Biocontrol introduction
Target pest: Agromyzidae (Diptera: Agromyzidae), leaf miners
Agent introduced: Chryrsocharis sp. (Hymenoptera: Eulophidae)
Imported:
1969-71
Import source:
Pakistan
Import notes:
Cameron et al. (1989) - because resources for mass-rearing in New Zealand were lacking, biocontrol agents for the biocontrol programme against agromyzids were reared in Pakistan and sent to New Zealand by the Commonwealth Institute of Biological Control in Pakistan. The host agromyzids in Pakistan from which all parasitoids for New Zealand were obtained were Chromatomyia horticola and Liriomyza brassicae. There is some confusion about the Chrysocharis sp. sent to New Zealand. The first shipment of parasitoids from Pakistan arrived in October 1969 and included 47 adults of a eulophid questionably identified as Chrysocharis sp. Three consignments in April 1970 included 204 adult Chrysocharis sp. In November 1970, two consignments contained adult parasitoids tentatively identified as Chrysocharis sp., but were later determined to be Hemiptarsenus semialbiclavus. The last two consignments of parasitoids from Pakistan, in April 1971, contained 280 adult Chrysocharis sp.; there is little doubt that these were Chrysocharis sp. and not misidentified H. semialbiclavus.
Released:
1970
Release details:
Cameron et al. (1989) - the 47 adult putative Chrysocharis sp. imported in October 1969 [see Cameron et al. (1989) entry in ‘Import notes’ section above] were not released. Releases at Ashburton in the South Island were made from the 204 adults imported in April 1970. Of the 280 C. sp. adults imported in April 1971, 130 were released at Ashburton; the remainder may not have been released. In total, at least 177 Chrysocharis sp. were released.
Establishment:
Cameron et al. (1989) - Chrysocharis sp. did not establish from the releases made as part of the biocontrol programme against agromyzids. A Chrysocharis sp., probably C. pubicornis, was probably already present in New Zealand parasitising Agromyzidae before this programme began.
General comments:
Cameron et al. (1989) - some species of Agromyzidae (leaf miner flies) present in New Zealand are serious pests overseas, but their pest status in New Zealand is uncertain. Liriomyza chenopodii may damage beet and spinach; Chromatomyia syngenesiae is mainly a pest in glasshouses, where it damages Asteraceae, especially chrysanthemums, though it has been regarded as not important in cultivated crops; Cerondontha australis is frequently found in many grasses, including cereals, though apparently does not cause significant damage. The cosmopolitan pest Liriomyza brassicae is not considered a significant pest in New Zealand. In the late-1960s reports of apparent agromyzid leaf miner damage to brassicas led to the instigation of the biocontrol programme against agromyzids. However, during the course of the programme it was discovered that the damaging leaf miners were not Agromyzidae but two species of Drosophilidae.
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.
