Electrophysiological Responses of the Mediterranean Fruit Fly, Ceratitis capitata, to the Cera Trap® Lure: Exploring Released Antennally-Active Compounds

The Mediterranean fruit fly (medfly), Ceratitis capitata, is a worldwide pest of agriculture able to use olfactory cues to locate habitat, food sources, mates and oviposition sites. The sensitivity of medfly olfaction has been exploited to develop olfactory-based attractants that are currently important tools for detection, control and eradication of its populations. Among these is Cera Trap® (BIOIBERICA, S.A.U.), a cost-effective bait. Here we used coupled gas chromatography/electroantennographic detection (GC-EAD) and GC/mass spectrometry (GC-MS) approaches to characterize the medfly antennally-active compounds released by this lure. We identified GC peaks corresponding to chemicals belonging to six different classes including heterocyclic aromatic compounds, aliphatic alcohols, aldehydes, esters, sesquiterpene hydrocarbons, and aromatic alcohols. We tested ten potential candidate volatiles belonging to these classes and predicted to be emitted by the lure and found that they were eliciting electroantennographic responses in medfly adults. These results will help in unravelling the physiological mechanisms of odor perception in both sexes, especially in relation to Cera Trap® attractant activity, which in the field has been shown to be female-specific. These findings and their developments will ultimately expand the toolbox for medfly control in the field.