Biocontrol introduction
Target pest: Sirex noctilio (Hymenoptera: Siricidae), sirex wood wasp
Agent introduced: Megarhyssa nortoni nortoni (Hymenoptera: Ichneumonidae)
Imported:
1962, 1963, 1964
Import source:
California, USA
Import notes:
Cameron et al. (1989) - adult M. n. nortoni were received from the California Station of the Commonwealth Institute of Biological Control in 1962 (two females), 1963 (one male, two females) and 1964 (144 males, 233 females). Oviposition in an insectary onto S. noctilio larvae occurred and the first progeny emerged in 1963. The last two consignments in 1964 were not used for colony rearing but released directly into the field. Insectary culturing for releases continued for the next six years.
Released:
1964
Release details:
Cameron et al. (1989) - two consignments of adults received in 1964 were directly released; for the following six years releases were of insectary-reared individuals, after which specimens for liberation were obtained from established populations in the field. The 1964 releases of imported individuals were at Waitangi (Northland, North Island); the first reared individuals were released at Tairua (Waikato, North Island) and the parasitoid was eventually released in 33 forests and plantations.
Establishment:
Cameron et al. (1989) - by 1988 M. n. nortoni had been recovered from 17 of the 33 forests and plantations in which it had been released and was known to have spread naturally to 23 other localities.
Impacts on target:
Cameron et al. (1989) - the presence of successfully introduced parasitoids [including M. n. nortoni], together with the accidentally introduced nematode Deladenus siricidicola [subsequently reclassified as Beddingia siricidicola] and good forest management has been effective in keeping losses caused by S. noctilio at a low level. The combined effect of the introduced parasitoids may kill over 70% of S. noctilio larvae in a particular forest.
Cameron et al. (1993) - Megarhyssa nortoni nortoni, in conjunction with Ibalia leucospoides leucospoides, Ibalia leucospoides ensiger and Rhyssa persuasoria persuasoria [see the I. l. leucospoides, I. l. ensiger and R. p. persuasoria introduction entries], is categorised as exerting “partial” control (defined as “additional control remains commonly necessary but…pest outbreaks occur less frequently”) over Sirex noctilio.
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, Hill RL, Bain J, Thomas WP (1993). Analysis of importations for biological control of insect pests and weeds in New Zealand. Biocontrol Science and Technology 3(4): 387-404
