Australian Journal of Entomology (2007) 46, 167-175
Michael J. Furlong and Myron P. Zalucki (2007)
Parasitoid complex of diamondback moth in south-east Queensland: first records of Oomyzus sokolowskii (Hymenoptera: Eulophidae) in Australia
Australian Journal of Entomology 46 (2), 167-175
Abstract: Surveys for parasitoids attacking larvae and pupae of Plutella xylostella L. (Lepidoptera: Plutellidae) were conducted in the Brassica agro-ecosystem of the Lockyer valley, south-east Queensland between 1999 and 2002. Parasitised hosts were collected from infested plants placed in Brassica crops during the growing season (February-October) and from the natural P. xylostella population on the common weed Rapistrum rugosum L. (Brassicaceae) during the summer production break (November-January). Five species of primary parasitoids were recorded and they ranked in order of abundance: Diadegma semiclausum Hellén (Hymenoptera: Ichneumonidae) > Diadromus collaris Gravenhorst (Hymenoptera: Ichneumonidae) = Apanteles ippeus Nixon (Hymenoptera: Braconidae) > Brachymeria phya Walker (Hymenoptera: Chalcididae) = Oomyzus sokolowskii Kurdjumov (Hymenoptera: Eulophidae). In crops, parasitoids were reared from 23 of the 30 P. xylostella cohorts studied; D. semiclausum was collected at 21 sites, O. sokolowskii at eight sites, D. collaris at six sites, A. ippeus at three sites and B. phya at a single site. The incidence and abundance of hosts parasitised by D. semiclausum increased markedly in winter and early spring months and parasitism rates as high as 95% were recorded. Diadromus collaris and O. sokolowskii were recovered at low levels throughout 2000 and 2001 but parasitism rates never exceeded 11% or 8%, respectively. Parasitism rates are compared with other mortality factors and the contribution that each species of parasitoid makes to the biological control of the pest in the region is considered. Oomyzus sokolowskii has also been reared from P. xylostella collected in Tasmania and Western Australia. This study is the first report of the incidence O. sokolowskii in Australia; however, its wide distribution indicates that its establishment is not a recent event.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Michael J. Furlong, Myron P. Zalucki
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
surveys/distribution/isolation
population dynamics/epizootiology
