Features: Medium sized moths that infest and destroy many kinds of plants; large hairy caterpillars up to 7 cm long, with distinctive red and blue spots. They have formerly been referred to as ‘gypsy’ moths. Where they're from: Asia, Europe, North Africa, North America How they spread: Imported nursery stock, freight, cargo ships, containers At risk: More than 1000 plant species including eucalypts and pine forests, fruit and nut trees
Spongy moth infesting a tree trunk. Note the dark yellow egg masses. Karla Salp, Washington State Department of Agriculture, Bugwood.org.
Spongy moth species (Lymatria spp.) are destructive pests of forests and horticulture that are present in many areas of the world. They attack more than 1000 species of plants including fruit and nut trees, plantation forests, native species and ornamental trees. They breed quickly, laying egg masses that contain 100 – 1200 eggs. Large populations of caterpillars able to completely defoliate trees causing them to die.
The moths lay yellow egg masses on hard surfaces, usually tree trunks but also on logs, outdoor furniture, nursery stock, pallets, shipping containers and on the hulls and rigging of ships. This makes them good at hitchhiking around the world. Locally they can fly, but some also spread as larvae on silk threads.
If a spongy moth species established in Australia they would be extremely difficult and expensive to manage, and would cause problems for many farmers, foresters, threaten our natural environment and impact our gardens.
Importing goods
To keep spongy moths out of Australia, never ignore Australia’s strict biosecurity rules.
A spongy moth would be most likely to enter Australia in the egg stage. Look for dark yellow egg masses on:
cargo ships
commodities
containers
freight
nursery stock
plant parts
vehicles.
The flight season (July – September) until hatching time (April – May) is the most likely time when eggs could enter Australia.
Also look out for the pest in the caterpillar stage, when it is large (up to 7 cm long) dark and hairy with two distinctive rows of blue and red raised spots along the back.
As moths, adult males are grey-brown with a wingspan of 3-4 cm and females are pale yellow with wavy dark brown bands and a larger wingspan of 4-7 cm.
Asian spongy moth (Lymantria dispar) caterpillars have distinctive pairs of blue and red spots along their length, and can grow up to 7 cm long. Karla Salp, Washington State Department of Agriculture, Bugwood.org.The highly invasive spongy moth species has a wingspan of 3-7 cm. This is the light-coloured female. Karla Salp, Washington State Department of Agriculture, Bugwood.org.
Caterpillars can strip trees of all foliage eventually killing them. Karla Salp, Washington State Department of Agriculture, Bugwood.org.
Where to look
Importers
If you work around imported goods you need to look for spongy moths or their egg masses attached to:
planes
commodities
freight
nursery stock
shipping containers
vehicles
vessels.
Growers and home gardeners
Look out for egg masses, caterpillars and moths on trees including:
eucalypts
fruit trees
rose
timber
birch
hemlock
pines
spruces
oak
ornamental plants.
Damage to crops
Spongy moths target:
forestry
nursery
fruit
nuts.
What to do
If you think you’ve found spongy moth:
take a photo
do not disturb the insect (this may be as simple as closing the doors on a shipping container or preventing access to an orchard)
collect a sample, if it is safe to do so and if it doesn’t disturb the insects.
