(1st Place) Efficacy and residual toxicity of chitosan for Rhagoletis pomonella (Diptera: Tephritidae)

Chitosan is a naturally derived polymer which has significant potential for use as a bioinsecticide. Despite this, there is a lack of research as to the efficacy of chitosan for many insect pests. The apple maggot fly, Rhagoletis pomonella (Walsh) (Diptera: Tephritidae), is one of such pests for which chitosan toxicity has not been explored. This study found that chitosan is toxic for R. pomonella adults when ingested, leading to a significant increase in their rate of mortality. Effective biopesticide delivery systems have not been explored for chitosan use outside of a laboratory, indicating the need for further research testing delivery mechanisms. It is suggested that an effective method of delivery will be as a food-based bait in attract-and-kill traps, as chitosan must be ingested in order to kill flies. Forming a viscous solution, chitosan will be best suited to these lure systems. An aging trial revealed that R. pomonella did not experience increased mortality due to placement with aged chitosan-sucrose treatments.