Biocontrol introduction
Target pest: Pineus laevis (Hemiptera: Adelgidae), pine twig chermes, pine woolly aphid
Agent introduced: Leucopis tapiae (Diptera: Chamaemyiidae)
Imported:
1932
Import source:
England
Import notes:
Cameron et al. (1989) - six consignments of 'Leucopis sp.' larvae [see Cameron et al. (1989) entry in ‘General comments’ section for subsequent identification to species level] arrived in New Zealand from England between April and June 1932. Some had pupated in transit, but larval mortality had been high. Many adults emerging in June-August died in the cold weather. Laboratory and insectary rearing on Pinus radiata infested with P. laevis failed and all available adults were released. A smaller, unspecified number of 'Leucopis sp.' was imported in 1934, from which releases were also made.
Released:
1932
Release details:
Cameron et al. (1989) - all available adults emerging from the 1932 importations were released during May-August 1932 in the Nelson district of the South Island; eight liberations totalling 145 flies. A 1935 publication also noted a release of 25 adults at Taupo, North Island in September, but no year is mentioned, and it is possible this release was from the 1934 importation since it is only in this year that a release at Taupo is mentioned in a 1936 publication. From the 1934 importation, releases were made at Taupo and in the Nelson district.
Establishment:
Cameron et al. (1989) - many attempts at recovery were made following the releases but it was concluded by 1935 that establishment had failed or succeeded only to a very limited extent. The first records of establishment came in 1954 from Whakarewarewa (Rotorua, Bay of Plenty, North Island) and Balmoral (North Canterbury, South Island). Leucopis tapiae was subsequently found in many collections at various localities in both islands.
Impacts on target:
Cameron et al. (1989) - Leucopis tapiae is the most important predator of the P. laevis in New Zealand and is easily detected among P. laevis collected from pines anywhere in New Zealand.
Cameron et al. (1993) - Leucopis tapiae is categorised as exerting “substantial” control (defined as “other control measures are only occasionally required”) over P. laevis.
Impacts on non-targets:
Cameron et al. (1989) - Leucopis tapiae has not been found among, or bred from Dreyfusia (= Adelges) nordmannianae, which infests firs (Abies spp.) and is the only species in the family Adelgidae, other than P. laevis, in New Zealand.
General comments:
Cameron et al. (1989) - there has been some confusion over the identity of the Leucopis sp. introduced to New Zealand. A 1935 publication considered at least two species were present in the 1932 importations, but this is unknown as it appears no voucher specimens were kept. Forest Research Institute and Cawthron Institute reports in 1935 state the species to be L. obscura, a name that was used until specimens from New Zealand were determined by [Canadian expert] J. F. McAlpine to be L. tapiae in 1971.
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
