Responses of apple maggot (Diptera: Tephritidae) to ammonium hydroxide lures

Abstract

Ammonia has long been known to be an attractant for the apple maggot, Rhagoletis pomonella (Walsh) (Diptera: Tephritidae) (Hodson 1943, 1948). The responses of apple maggot to ammonia release rates, however, have not been adequately determined. Ammonia release rates determined from mass losses of ammonium carbonate, ammonium acetate, and casein hydrolysate lures (e.g., Jones 1988; Reynolds and Prokopy 1997) do not take into account decomposition and release of compounds such as carbon dioxide or volatiles that may be moderately repellent (Bateman and Morton 1981; Mazor et al. 1987) or attractive to some Tephritidae flies (Mazor et al. 1987). In this study, the objectives were to determine the responses of apple maggot females and males in western Washington to ammonium hydroxide lures designed to release a wide range of ammonia. An emphasis was placed on identifying the ammonia release rates that elicit maximum fly responses.