Leptocybe invasa (Eucalyptus Stem Gall Wasp)

This wasp attacks a number of eucalypt species including E. bridgesiana. It was only discovered in 2000 after the galls were found on overseas plantations of River red gums (E. camaldulensis), but it is indigenous to Australia.

This eucalyptus gall wasp is tiny, only just over 1mm in length and lives for only about 1 week. It is mainly brown in colour with a slight blue green iridescence on its body and has yellow legs. The female wasp can reproduce asexually and injects her eggs into new leaf buds of suitable eucalypts. This can kill the leaf bud but, if it survives, the bud swells and develops corky tissue internally. The exterior of the swelling becomes glossy and turns from green to pink, then dark red and eventually a dark brown. The wasp larva develops inside the gall and emerges as an adult wasp after 3-4 months.