Laboratory evaluation of natural and synthetic aromatic compounds as potential attractants for male mediterranean fruit fly, ceratitis capitata

Authors: Tabanca, Nurhayat; MASI, MARCO - University Of Naples; Epsky, Nancy; NOCERA, PAOLA - University Of Naples; CIMMINO, ALESIO - University Of Naples; Kendra, Paul; NIOGRET, JEROME - Niogret Ecology Consulting; EVIDENTE, ANTONIO - University Of Naples

Submitted to: Molecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/27/2019
Publication Date: 6/29/2019
Citation: Tabanca, N., Masi, M., Epsky, N.D., Nocera, P., Cimmino, A., Kendra, P.E., Niogret, J., Evidente, A. 2019. Laboratory evaluation of natural and synthetic aromatic compounds as potential attractants for male mediterranean fruit fly, ceratitis capitata. Molecules. 24(13):2409. https://doi.org/10.3390/molecules24132409.
DOI: https://doi.org/10.3390/molecules24132409

Interpretive Summary: The Mediterranean fruit fly, or medfly (Ceratitis capitata), is one of the most serious pests of fruits and vegetables worldwide due to direct damage to crops and high costs incurred with control and eradication efforts. Current management strategies utilize a variety of attractants, including protein baits and food-based synthetic lures for females, and the synthetic parapheromone trimedlure for detection of males. To provide increased understanding of the chemical structures underlying attraction of medfly, scientists from the USDA-ARS (Miami, FL), in collaboration with chemists at the University of Naples (Napoli, Italy), investigated a series of 29 structurally-related phenolic compounds that differed in functional groups. A combination of laboratory bioassays and electroantennographic analyses were conducted to quantify behavioural and olfactory responses, respectively, and four potential new attractants were identified for males. These active compounds contained an allyl reside and specific functional groups in ortho- and/or para- position on the aromatic ring. This study revealed some key structural features responsible for attraction, information that will benefit future researchers in the development of improved lures for Mediterranean fruit fly.

Technical Abstract: Ceratitis capitata, the Mediterranean fruit fly, is one of the most serious agricultural pests worldwide, responsible for significant reduction in fruit and vegetable yields. Eradication is expensive and often not feasible. Current control methods include the application of conventional insecticides, leading to pesticide resistance and unwanted environmental effects. The aim of this study was to identify potential new attractants for incorporation into more environmentally sound management programs for C. capitata. In initial no-choice bioassays, a series of naturally occurring plant and fungal aromatic compounds and their related analogs were screened, identifying phenyllactic acid (7), estragole (24), o-eugenol (21), and 2-allylphenol (23) as promising attractants for male C. capitata. Subsequent no-choice tests evaluated five hemisynthetic derivatives prepared from 2-allylphenol, but none of these were as attractive as 2-allylphenol. In binary choice bioassays with the four most attractive compounds, males were more attracted to o-eugenol (21) than to estragole (24), 2-allylphenol (23), or phenyllactic acid (7). In addition, electroantennography (EAG) was used to quantify antennal olfactory responses to the individual compounds (1-29), and the strongest EAG responses were elicited by 1-allyl-4-(trifluoromethyl)benzene (11), estragole (24), 4-allyltoluene (14), trans-anethole (9), o-eugenol (21), and 2-allylphenol (23). The compounds evaluated in the current investigation provide insight into chemical structure-function relationships and help direct future efforts in development of improved attractants for detection and control of invasive C. capitata.