Ophelimus maskelli

Eucalyptus gall wasp

Description

Ophelimus maskelli, commonly known as the eucalyptus gall wasp, is a tiny chalcid wasp about 1 mm long. Native to Australia and New Zealand, it has become invasive in regions such as the Mediterranean, the Middle East, North Africa, and parts of the United States. Ophelimus maskelli is a uniparental leaf galler, meaning it reproduces without males. Adult females oviposit directly into the leaf blades of eucalyptus trees, with a single female capable of laying an average of around 100 eggs. Each egg induces the formation of a gall, where larvae develop and pupate. The adult wasps emerge from these galls. In some regions, like Israel, up to three generations per year have been reported. Management strategies for controlling Ophelimus maskelli include the selection of resistant planting material and biological control. The parasitoid wasp Closterocerus chamaeleon has been particularly effective as a biological control agent, successfully reducing O. maskelli populations in areas like Israel and the Mediterranean.

Symptom

The primary symptom is the formation of small galls, which are abnormal, rounded growths on the eucalyptus leaves. They can be very numerous on the leaves. Heavy infestations result in significant galling, leading to widespread defoliation and stunted growth in eucalyptus trees.

Tree Species: Eucalyptus

Part of a plant- attacked: Leaf / Needle

Pest significance: Harmful

Pest Category: Insects

Invasive Species: Yes

Present in EU: Yes