Biocontrol introduction
Target pest: Epiphyas postvittana (Lepidoptera: Tortricidae), light brown apple moth
Agent introduced: Xanthopimpla rhopaloceros (Hymenoptera: Ichneumonidae)
Imported:
1967, 1969
Import source:
Australia
Import notes:
Cameron et al. (1989) - parasitised E. postvittana pupae were collected in eastern Australia and Tasmania in 1967 and 1969 and imported into quarantine at Nelson. Four X. rhopaloceros emerged in 1967; 31 emerged in 1969, of which 12 were directly released.
Released:
1967
Release details:
Cameron et al. (1989) - in 1969, 12 adults were released into field cages at Nelson. Between 1967 and 1973 releases were made at Kerikeri, Hamilton, Kaingaroa Forest, Rotorua, Nelson and near Christchurch. Further releases were made in Christchurch during 1972, 1978-80 and 1984-87 from field collections.
Munro (1998) - a collection of approximately 200 X. rhopaloceros from Nelson was redistributed to Havelock North (Hawkes Bay) in 1980.
Establishment:
Cameron et al. (1989) - initially established from small releases made in Nelson but later disappeared. Confirmed established at Paihia in 1973 and during the next few years became very numerous and spread throughout the North Island. It was common in Wellington in 1985 and in 1986 was confirmed to be established in Nelson [although X. rhopaloceros was redistributed from Nelson to Havelock North in 1980 (see 'Release Details') so presumably it was well established in Nelson before 1986]. The attempts to establish it in Christchurch (1972, 1978-1980, 1984-1987) have not been successful.
Munro (1998) - the first North Island records of X. rhopaloceros came from Kerikeri and Hamilton in 1973. It now occurs from the northern extreme of the North Island to as far south as Murchison, Nelson and Blenheim in the South Island. It has been collected on the Aldermen Islands, 20 km from the Coromandel Peninsula.
Impacts on target:
Cameron et al. (1989) - a PhD study by C.J.Green in 1984 showed little interaction of the introduced parasitoids Trigonospila brevifacies, X. rhopaloceros and Glabridorsum stokesii with hosts on apple trees in Auckland. The study failed to show any regulatory role of these parasitoids, except perhaps for parasitism of Cydia molesta (oriental fruit moth) by G. stokesii. The circumstantial evidence of reduction in archipine tortricid populations in orchards has not been quantified.
Lo et al. (2018) - the establishment and subsequent spread of the parasitoids X. rhopaloceros, Trigonospila brevifacies and Glabridorsum stokesii added to overall leafroller parasitism by increasing parasitism of late larval and pupal stages [see Cameron et al. (1993) entry in 'General comments' section]. However, from 1994-1999 and 2008-2011 leafroller larvae collections in Hawke's Bay, X. rhopaloceros was not reported as a component of the parasitoid guild reared from three fruit crops (apple, grape, boysenberry), or as a component of the parasitoids reared from oak trees in shelter belts.
Impacts on non-targets:
Cameron et al. (1989) - X. rhopaloceros also parasitises a range of smaller tortricids in New Zealand, in addition to its normal archipine tortricid hosts.
Berry (1990) - the parasitoid complex reared from field-collected specimens of the native oecophorid moth Hierodoris atychioides was dominated by the introduced parasitoids Trigonospila brevifacies and Xanthopimpla rhopaloceros.
Munro & Henderson (2002) - Xanthopimpla rhopaloceros has been recorded parasitising native tortricid moth pupae on a few occasions in native forests.
General comments:
Cameron et al. (1993) - native tortricid pest species were included as targets in the 1967-69 programme against E. postvittana. By 1984, changing attitudes to conflicts between conservation and biological control were recognized and more specific consideration was given to the preservation of non-target native species.
References
Berry JA (1990). Two parasitoid complexes: Hierodoris atychioides (Butler) (Lepidoptera: Oecophoridae) and Iceya purchasi Maskell (Homoptera: Margarodidae). New Zealand Entomologist 13: 60-62
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
Lo PL, Walker JTS, Hedderley DI, Cole LM. (2018). Reduction in leafroller (Lepidoptera: Tortricidae) abundance in orchards and vineyards 1976-2016, in Hawke's Bay, New Zealand. Agricultural and Forest Entomology 20 (4): 505-513
Munro, V.M.W. (1998). A record of the releases and recoveries of the Australian parasitoids Xanthopimpla rhopaloceros Krieger (Hymenoptera: Ichneumonidae) and Trigonospila brevifacies Hardy (Diptera: Tachinidae) introduced into New Zealand for leafroller control. New Zealand Entomologist 21: 81-91
Munro, V.M.W. and Henderson, I.M. (2002). Nontarget effect of entomophagous biocontrol: Shared parasitism between native lepidopteran parasitoids and the biocontrol agent Trigonospila brevifacies (Diptera: Tachinidae) in forest habitats. Environmental Entomology 31 (2). 388-396
