History of an invader, Scaptomyza flava (Fallen, 1823) (Diptera: Drosophilidae)

In New Zealand, the European leaf mining fly, Scaptomyza (Scaptomyza) flava (Fallen, 1823) (Diptera: Drosophilidae), is a pest of gypsophila and brassicas. Scaptontyza flava was first found in Levin (March 1964) and in 1965 was found in Hastings (March), Lincoln (July), and Nelson (December). By January 1968 it was found in Auckland and Gisborne. Voucher specimens in New Zealand show the species was correctly identified by the Commonwealth Institute of Entomology in 1965. However, this information was lost, and parasitoids of Agromyzidae were released (1969-71) to control what was initially assumed to be an agromyzid leaf miner of brassicas. The identity of the fly as S. flava was confirmed by Bock in 1988. In this study, six New Zealand insect collections were examined and field collections were made to confirm host associations, parasitism, and colonisation. Two parasitoids have been reared from S. flava in New Zealand, and overseas at least two other parasitoid species are known from this species. This investigation emphasises the need for good communication about new pests and proper care for voucher specimens.