Enantiospecific Attraction of Lygus Lineolaris Palisot De Beauvois (Hemiptera: Miridae) to a Ubiquitous Floral Volatile in the Field

Abstract

Abstract Herbivorous insects utilize olfactory and visual cues to orient on suitable host plants, and such cues can be employed to facilitate insect monitoring. Lygus lineolaris Palisot de Beauvois is a polyphagous pest throughout North America. Monitoring this pest as it moves between crop and non-crop hosts remains challenging and a lack of effective monitoring tools complicates management of this insect. In this study, we examined the electrophysiological and behavioral responses of L. lineolaris to the volatile emissions of two crop hosts: Medicago sativa and Fragaria ananassa. Gas chromatography with electroantennographic detection was applied to identify antennally active compounds in headspace extracts of flowering host plants, before responses to individual compounds were examined in the field. Five compounds consistently elicited antennal depolarizations in adult L. lineolaris and, of these, (±)-linalool increased female L. lineolaris capture rate in the field. Subsequent experiments examined the influence of visual cues and stereochemistry on capture rate, revealing that lures containing (±)-linalool and (S)-(+)-linalool significantly increased female L. lineolaris capture rates compared to traps baited with (R)-(-)-linalool and controls, indicating that L. lineolaris is attracted to (S)-(+)-linalool. While lures increased capture on red traps, this was not the case for white traps, emphasizing the importance of visual cues in L. lineolaris monitoring. This study demonstrates that L. lineolaris is attracted to (S)-(+)-linalool in the field, and that attraction depends on trap color. This knowledge is expected to improve L. lineolaris monitoring in agricultural systems.