Adult and larval hoverfly communities and their parasitoid fauna in wheat in New South Wales, Australia

Abstract

Aphidophagous hoverfly adults and larvae were collected in yellow pan water traps placed on the ground in a wheat crop in New South Wales. The majority of adults (84%) and larvae (91%) were Melangyna spp.; the remainder comprised Simosyrphus grandicornis Macquart. The distribution profile of larval size derived from their body outline was modelled for the dominant species, Melangyna viridiceps Macquart, and each of the three instars was represented by a peak in the distribution. Mean numbers of syrphid larvae and aphids per wheat stem were 0.12 ± 0.02 and 0.55 ± 0.09 respectively. Seventeen of 121 (14%) dissected third-instar larvae contained parasitoids. Larvae also fed on small lepidopteran larvae.