Treatment of Green Logs infested by Exotic Pest: Case Study of the Emerald Ash Borer: Agrilus planipennis Fairmaire
P Nzokou, S Tourtellot, D P Kamdem
Invasive alien insect species periodically infest forests in the United States causing the destruction of plant species and decimating populations, resulting in significant economic and ecological losses for areas involved. The Emerald Ash Borer (EAB) was first discovered on North American soil in the summer of 2002 near Detroit, Michigan and has since spread to several other Midwestern states and Ontario, Canada, causing the destruction of ash populations. Limitations posed on the circulation of green ash logs and lumber has seriously affected the economic value of ash logs and lumber in affected regions. This study investigated over bark chemicals and non-chemical treatments for sanitization of infested logs to allow free circulation and trade for value added products. Chemical treatments included borate with concentrations ranging from 5% to 16.5% (Boric Acid Equivalent) and Imidacloprid with concentration ranging from 0.005 to 0.02% applied as spray. Non chemical methods included treatments in conventional kiln and microwave at 50°C, 55°C, 60°C and 65°C.
Results obtained showed that Imidacloprid treatments concentrations of 0.01% and above were effective at sanitizing infested logs. Borate treatments resulted in significant reduction in insect emergence in indoors rearing conditions but did not achieve full control of the insect infestation. For non-chemical treatments, kiln temperatures of 65ºC were successful for sanitization of infested logs. Microwave treatments were not as effective as conventional heat for controlling insect emergence, and we hypothesized that this was due to the uneven distribution of the heat inside the microwave used in the study. Approaches to improve the microwave treatment are proposed.