ARS | Publication request: LABORATORY EVALUATION OF FIRST, SECOND, FIFTH AND TENTH IN VITRO-REARED GENERATION OF CATOLACCUS GRANDIS

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: November 8, 1995
Publication Date: N/A

Interpretive Summary: The introduced natural enemy of the boll weevil, Catolaccus grandis, has been tested with success against infestations of this pest in South Texas during the past four years. However, the high costs of mass propagating this beneficial wasp limits its commercial application. One important step has been the development of an artificial diet to rear this wasp without the need of the boll weevil. This research provides evaluations of biological characteristics of C. grandis reared in artificial diet for up to ten generations. Results indicate that wasps reared in artificial diet for five generations are as healthy as those reared on boll weevils. Rearing C. grandis in artificial diet for ten generations reduces significantly its fecundity. However, five generations of this wasp are sufficient to produce all the beneficial insects needed to control the boll weevil within a cotton growing season. These promising results show that it is possible to commercially produce C. grandis in artificial diet without the need of boll weevil rearing, at least during a single cotton producing season.

Technical Abstract: The biological characteristics of the ectoparasitoid Catolaccus grandis (Burks) were evaluated after 1, 2, 5, and 10 generations of in vitro- rearing and compared to parasitoids reared in boll weevil (Anthonomus grandis Boheman) larvae. The weight of female pupae was not significantly affected after 10 successive generations reared on artificial diet. Fecundity of in vitro F2 females was significantly higher than that of in vitro F1 females. Fecundity of C. grandis was not significantly reduced after 5 generations of in vitro-rearing. However, the in vitro F10 showed a significantly lower fecundity than all other in vitro generations. Females reared on boll weevil larvae had a higher pupal weight and fecundity than females reared in vitro, but in vitro-reared females showed a significantly higher survival during the most actively reproductive ages.