Male-Produced (−)-δ-Heptalactone, Pheromone of Fruit Fly <i>Rhagoletis batava</i> (Diptera: Tephritidae), a Sea Buckthorn Berries Pest

• Main Authors: Vincas Būda, Laima Blažytė-Čereškienė, Sandra Radžiutė, Violeta Apšegaitė, Patrick Stamm, Stefan Schulz, Dominykas Aleknavičius, Raimondas Mozūraitis
• Format: Article
• Language: English
• Published: MDPI AG 2020-02-01
• Series: Insects
• Subjects: <i>rhagoletis batava</i>; pheromone identification; synthesis; bioassay; field trapping; spme; gc-ead; gc-ms
• Online Access: https://www.mdpi.com/2075-4450/11/2/138

The plantation area of sea buckthorn (<i>Hippophae rhamnoides</i> L.) is expanding in many European countries due to increasing demand for berries, thus creating suitable conditions for the rapid expansion of the fruit fly <i>Rhagoletis batava</i>, a pest of economic importance. To decrease insecticide use, effective means for pest population monitoring are required, including the use of pheromones. Male fruit flies emit (-)-&#948;-heptalactone as revealed by gas chromatography-mass spectrometry analyses of samples obtained using headspace methods. The two enantiomers of &#948;-heptalactone were synthesized using enantioselective synthesis. A gas chromatography-electroantennographic detection analysis of both stereoisomers revealed that only (-)-&#948;-heptalactone elicited electrophysiological responses, whereas no signal was registered to (+)-&#948;-heptalactone in fruit flies of either sex. In the field assay, traps baited with (-)-&#948;-heptalactone caught significantly more fruit flies compared with the unbaited traps. Our results are the first to demonstrate the efficacy of (-)-&#948;-heptalactone as a bait for trapping <i>R. batava</i>. As a behaviorally attractive compound to <i>R. batava</i> fruit flies of both sexes, (-)-&#948;-heptalactone is attributed to aggregation pheromones. This is the first report of an aggregation pheromone within the genus <i>Rhagoletis</i>.