Author
Tillman, Patricia - Glynn | |
MULLINIX, JR., BENJAMIN - UNIVERSITY OF GEORGIA |
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/26/2003 Publication Date: 12/1/2003 Citation: Tillman, P.G., Mullinix, Jr., B.A. 2003. Effect of prey species on plant feeding behavior by the big-eyed bug, Geocoris punctipes (Say) (Heteroptera:Geocoridae), on cotton.. Environmental Entomology. 32(6):1399-1403. Interpretive Summary: Since Bt cotton is not highly resistant to corn earworms (CEW) and CEW have developed resistance to pyrethroids in isolated locations in the southeast, this insect pest can be a serious problem in cotton. Of the many natural enemies associated with cotton, one of the most effective predators is the big-eyed bug, but this predator also feeds on cotton plants. So, in this study, the effect of prey quality and prey size on cotton plant feeding behavior by big-eyed bug females was determined for three treatments: 1) CEW eggs (small, high quality food), 2) adult cotton aphids (low quality food), and 3) young CEW worms (large, high quality food). More plant feeding occurred when big-eyed bugs were provided less suitable prey (cotton aphids). Nevertheless, plant feeding occurred on cotton regardless of prey species or prey size even with unlimited high quality prey. Providing healthy cotton to these predators, reducing systemic insecticides sthat can harm big-eyed bugs, and providing other quality plant food could help in the conservation of these predators increasing their effectiveness as natural enemies in CEW in cotton. Technical Abstract: The effect of prey quality and prey size on cotton plant feeding behavior on cotton by Geocoris punctipes (Say) (GP) females was determined for three treatments: 1) corn earworm (CEW), Helicoverpa zea (Boddie), eggs (small high quality food), 2) adult cotton aphids, Aphis gossypii Glover (low quality food), and 3) CEW 1st instars (large high quality food). GP spent more total time per female feeding on CEW than on aphids, and more time feeding on plants when given aphids as hosts than when given CEW. Thus, more plant feeding occurred when females were provided less suitable prey (cotton aphids). Nevertheless, plant feeding occurred on cotton regardless of prey species or prey size even with unlimited high quality prey. From this feeding behavior, we can conclude that GP will feed on plants as part of their normal diet. Providing healthy cotton to these predators, reducing systemic insecticides that can harm GP, and providing other quality plant food could help in the conservation of these predators increasing their effectiveness as natural enemies of CEW in cotton. |