A description of the commercial rearing and distribution of Microctonus hyperodae (Hymenoptera: Braconidae) for biological control of Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae)

A classical biological control program against Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae) in New Zealand commenced in 1989 with the importation of the braconid endoparasitoid Microctonus hyperodae Loan. In 1991, approximately 99,000 parasitized weevils were released at eight sites in the North and South Islands. Parasitoid establishment occurred at all sites and rates of parasitism suggested that the biological control agent would be successful. Research, which indicated that M. hyperodae dispersed at about 1.5–3.0 km yr−1, made multiple releases worthwhile. From 1993 to 1998 releases were made on a commercial basis. This approach, in part, was driven by a government requirement that, where possible, science should operate on a commercial/cost recovery basis. Clients included individual farmers and territorial authorities. The creation and development of a successful commercial program to sell the parasitoid are reviewed along with discussion of results and problems encountered. At the conclusion of the program about 613,000 parasitized weevils had been sold and released at 112 locations within New Zealand.