Comparative studies of predation among feral, commercially-purchased, and laboratory-reared predators

ISSN： 1386-6141

Source： BioControl, Vol.54, Iss.3, 2009-06, pp. : 351-361

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

The predatory activities of commercially-purchased adult Hippodamia convergens Guérin-Méneville and two laboratory-reared strains of adult 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 silverleaf whitefly, Bemisia argentifolii Bellows & Perring adults or eggs of pink bollworm, Pectinophora gossypiella (Saunders). Commercially-purchased H. convergens devoured more pink bollworm eggs and at a faster rate than the feral H. convergens. In contrast, feral H. convergens consumed more adult whiteflies and at a faster rate than commercial H. convergens. In multiple feeding choice tests, two distinctly different laboratory-reared strains and feral G. punctipes were provided a cotton leaf disk containing copious amounts of silverleaf whitefly eggs, nymphs, and adults. Virtually no predation was observed on whitefly eggs, but both laboratory strains of G. punctipes fed on more whitefly nymphs and adults than the feral G. punctipes. Moreover, both of the laboratory strains had a significantly faster feeding rate on adult whiteflies and spent significantly less time feeding on plant tissue than the feral strain. These results suggest that the augmentative biological control candidates retained their ability to prey on these selected prey items, even after being displaced from their overwintering site (H. convergens) or being reared in captivity (G. punctipes) for over 40 generations.