4d.Progress report.
This report serves to document research conducted under a collaborative agreement between the USDA-ARS-South American Biological Control Laboratory and the Plant Protection Research Institute (PPRI), Pretoria, South Africa, started on 11/01/2004. Some species of mesquite are considered invasive weeds in South Africa. In an attempt to limit the reproductive potential of these plants, while preserving their beneficial attributes, biological control in South Africa has been restricted to the use of seed-feeding agents. The PPRI has focused the attention on insects attacking unripened pods. The main objective of this research project was to discover and study host-specific biocontrol agents that occur in Argentina, with the potential to destroy the seeds, pods, flowers, and the flower buds of noxious mesquite species in South Africa. The main candidate, prioritized for further studies, was a new species of a seed-feeding weevil that lays eggs on immature pods of mesquite species.

Major accomplishments: The weevil, reported previously as a new species of Apion, was recently identified as a new species of Coelocephalapion. Field surveys and biological studies were conducted including: duration of immature stages, oviposition preference and damage on pods and seeds of a mesquite species in Northwestern Argentina.