Location: Beneficial Insects Introduction Research Unit
Project Number: 8010-22000-031-093-I
Project Type: Interagency Reimbursable Agreement
Start Date: Jun 30, 2024
End Date: Jun 29, 2025
Objective:
Goals: The proposed research aims to rear and identify a genetic line of the introduced parasitoid Spathius agrili from established sites in Tennessee (or other sites in the southern US) that have been adapted to a warmer climate and may be thus effective for field releases against EAB in southern US.
Objectives:
1. Collect and rear Spathius parasitoids from established sites in Tennessee and confirm their identity as S. agrili.
2. Rear S. agrili to send to the USDA-APHIS EAB Biocontrol Rearing Facility for mass production and field releases against EAB.
Approach:
All parasitoid rearing will be conducted in reach-in environmental chambers under normal rearing conditions (~25C, 65% RH, and long day photoperiod – 16:8 hrs L:D). To rear EAB parasitoids (Spathius agrili) collected from different sites or regions, we will first need to rear late instar EAB larvae on tropical ash bolts (diam ~1.5 cm x length ~ 15 cm) infested with EAB eggs. Newly emerging female and male wasps of S. agrili will be first hosted together in rearing cages for a week and then exposed to EAB-infested tropical ash bolts for another week. After parasitoid exposure, exposed ash bolts will be moved to clean containers and incubated under normal rearing conditions for adult emergence (normally 4 – 6 weeks post parasitoid).
After adult wasp emergence, voucher specimens (5-10) from each site will be collected and preserved in molecular alcohol and sent to USDA-APHIS Forest Pest Methods Laboratory (FPML) for morphological and DNA identification. Once authoritative identification is confirmed, the above rearing procedure will be repeated for one or more generations to produce large quantities of adult wasps that will be sent to the USDA-APHIS EAB Biocontrol Rearing Facility for mass production and field releases against EAB.
If resources are available, laboratory experiments will also be conducted to compare (1) the reproductive biology of Spathius agrili collected from different sites or regions, and (2) the developmental time/rates as well as diapausing behavior of parasitoid progeny produced from different populations.
