Submitted to: Environmental Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/25/2004
Publication Date: 6/1/2005
Citation: Kendra, P.E., Vazquez, A., Epsky, N.D., Heath, R.R. Ammonia and carbon dioxiode: quantitation and electroantennogram responses of caribbean fruit fly, anastrepha suspensa (diptera: tephritidae). 2005. Environmental Entomology. 34(3): 569-575. Interpretive Summary: Worldwide, the tephritid fruit flies make up a group of very serious agricultural pests. The Caribbean fruit fly poses a threat to tropical and subtropical fruits, and is considered a quarantine pest of citrus in Florida. As a result, much emphasis has been placed on the development of trapping systems, with a current focus on female-targeted traps baited with synthetic lures. Scientists at the Subtropical Horticulture Research Station investigated the neurophysiological basis underlying fruit fly attraction. They evaluated a commercially available lure which releases ammonia and carbon dioxide. Electroantennography technology was used to measure Caribbean fruit fly olfactory response to ammonia, carbon dioxide, and a blend of the two attractants. Ammonia elicited a much stronger response than carbon dioxide, and female flies responded more strongly than males to both ammonia and carbon dioxide. When the two were combined, the response was additive, increasing preferential attraction to females. The results were presented as a mathematical model which can be applied as a useful method for screening and comparing potential attractants. This information will aid in the development of improved lures and effective trapping systems for monitoring and controlling pest fruit flies.
Technical Abstract: Electroantennogram (EAG) recordings were made from sexually mature Caribbean fruit flies, Anastrepha suspensa (Loew), to quantitate chemoreceptive response to a commercial ammonium bicarbonate lure, as well as to measure responses to pure ammonia (NH3), pure carbon dioxide (CO2), and a blend of the two gases comparable to that released from the lure. For all compounds tested, mean female response was greater than male response. For both sexes, NH3 elicited a much stronger response than did CO2. When NH3 and CO2 were combined, either as a blend of pure gases or as the vapor emitted from the lure, the EAG response was approximately equal to the sum of the individual responses to the two compounds. This additive response indicates that two distinct olfactory receptor types are involved. Our EAG results are used to present a simple hyperbolic model for describing antennal response to single attractants. This model can be used to compare different attractants, to predict responses from specific quantities of attractants, and to determine maximum response attainable for a given stimulus.