Location: Subtropical Horticulture Research
Title: Electroantennogram and behavioral responses of Anastrepha suspensa (Diptera: Tephritidae) to putrescine and ammonium bicarbonate lures Authors
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 5, 2009
Publication Date: August 6, 2009
Citation: Kendra, P.E., Montgomery, W.S., Epsky, N.D., Heath, R.R. 2009. Electroantennogram and behavioral responses of Anastrepha suspensa (Diptera: Tephritidae) to putrescine and ammonium bicarbonate lures. Environmental Entomology. 38(4): 1259-1266. Interpretive Summary: Improved trapping systems are needed for Anastrepha fruit flies, a group of serious economic pests of tropical and subtropical fruit crops. Currently, the best lures are multi-component blends that emit ammonia and putrescine – two chemicals thought to function as protein feeding cues that typically result in capture of more females. To better understand the physiological basis underlying attraction to these lures, scientists at the USDA-ARS, Subtropical Horticulture Research Station (Miami, FL) used electroantennography (EAG) to measure olfactory response of the Caribbean fruit fly (A. suspensa) to commercial lures of ammonium bicarbonate (AB) and putrescine (Pu). EAG response to AB was equivalent for both sexes, but female response was greater than male response to Pu and to a combination of AB plus Pu. Additional tests conducted with females revealed that antennal sensitivity to both lures varied depending upon maturity status. Peak response to AB was observed in sexually immature females; peak response to Pu occurred in mature females. The results suggest that separate antennal receptors are involved in detection of these two chemicals, and that the Pu component is primarily responsible for the female-biased attraction. This study is part of an ongoing program to optimize monitoring programs for use by action agencies for early detection of invasive fruit fly pests.
Technical Abstract: At present, the most effective synthetic lures for pest Anastrepha fruit flies are multi-component blends that include an ammonia-emitting substrate and the diamine synergist, putrescine (1,4-diaminobutane). Both chemicals are regarded as protein-feeding cues which result in female-biased attraction. Using electroantennography (EAG), this study quantified antennal response of the Caribbean fruit fly, Anastrepha suspensa (Loew), to vapors released from commercial lure formulations of ammonium bicarbonate and putrescine. Over a range of doses tested, EAG response to ammonium bicarbonate was equivalent for both sexes, but female response was significantly greater than male response to putrescine and to a 1:1 mixture of ammonium bicarbonate and putrescine. Amplitude of EAG response to the mixture was approximately equal to the summation of responses to the individual substrates. Using a fixed dose of substrate, EAG measurements from females 1-14 d old indicated that antennal sensitivity to both lures varied according to physiological state of the fly. Peak response to ammonium bicarbonate was observed in immature females with ovaries actively undergoing vitellogenesis, deposition of yolk proteins. Maximal antennal response to putrescine was recorded from sexually mature females. Results suggest that separate olfactory receptors are involved in detection of these two semiochemicals, and that the putrescine component is primarily responsible for the female-biased attraction.