Visual Cues Enhance the Response of Lygus hesperus (Heteroptera: Miridae) to Volatiles from Host Plants

• Published in: Environmental entomology 2005-12, Vol.34 (6), p.1524-1533
• Main Authors: Blackmer, J. L, Cañas, L. A
• Format: Article
• Language: English
• Subjects: additive response; alfalfa; Animal ethology; BEHAVIOR; Biological and medical sciences; conspecific odors; Control; developmental stages; Fundamental and applied biological sciences. Psychology; gender differences; host plants; host seeking; Integrated pest control; light-emitting diode; Lygus hesperus; Medicago sativa; olfactometry; olfactory cues; orientation behavior; Phytopathology. Animal pests. Plant and forest protection; plant odors; plant volatiles; Protozoa. Invertebrata; Protozoa. Invertebrates; Psychology. Psychoanalysis. Psychiatry; smell; synergistic response; vision; volatile compounds; western tarnished plant bug
• ISSN: 0046-225X; 1938-2936; 0046-225X
• DOI: 10.1603/0046-225X-34.6.1524

Studies were conducted to examine the behavioral response of fifth-instar and adult Lygus hesperus Knight (Heteroptera: Miridae) to odors associated with a host plant (alfalfa) when presented singly or in combination with a visual plant cue (530 nm, green light-emitting diode [LED]). Bioassays were conducted in a modified Y-tube olfactometer, where incoming air was filtered and humidified before passing through chambers that held plant/conspecific treatments. A LED, placed behind an organdy screen at the end of one arm of the Y-tube, simulated a visual plant cue. In agreement with our previous findings, fifth-instar and adult female L. hesperus were attracted to plant/conspecific odor combinations, but adult males were not. Independently, the LED also was attractive to immature and adult female L. hesperus, and for all life stages, a much larger percentage of the bugs walked to the extreme end of the Y-tube when the visual cue was present. When visual and volatile cues were presented simultaneously, responses by both immature and adult (male and female) L. hesperus were significantly enhanced. Plant/conspecific treatments that had been marginally acceptable when only volatile stimuli were available showed the greatest enhancement in response with the addition of the visual cue. Presentation of visual and volatile cues together led to a mean increase in the percentage of bugs that walked to the extreme end of the Y-tube (nymphs, 36.6%; females, 23.4%; males, 26.1%). Results are discussed in terms of stage-specific responses and how these behavioral differences will likely play a role in developing effective trapping and monitoring systems for this important pest.