Evaluation of Catolaccus grandis (Burks) (Hym., Pteromalidae) as a biological control agent against cotton boll weevil

An evaluation of augmentative releases carried out at the Agreste site of the state of Paraiba, Brazil, provided significant insight into the ecology and potential impact of Catolaccus grandis (Burks) against the boll weevil, Anthonomus grandis Boheman in that cotton agroecosystem. The rate of increase in density of C. grandis was higher than the boll weevil. Catolaccus grandis showed ability to effectively search and reproduce within the release environment and revealed pronounced host and habitat preferences. Parasitism by C. grandis was largely confined to third instar weevil larvae, the majority of which (86.9%) occurred in abcised cotton squares. Catolaccus grandis inflicted significant mortality on third instar weevil larvae in the plot resulting in a significant level of suppression. The net effect was a higher boll weevil mortality in the release plot in comparison with the control. The use of augmentative releases of C. grandis has a very high potential for supplementing and enhancing available technology for suppressing boll weevil populations in the Agreste Paraiba.