Location: Tropical Crops and Germplasm ResearchTitle: Antennal responses of West Indian and Caribbean fruit flies (Diptera: Tephritidae) to ammonium bicarbonate and putrescine lures) Author
Submitted to: Florida Entomologist
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/27/2011
Publication Date: 3/1/2012
Citation: Jenkins, D.A., Kendra, P.E., Epsky, N.D., Montgomery, W.S., Heath, R.R., Jenkins, D.M., Goenaga, R.J. 2012. Antennal responses of West Indian and Caribbean fruit flies (Diptera: Tephritidae) to ammonium bicarbonate and putrescine lures. Florida Entomologist. 95(1):28-34. Interpretive Summary: The family of Tephritid fruit flies includes many important pest species. Countries may restrict the import of fruits from countries where these flies are present. As such, there is a premium set on tools that efficiently monitor populations of these species or detect the arrival of exotic species. A key tool is the plastic MultiLure trap baited with ammonium acetate and putrescine. These lures attract a wide variety of species and thus are used in different regions to monitor and detect populations of economically important fruit flies. We used a device known as an electroantennagram to record the antennal responses of wild fruit flies from Puerto Rico to different doses of the compounds used to attract them, namely, ammonia and putrescine. These responses can be quantified and used as a proxy for the attractiveness of a compound. We found that one species, Anastrepha obliqua, responded in a stronger manner to the lures ammonium bicarbonate and ammonium bicarbonate with putrescine than the other species found in Puerto Rico, A. suspensa. Our results with A. suspensa were broadly similar to those obtained by an earlier study on a Florida population of A. suspensa. Our results indicate that there are differences in the magnitude of response to these baits between species and that these differences may reflect differences in trap capture in different regions where these baits are used.
Technical Abstract: Efforts to monitor and detect tephritid fruit flies in the genus Anastrepha currently involve MultiLure traps baited with two food-based synthetic attractants; ammonium acetate and putrescine (1,4-diaminobutane). These baits are used in Central America, Florida, Texas, and the Caribbean, each region with its own group of economically important Anastrepha spp. The efficacy of these baits varies by region and by species. Antennal responses to these compounds have been tested on A. suspensa populations in Florida, but not elsewhere. This is the first report of antennal responses of Puerto Rican populations of A. obliqua and A. suspensa to the bait odors ammonium bicarbonate and putrescine. Responses to all of the volatiles (tested separately and in a mixture), as measured using electroantennagrams (EAG), were dose dependant for both species and both sexes. Although the average response to ammonium bicarbonate in combination with putrescine was always numerically higher than responses to ammonium bicarbonate alone within a species and a sex, this result was never statistically significant. Males of A. obliqua responded at lower levels than females, while males of A. suspensa responded at higher levels than females to all volatiles and volatile mixtures, but this effect was not statistically significant at any dose. Higher responses were measured for A. obliqua females than for A. suspensa females at all doses for all volatiles and all volatile mixtures and these differences were determined to be statistically significant for the two highest doses (2 ml and 4 ml) of ammonium bicarbonate and ammonium bicarbonate in combination with putrescine. Our results are broadly similar with the electrophysiological studies conducted on Florida populations of A. suspensa, but there are important differences, including the fact that the Florida study detected significantly lower responses by males than females to putrescine and ammonium bicarbonate in combination with putrescine. The implications of our results are discussed with respect to monitoring practices in different regions.