Biocontrol introduction
Target pest: Acyrthosiphon pisum (Hemiptera: Aphididae), pea aphid
Agent introduced: Aphidius smithi (Hymenoptera: Braconidae)
Imported:
1977
Import source:
Afghanistan, California, Israel and Iran, all via USA.
Import notes:
Cameron et al. (1989) - four strains (Afghanistan, California, Israel, Iran) were received from University of California, Riverside, USA in December 1977, but only three were cultured (Iran was not), and two of these (Afghanistan and California) as a mixed strain.
Released:
1977
Release details:
Cameron et al. (1989), Cameron & Walker (1989) - releases were made between 1977 and 1980 and numbers released by strain were as follows: Afghanistan 290; California 105; Afghanistan x California 34,920; Israel 1,910; Iran 135. Releases were initially widespread (Northland, Auckland, Taupo, Wanganui in the North Island; Mid Canterbury in the South Island) with later releases in 1979-80 concentrated in the Helensville (Auckland) and Wairakei (Taupo) areas. All major releases were in Auckland area. Parasitoids were released as mummies harvested from plants, or as mummies and parasitised aphids on potted plants. Usually, harvested mummies were released into field cages which were removed after emergence of adult parasitoids, but occasionally they were scattered over lucerne at the release site.
Establishment:
Cameron et al. (1989) - the only confirmed recoveries were from field cages. Difficult to distinguish from A. eadyi but is considered not to be established in New Zealand.
Cameron & Walker (1989) - laboratory trials indicate a very low development threshold (estimated at 2.4°C) for A. smithi, suggesting that laboratory culture may have produced a strain which would be inappropriately active before its host at the start of the season when conditions are cool. This may have contributed to the failure of A. smithi to establish.
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.
Cameron PJ, Walker GP (1989). Release and establishment of Aphidius spp. (Hymenoptera: Aphidiidae), parasitoids of pea aphid and blue green aphid in New Zealand. New Zealand Journal of Agricultural Research 32: 281-290 https://doi.org/10.1080/00288233.1989.10423463
