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; however, no evaluations have been done on the effectiveness of artificial diet reared parasites in the field. This research provides a comparison of searching capacity and dispersal ability among C. grandis reared in artificial diet and those reared on boll weevils. These have a similar searching capacity, but C. grandis reared in artificial diet had a reduced dispersal ability compared to wasps reared in the boll weevil. Nevertheless, this experiment shows that C. grandis reared on artificial diet are as effective at parasitizing boll weevils in the field as those reared on the boll weevil. Increasing the number of release points without increasing the number of wasps released per acre should compensate for their reduced mobility.
The movement, searching capacity, and survival under field conditions of in vitro and in vivo reared Catolaccus grandis (Burks) females were compared in Ricardo and Lyford, Texas. Dispersal ability and searching capacity was not significantly different within the 30-m radius among parasitoid females reared by the two different methods. However, a significantly higher proportion of stations with parasitism was recorded from in vivo-reared C. grandis at a 60 m radius. These results indicate that in vitro-reared C. grandis have a significantly lower dispersal ability, but, their searching capacity is not significantly affected.