Electroantennogram response and attraction of Anastrepha suspensa to volatiles of various sugar sources and aged sugar solutions

Authors: GUILLEN, LARISSA - Ecology Institute; Epsky, Nancy; Kendra, Paul; Montgomery, Wayne; Gill, Micah; Allen, Carina; NIOGRET, JEROME - Mars, Inc; HEATH, BOB - Former ARS Employee

Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2016
Publication Date: 9/16/2016
Citation: Guillen, L., Epsky, N.D., Kendra, P.E., Montgomery, W.S., Gill, M.A., Allen, C.L., Niogret, J., Heath, B. 2016. Electroantennogram response and attraction of Anastrepha suspensa to volatiles of various sugar sources and aged sugar solutions. Entomologia Experimentalis et Applicata. 160(3):251-258. doi:10.1111/eea.12483.

Interpretive Summary: Tephritid fruit flies are some of the most serious economic pests of fruit crops worldwide. Traps baited with ammonia-based lures are the current standard for fruit fly monitoring, but many species, particularly in the genus Anastrepha, are not highly attracted to these lures. Identification of new attractants may provide for more effective pest detection. Scientists from the USDA-ARS Subtropical Horticulture Research Station (Miami, FL), in collaboration with the Intituto de Ecología (Veracruz, Mexico), evaluated six different types of sugar to look for potential food-based attractants. First, electroantennography (EAG) was used to determine how well the flies could detect odors emitted from sugar solutions. Then, sugars with the highest EAG responses were used in controlled lab tests to determine which ones attracted the most flies. The best results were obtained with fermented solutions of date jaggery sugar, and this sugar warrants further investigation as a source of new attractive chemicals. This information will facilitate development of improved lures for use by action agencies that monitor for pest tephritid fruit flies.

Technical Abstract: With the aim of finding new, sugar-based volatile attractants for economically important tephritid fruit fly species, we used electroantennography (EAG) to quantify olfactory responses of female Caribbean fruit fly, Anastrepha suspensa (Loew), to volatiles of six different sugars (refined white and brown cane sugar, coconut and date sugars, date jaggery and cane panela). Laboratory strain and wild flies, both sexually immature and mature, were tested for EAG response to dry crystalized sugars and 10% (w/v) aqueous solutions that had fermented in the laboratory for 0-7 days. Fermentation rates were measured by emissions of carbon dioxide. In general, wild flies exhibited higher EAG responses than laboratory flies, and immature females responded more strongly than mature females. With the exception of date jaggery and cane panela, dry sugars elicited lower EAG responses than any of the fermented solutions, and mot solutions elicited maximal EAG response after fermentation for 4 d. In both dry and aqueous presentations, date jaggery elicited the highest amplitude EAG responses (23.88 ± 1.06 %, mean ±SE) and refined white sugar the lowest (1.95 ± 0.1 %). Of the treatments evaluated, 3-6 d old solutions of date jaggery sugar gave the best overall EAG responses in wild, laboratory, immature and mature female A. suspensa. Therefore, date jaggery solutions, fermented 2 and 4 d, were evaluated for behavioral response in two-choice flight tunnel bioassays. With both mature and immature females, the 2-d old solution was more attractive than the 4-d old jaggery solution, but significantly higher numbers of mature females (70% of captures) were attracted to 2-d old jaggery solution. We discuss our results with respect to the improvement of fruit fly lures by incorporation of elements from fermented date jaggery sugar.