Biocontrol introduction

Target pest: Hylastes ater (Coleoptera: Anthribidae), black pine bark beetle

Agent introduced: Rhopalicus tutela (Hymenoptera: Pteromalidae)

Imported: 1975, 1976

Import source: Austria

Released: 1975-77

Release details: Cameron et al. (1989) - 2,948 released at Kaingaroa, 4,625 at Woodhill, 489 at Waiuku, 449 at Whakarewarewa and 485 at Tokoroa

Establishment: Cameron et al. (1989) - not recovered. Romo et al. (2017) - from 1976 to 1985 bark beetle infested logs were collected from two of the release sites, Kaingaroa and Woodhill forests, for laboratory rearing, but no R. tutela specimens were ever recovered and it was assumed the wasp had failed to establish. In January 2015 R. tutela were collected from cut Pinus radiata logs heavily infested with Hylastes ater at Bottle Lake Forest Park, Christchurch, Canterbury. Two possibilities exist. R. tutela established from the 1970s releases and spread throughout New Zealand (they had only been released in Auckland and central North Island), though it would be surprising they had not been detected subsequent to the releases. Alternatively the wasp may have been accidentally reintroduced; potential hosts H. ater and H. ligniperda have been intercepted on multiple occasions at the New Zealand border. Either way, R. tutela appears to be established in New Zealand.

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.

Romo CM, Early JW and Massart X (2017). �Unestablished� biological control agent found in Canterbury 40 years later. New Zealand Entomologist 40: 16-21