Aphid Parasite Wasp - Aphidius or Trioxys sp.
Family BRACONIDAE
This page contains pictures and information about Aphid Parasite Wasps that we found in the Brisbane area, Queensland, Australia.
- Body length 2mm
Aphid Parasitic Wasps are the very small wasps. They fly actively searching for aphids. The easiest way to take their pictures is when they get caught in a spider web. The picture was taken from the spider web over a aphids colony in our backyard in spring season. The wasp is black in colour with black vein on its transparent wings. Their antenna is about 2/3 of their body length.
The Parasitic Wasps can be found amongst the aphids colony, although they may not been seen easily. In the aphids colony, some of the aphids population are dull brown in colour, which are parasitised individuals. The female search the aphids with its antenna. When a suitable host aphids is found, the wasp bends its abdomen forwards, inserts its ovipositor into the aphids body to lay egg. This take about two second, then the wasp keep on searching another victims.
In the first picture the wasp is just inserting her ovipositor into an aphid's body, to lay an egg inside. The wasp larvae will hatch and live inside the aphid's body. The parasitised aphid will turn into dull brown in colour. About a weeks or so the larvae pupate inside the aphid. Few days later an adult wasp emerge and leave a aphid shell with a circular hole. In the second picture there are three fat yellow-brown "mummies", they are parasitised by the wasp. Notice the two on the upper side of the picture, are empty, the wasps had come out already.
The above picture are taken at the same flower buds between one week. The first picture showing the flower buds are fully covered with aphids. But over half of the aphids population is yellow-brown in colour and fat, i.e., they are parasitised by the wasp. The second picture, one week later, shows most of the yellow-brown aphids became an empty shell with a small open hole.
- Reference:
- 1. Insects of Australia, CSIRO, Division of Entomology, Melbourne University Press, 2nd Edition 1991, pp 948.
- 2. Northern Territory Insects, A Comprehensive Guide CD - Graham Brown, 2009,
