T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Beetle (Longhorn Eucalyptus borer) Phoracantha semipunctata

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Family: Cerambycidae
Genus: Phoracantha
Species: P. semipunctata
Binomial name: Phoracantha semipunctata
Common names: Eucalyptus longhorned borer, Australian Eucalyptus Longhorn beetle,

Phoracantha semipunctata is an invasive, longhorn, beetle pest species of many species of Eucalyptus, especially E. globulus and E. viminalis It probably was introduced to New Zealand from Australia in the 1870s in railway sleepers. It is now widespread where eucalypts are grown. At present, it is not of economic significance because eucalypts are not being regularly milled.
Phoracantha semipunctata ranges from 14-30mm in length and they have a complex pattern of cream and brown markings on the elytra (wing cases). There is a cream coloured spot at the rear end of each elytron. There is also a spine at the rear of each elytronThe female’s the antennae are as long as her body but those of the male are considerably longer.

During summer months females lay their eggs in crevices of eucalypts bark. Logs with no bark are attacked. Eggs hatch within 14 days. The larvae are up to 30 mm in length. They bore under the bark into the sap-wood of milled logs and that of dead or dying trees. The larvae feed for about 4 months leaving galleries up to 2 metres in length. When they are due to pupate they burrow obliquely into the wood. Pupation takes about 10 days.

In California where this pest has been introduced, they are using Avetianella longoi, a parasitic wasp that specificity parasites the eggs of Phoracantha semipunctata. This wasp has 90+% parasitism rate. 

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0