Target pest: Phthorimaea operculella (Lepidoptera: Gelechiidae), potato tuber moth
Agent introduced: Bracon gelechiae (Hymenoptera: Braconidae) = Microbracon gelechiae
North America via Australia (1949), Northern Argentina and southern Brazil via India (1969-70)
Cameron et al. (1989) - in March 1949 a permit was obtained to import one shipment of several P. opercullela parasitoids, including B. gelechiae, from Australia, for release after laboratory emergence of adults. The numbers imported were not recorded. Between November 1969 and April 1970 there were eight shipments of B. gelechiae from the Commonwealth Institute of Biological Control station in India to Nelson, New Zealand; most were directly released although a small number were retained at Nelson for laboratory culture. A limited number were bred and a few released there before the laboratory host population became infected with a granulosis virus and the rearing programme was terminated. The B. gelechiae material imported from Australia in 1949 had originally been sourced from North America. The material imported in 1969-70 had been originally sourced from northern Argentina and southern Brazil in 1963-64 and cultured at the Californian Station of CIBC; when this station closed, the colony was transferred to the Indian Station of CIBC, from where the shipments were made to New Zealand.
Cameron et al. (1989) â€“ unknown numbers of adult B. gelechiae were [seemingly] released at Nelson from the 1949 importation. Approximate numbers released from the 1969-70 importations were 265 at Lincoln, Canterbury and Oamaru, North Otago, South Island (specific numbers at each site was not clear in the records), and 1,400 at Nelson, South Island.
Cameron et al. (1989) - sporadic examination of potato tubers and foliage at Oamaru, North Otago and Lincoln, Canterbury for P. opercullela parasitoids was undertaken between mid-1967 and late-1973; there are no records of B. gelechiae being detected. The B. gelechiae released at Nelson in 1969-70 were known to have bred in the field for at least one generation that season, but a subsequent survey showed it had not established there on P. opercullela.
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.