Exotic spongy moth

Exotic spongy moth (Lymantria dispar) is an insect.

There are several important exotic spongy moth sub-species, including European spongy moth (L. d. dispar), Asian spongy moth (L. d. asiatica) and Japanese spongy moth (L. d. japonica).

Adults

• Male and female moths look quite different to each other.
• Males are grey-brown with darker wing markings, and have feather-like antennae. They have a wingspan of 3–4cm.
• Females are whitish, with black markings on the wings, and have finer antennae than the males. They are also larger, with a wingspan of 4–7cm.
• Unlike most other moths, spongy moths are active during the day.

Eggs

• Usually laid on hard surfaces such as tree trunks or branches, or rocks, but also on human-made objects such walls, fences, vehicles, and shipping containers.
• Laid in masses of 50 to 1200 eggs.
• Egg masses can be 2–5cm long, buff coloured with a dense, yellowish coating of hair sloughed off from the female abdomen.

Larvae

• All larval stages are very hairy.
• The colour of different subspecies can vary.
• Early growth stages (instars) are grey-black and about 3mm long.
• Later growth stages vary in colour, with black, yellow, blue and red patterns, but all have a characteristic double row of dots along their back with 5 pairs of blue dots followed by 6 pairs of red dots (see image).
• Males grow to 40–50mm and females to 60–70mm long.

Pupae

• Dark brown, 2–4cm long.
• Are positioned in bark crevices and other cryptic locations.
• Adult moths emerge from pupa.

Plant stage and plant parts affected

All stages of plant growth (seedlings to mature plants) can be affected.

Larvae feed on leaves and flowers.

Plant damage

The main damage is caused by feeding larvae. Severe infestations of larvae can defoliate plants. Feeding damage can make plants more susceptible to secondary pests or diseases.

There are a number of other hairy larvae or caterpillars that can resemble spongy moth larvae, including several Australian native or naturalised Lymantria species such as L. antennata, L. lunata, L. nephrographa and L. pelopsila.

Find out more about native Lymantriidae moths and their hairy caterpillars.

Exotic spongy moth larvae are distinctive from native species as they have a high reproductive rate resulting in severe infestations that can defoliate plants, and the larvae have a distinctive double row of dots along their back.

Exotic spongy moths have an extremely broad host range, and are able to complete their life cycle on over 650 plant species worldwide.

Hosts include Australian native species (including Eucalyptus), forest, orchard and ornamental trees.

View a detailed host list for exotic spongy moth hosts.

• There is usually 1 exotic spongy moth generation per year.
• The specific timing of each life cycle stage is dependent on environmental conditions.
• In the summer, female moths produce a pheromone to attract males for mating.
• After mating, the female moth lays 50–1200 eggs on a host plant or a wide variety of other surfaces.
• Both the male and female moths live for about 1 week, dying after mating and egg laying.
• Egg masses typically remain dormant over winter (diapause).
• In spring, when plants are flushing with new growth, the larvae emerge from the eggs.
• The larvae climb to the canopy to find young leaves to feed on.
• Young larvae can spin and suspend their bodies on a silk thread and be carried by the wind to new host plants.
• The first 3 growth stages (instars) feed during the day. Later growth stages (4th instar onwards) mainly feed at night and tend to hide during the day on the trunk or in leaf litter.
• During severe infestations, feeding can continue during the day and night.
• The larval stage lasts about 6 to 8 weeks (5 instars for males, 6 for females).
• In summer, the larvae develop into pupae.
• The pupae mature for 7–14 days before adult moths emerge to start the next generation.

• Exotic spongy moth could cause environmental and economic damage to our native bushland, forests, tree crops and gardens.
• Severe infestations can defoliate trees and shrubs, increasing their susceptibility to secondary plant pest and disease attack.
• Nursery, tree crop (fruit and nut crops) and forestry industries would be most affected by this pest.
• Additionally, some people are allergic to the hairs on exotic spongy moth larvae.

Exotic spongy moth adults can lay their eggs on plants and plant related material, and on human-made objects. As a result, spongy moth eggs and/or larvae could be introduced to Australia on imported goods, shipping containers, crates, machinery and motor vehicles, as well as on plant material.

To minimise this risk, the Australian Government regulates imports of plant material and other risk items that could carry exotic spongy moth.

Once established in an area, exotic spongy moth can spread short distances effectively on their own. Young larva can 'balloon' on a silk thread in the wind, and the adult moths can fly*.

*Except for female European spongy moth adults which cannot fly.

Inspect your plants regularly for the presence of severe leaf damage and defoliation.

Look for:

• larval droppings on leaves
• very hairy larvae feeding on fresh growth
• older life stage larvae with a characteristic double row of 5 pairs of blue dots followed by 6 pairs of red dots on their back
• larvae with silk strands
• buff egg masses with a yellowish coating
• dead adult moths.

If you suspect you have seen exotic spongy moth, take photos of moths, larvae and egg masses and record the location. Report suspected exotic spongy moth to Biosecurity Queensland immediately on 13 25 23 or contact the Exotic Plant Pest Hotline on 1800 084 881.

Protect your farm from plant pests and diseases:

• Protect your farm from emergency plant pests
• Understand good farm biosecurity
• Biosecurity manual for the plantation timber industry (PDF, 1.9MB)
• Biosecurity manual for the nursery production industry (PDF, 3MB)
• Visit the farm biosecurity website

Call 13 25 23 if you find a plant you suspect may have Exotic spongy moth to seek advice on control options.

Exotic spongy moth is prohibited matter under the Biosecurity Act 2014.

Report suspected Exotic spongy moth to Biosecurity Queensland immediately on 13 25 23 or contact the Exotic Plant Pest Hotline on 1800 084 881.

If you think you have found Exotic spongy moth, you must take all reasonable and practical steps under your control to minimise any associated risks. This is called a general biosecurity obligation (GBO).

The Australian Department of Agriculture, Fisheries and Forestry has import conditions in place for importing plants and plant products.