take one to two years depending on success in collecting and rearing beetles, field tests will not occur in 2018. USDA APHIS PPQ Otis laboratory has developed trapping and rearing methods for many native species of longhorned beetles and will be providing eggs or larvae of the nontargted longhorned beetles for host-specificity testing with O. mellipes at USDA ARS BIIRU.