Biocontrol introduction
Target pest: Tetranychus urticae (Acariformes: Tetranychidae), two-spotted spider mite
Agent introduced: Galendromus occidentalis (Parasitiformes: Phytoseiidae) = Metaseiulus occidentalis, Typhlodromus occidentalis
Imported:
1976
Import source:
North America via Australia
Import notes:
Cameron et al. (1989) - an organophosphorus-resistant strain of G. occidentalis was imported into New Zealand (as Typhlodromus occidentalis) from Australia in 1976, following its successful introduction into that country from North America in 1972. It was initially reared in quarantine and later laboratory-reared in Auckland. This species was already present in New Zealand prior to the release of the organophosphorus-resistant strain.
Released:
1976
Release details:
Cameron et al. (1989) - the organophosphorus-resistant strain of G. occidentalis was released at Nelson, Waimate, Central Otago and Canterbury (Loburn and Lincoln) in the South Island, and at Hastings, Hawke’s Bay in the North Island.
Establishment:
Cameron et al. (1989) - the organophosphorus-resistant strain of G. occidentalis became established in Central Otago, Canterbury and at Hope, Nelson. In Canterbury and Central Otago this strain has persisted in orchards at very low levels.
Impacts on target:
Cameron et al. (1989) - initial control of T. urticae on apple trees at Hope, Nelson was encouraging. However, although within-season control was obtained on release trees following release, G. occidentalis has not achieved the same degree of successful control of T. urticae and other phytophagous pest mites in New Zealand as that reported in Australia and North America. In Canterbury, populations of G. occidentalis established in berryfruit crops have now been largely replaced by another introduced predatory mite biocontrol agent, Phytoseiulus persimilis.
References
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.
