Gum Tree Weevil

Appearance

This weevil is greyish-brown with a light coloured transverse band. It is about thirteen millimetres long and not readily distinguishable from the closely related weevil, "Gonipterus gibberus", which shares the same common names. The larvae are yellowish-green with black markings and have three dark green stripes on the abdomen which distinguish them from larvae of "G. gibberus".

Distribution

The gum tree weevil is endemic to Australia where "Eucalyptus" trees are native. The weevil has spread to New Zealand, China and in Africa to Kenya, Lesotho, Madagascar, Malawi, Mauritius, Mozambique, South Africa, St. Helena, Swaziland, Uganda and Zimbabwe. Also to Brazil, Chile and Uruguay and the United States, and in Europe to France, Italy, France, Portugal and Spain.

Evolution

Over a period of about three months, adult female gum tree weevils lay about two hundred eggs in batches of about ten in grey coloured capsules. These are attached to the upper or lower sides of the leaves and hatch after about a week. The larvae begin to feed on leaves and young shoots. After moulting three times, the larvae crawl or fall to the ground where they pupate a few centimetres beneath the surface. The weevil's life cycle takes seven to eleven weeks from egg laying to maturity, depending on the temperature. In Mauritius there are about four generations annually and the weevils breed throughout the year. In South Africa there are two generations and they overwinter as adults.