Target pest: Calliphora stygia (Diptera: Calliphoridae), brown blowfly
Agent introduced: Nasonia vitripennis (Hymenoptera: Pteromalidae)
Imported: pre 1922, 1922
Import source: Australia
Released: pre 1922, 1922
Release details: Cameron et al. (1989) - released in 'large numbers' at Timaru, North Canterbury, Blenheim, Hawke's Bay and Whangarei in 1922. This official liberation was preceded by a private release in Blenheim before 1922 (no date given).
Establishment: Cameron et al. (1989) - a 1930 publication noted that the blowfly parasitoid Tachinaephagus zealandicus occurred in greater numbers than N. vitripennis [indicating N.vitripennis had established, though no information is given about distribution].
Impacts on target: Early (1984) - nothing is known of the effectiveness of introduced parasitoids in reducing either blowfly populations or flystrike on sheep. Cameron et al. (1989) - as flystrike continues to be a significant problem in New Zealand the overall effects of parasitoids have presumably been minimal. A 1927 publication noted there was no perceived effect of N. vitripennis upon blowfly numbers. The reason given for its lack of success was that it is a pupal parasitoid and cannot locate pupae buried underground.
Impacts on non-targets: Early (1984) - N. vitripennis attacks the common house fly (Musca domestica) as well as "European [Calliphora vicina], small blue [it is uncertain which species this refers to; perhaps Calliphora vomitoria], New Zealand blue [Calliphora quadrimaculata, a New Zealand native, an occasional flystrike blowfly], brown [Calliphora stygia, a target species], green [Lucilia sericata, a target species], and hairy maggot [Chrysomya rufifacies, a target species] blow flies." Cameron et al. (1989) - N. vitripennis was considered as a biological control for flystrike blowflies despite having been first reared from the house fly M. domestica in USA as early as 1908. Hosts other than the target hosts in New Zealand include C. vicina and C. quadrimaculata.
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.
Early JW. (1984). Parasites and predators. Chapter 16, New Zealand Pest and Beneficial Insects. Ed. R.R. Scott. Lincoln University College of Agriculture, 1984. 373 pp.