Biocontrol introduction
Target pest: Phylacteophaga froggatti (Hymenoptera: Pergidae), Eucalyptus sawfly
Agent introduced: Bracon confusus (Hymenoptera: Braconidae)
Imported:
1986, 1987, 1988
Import source:
Australia
Import notes:
Faulds (1990) - consignments of Bracon (488 females and 552 males) were sent to New Zealand in December 1986 and January 1987 from Melbourne, Australia. More than 600 adult progeny were reared, but this attempt was abandoned when it became obvious that no mating had occurred, resulting in only male progeny. Three further consignments were imported in December 1987 and January 1988; except for a few field-collected females, these parasites were collected as cocoons in Australia and imported mostly as adults. Although only one species of Bracon had been recorded as a parasite of P. froggatti in Australia, it was discovered two distinct species of Bracon with different mating requirements had been imported; these were subsequently described, in 1989, as Bracon phylacteophagus and B. confusus. Bracon confusus made up only approximately 2.5% of the imports in both 1986-87 and 1987-88. Rearing of B. confusus was discontinued in order to concentrate on B. phylacteophagus, the principal parasite of P. froggatti.
Released:
1988?
Release details:
Faulds (1990) - Bracon confusus was not deliberately released. However, it is possible that five females released at Maungatapu (Bay of Plenty, North Island) on 25 February 1988 as part of the B. phylacteophagus release programme could have been B. confusus, as it was subsequently discovered that most female emergences in the laboratory between the previous release date (22 February) and 25 February were B. confusus [see Faulds (1990) entry in 'Import notes' section].
Establishment:
NZOR (2023) - there are no records of B. confusus in New Zealand.
References
Faulds W (1990). Introduction into New Zealand of Bracon phylacteophagus, a biocontrol agent of Phylacteophaga froggatti, eucalyptus leaf-mining sawfly. New Zealand Journal of Forestry Science 20(1): 54-64 https://www.scionresearch.com/__data/assets/pdf_file/0007/59965/NZJFS20154FAULDS.pdf
NZOR (2023). New Zealand Organisms Register. Accessed 14 August 2023. https://www.nzor.org.nz/
