Stored Grain Insects



Parasitic wasp

Various spp.



Parasitic wasp (Anisopteromalus calandrae)
Courtesy of CSIRO Division of Entomology

The adults of the parasitic wasp vary considerably in size, form, and coloration, but the majority resemble slender wasps. Wasps of stored product pests are generally less than 2 mm long and do not sting. An example of a typically found Western Australian stored product parasitic wasp is Anisopteromalus calandrae. It is 1 - 1.5 mm long with a metallic dark green to black colour. It is a parasite of beetle larvae such as Sitophilus spp. and Rhyzopertha dominica.

Life cycle
The adults attack and lay eggs directly into live beetle and moth larvae. The wasp larvae develop in or on the host, and emerge from the host as adults. The host larvae are killed on emergence. The adult wasps are short lived and do not feed. They fly readily, are attracted to light and are often seen walking over the surface of grain.
These parasites help to reduce the number of pest insects, thus taking an edge off the amount of damage from pests. The presence of a large number of these wasps ususally indicates the presence of an established pest population.
Control is unneccessary as these insects aid in pest control.