Classical biological control of weeds with Curculionidae.

Abstract

Abstract The intentional use of insects to control weeds has been in practice for more than 150 years. Historically, species from the orders Lepidoptera and Coleoptera have shown the greatest success. Among the Coleoptera, the weevils (family Curculionidae) have played an integral role in the suppression of more than 50% of targeted weed programmes in various regions of the world. Notable successes using Curculionidae are in the control of waterhyacinth, Australian Acacia spp. and several thistle species. Published records indicate that of the 67 weed species targeted for control with Curculionidae worldwide, most are terrestrial-herbaceous weeds (65.7%). Curculionidae used for most of the targeted terrestrial-herbaceous ( n =44) and aquatic/semi-aquatic weeds ( n =6) are in North America, while the majority of the terrestrial-arborescent weeds ( n =17) are in Africa. Of the 75 species of Curculionidae used to control these weeds worldwide, 34 are in North America. Success, as defined by the establishment of a biological control agent that has a detrimental impact on the target weed, is dependent on the number of programmes implemented and the resources for follow-through. This review provides insight into the successful establishment of some selected weevil species and their impact on their target weeds.