Target pest: Coleophora spissicornis (Lepidoptera: Coleophoridae), banded clover casebearer
Agent introduced: Diadegma majalis (Hymenoptera: Ichneumonidae) = Diadegma majale
1952 near MontmĂ©dy, France; 1968 Avignon, France via DelĂ©mont, Switzerland
Cameron et al. (1989) - Diadegma majalis was imported as parasitised Coleophora spp. host larvae; either C. frischella collected from Avignon, France (and reared in DelĂ©mont, Switzerland prior to shipment) or C. trifolii from near MontmĂ©dy, France. An August 1952 importation of C. trifolii had a total parasitism rate estimated at 60-70%, though rates for individual parasitoid species were not recorded. Imported host larvae were held in cool storage until locally-sourced hosts became available. Parasitoid emergence continued over summer and parasitised hosts were released in March 1953. Diadegma majalis was also reared from three 1968 importations of C. frischella larvae, from which 12 females and 31 males emerged. An unsuccessful attempt was made to rear these in the laboratory on Coleophora spp. of various stages.
Cameron et al. (1989) - in March 1953, several hundred parasitised Coleophora spp. [apparently a mix of locally-collected Coleophora spp. and unemerged C. trifolii from the August 1952 importation] containing D. majalis (as well as other parasitoids) were released, probably in Nelson.
Cameron et al. (1989) - there have been no recoveries of D. majalis.
Cameron PJ, Hill RL, Bain J, Thomas WP (1989). A Review of Biological Control of Invertebrate Pests and Weeds in New Zealand 1874-1987. Technical Communication No 10. CAB International Institute of Biological Control. DSIR Entomology Division. 424p.