Author
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Submitted to: BioControl
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/19/2008 Publication Date: 5/20/2009 Citation: Hagler, J 2009. Comparative Studies of Predation Among Feral, Commercially-Purchased, and Laboratory-Reared Predators. Biocontrol. 54:351-361 Interpretive Summary: The predatory activities of commercially-purchased lady beetles and two laboratory-reared strains of big-eyed bugs were compared with their feral counterparts. In feeding tests, commercially-purchased and feral beetles were provided large quantities of sweetpotato whitefly adults or pink bollworm eggs. Commercially-purchased beetles devoured more pink bollworm eggs at a faster rate; however, feral beetles devoured more adult whiteflies at a faster rate. In another series of feeding tests, two laboratory-reared strains and feral big-eyed bug predators were provided a cotton leaf disk containing copious amounts of sweetpotato whitefly eggs, nymphs, and adults. Virtually no predation was observed on whitefly eggs, but both laboratory strains of big-eyed bugs fed more often on whitefly nymphs and adults. Moreover, both of the laboratory strains had a significantly faster feeding rate on adult whiteflies and spent significantly less time feeding on plant tissue. These results suggest that these augmentative biological control candidates retained their ability to prey on these selected prey items, even after being displaced from their overwintering site or being reared in captivity for over 40 generations. Technical Abstract: The predatory activities of commercially-purchased Hippodamia convergens Guèrin-Mèneville and two laboratory-reared strains of Geocoris punctipes (Say) were compared with their feral counterparts. In single prey choice feeding tests, commercially-purchased and feral H. convergens were provided copious amounts of sweetpotato whitefly, Bemisia argentifolli Bellows & Perring, adults or eggs of pink bollworm, Pectinophora gossypiella (Saunders). Commercially-purchased H. convergens devoured more pink bollworm eggs at a faster rate; however, feral H. convergens consumed more adult whiteflies at a faster rate. In multiple feeding choice tests, two laboratory-reared strains and feral G. punctipes were provided a cotton leaf disk containing copious amounts of sweetpotato whitefly eggs, nymphs, and adults. Virtually no predation was observed on whitefly eggs, but both laboratory strains of G. punctipes fed more often on whitefly nymphs and adults. Moreover, both of the laboratory strains had a significantly faster feeding rate on adult whiteflies and spent significantly less time feeding on plant tissue. These results suggest that these augmentative biological control candidates retained their ability to prey on these selected prey items, even after being displaced from their overwintering site or being reared in captivity for over 40 generations. |
