Identification of key plant-host volatiles affecting behavior of brown marmorated stink bug - Halyomorpha halys (Hemiptera: Pentatomidae) on commercial hazelnuts

Brown Marmorated Stink Bug (BMSB), Halyomorpha halys Stål (Hemiptera: Pentatomidae), was accidentally introduced to the United States in the mid of 90’s. Halyomorpha halys is of increased in economic importance as an agricultural pest due to its extensive direct and indirect damage reported to over 170 plant. Hazelnut (Corylus avellana) is both a food and reproductive host for developing H. halys populations. This work is focused on identifying plant-produced organic volatiles as possible sources of attraction. Plants, under certain circumstances express specific VOCs (volatile organic compounds) that can potentially affect the presence of phytophagous pests. The activation of attraction/repellency mechanisms and physiological-behavioral responses of BMSB to these plant-based volatiles have not been adequately described for BMSB. For this reason, the goals of our BMSB work on hazelnut were: 1) evaluation of cultivar preference, 2) characterization of husk and hair structures in relation to damage location 3) identification of antennal physiological response to active VOCs with EAG-GC and 4) observation of behavioral response to VOCs at different concentrations. BMSB showed a clear preference towards a numbered Turkish hazelnut selection. Hazelnut structural components such as husk and hairiness had a minimal impact on H. halys feeding pressure. A high number of active VOCs was extracted and characterized with mass-spectrometry analysis. Halyomorpha halys exhibited antennal physiological responses for three key tested compounds as indicated by GC-EAD trials. Behavioral studies with a Y-tube olfactometer showed male H. halys attraction toward two specific compounds, while females showed repellency for one in particular.