International trade of coffee from the great lakes region of Africa is threatened by the coffee stink bug, Antestiopsis thunbergii and its association with poor quality liquor, often called the “potato taste defect”. Previous studies have reported that immature coffee berries are strongly preferred by the pest unlike other coffee parts in the field. To test whether olfactory cues mediate the coffee bug's host selection process, behavioral and electrophysiological assays were conducted using headspace volatiles from coffee berries at two different stages of maturity. Additionally, coupled gas chromatography/mass spectrometry (GC/MS) was used to analyse the chemical composition of the volatiles emitted by the two coffee berry stages. In behavioural assays, whereas volatiles of immature berries attracted the coffee bug, volatiles of mature berries repelled it. Various chemical groups including; aldehydes, esters, hydrocarbons and terpenes which contribute to the divergent behavior of A. thunbergii towards coffee berries of different maturity stages and their possible use in pest management will be discussed. (Texte intégral)