Identification of two female cypress bark beetle pheromone components and evaluation of their activity in the laboratory and the field

Abstract

The cypress bark beetle, Phloeosinus aubei Perris (Coleoptera: Curculionidae, Scolytinae), is of increased concern in the market of scale-leafed conifers (Cupressaceae), across a wide range of its expansion area in Europe. Surprisingly, its pheromonal communication has only scarcely been studied no specific trap-based monitoring system is available for detection of the adults flight. In order to reveal the pheromonal communication channel, hindgut extracts of unmated females were analyzed by gas chromatography coupled to an electroantennographic detector (GC-EAD), using male antennae. Structure elucidation of antennally active components were performed by gas chromatography coupled to mass spectrometry (GC/MS). Synthetic samples of identified components were tested separately by EAG. Attraction to selected mixtures were compared by a 4-arm olfactometer, followed by field trapping tests. α-Pinene and myrtenol, as antennaly active components were identified from gut extracts. Each of these compounds, as well as their mixture attracted both males and females in significant numbers, in olfactometer tests. A 5:1 mixture of these compounds caught significantly more adults (both males and females), than unbaited control, in multifunnel traps. Preliminary experiences of stimulating pheromone production by injecting juvenile hormone (JHIII), and possible involvement of acoustic communication are discussed.