Gypsy moth (Lymantria spp.)
Exotic to Australia
Life form: Insect
Origin: China, East Russia, Southern Europe and Northern Africa
Distribution: Asia, Europe, North Africa, North America
Features: Males and female moths differ in sizing and colour,
ranging from yellow to grey brown colour and wingspan
Pathways: Nursery stock, freight, cargo ships, containers
At risk: More than 1000 plant species
Originating from China and Far East Russia the Asian gypsy moth has now spread and established in Korea, Japan and Europe. The European gypsy moth which originated from southern Europe and Northern Africa has spread to North America.
Gypsy moths are destructive pests of forests and horticulture and include three sub-species:
- Asian gypsy moth (Lymantria dispar asiatica)
- Japanese gypsy moth (Lymantria dispar japonica)
- North American/European gypsy moth (Lymantria dispar dispar).
Hybrids between these sub-species have been observed.
Gypsy moths pose a high biosecurity risk to Australia because of their tendency to hitchhike and their high reproductive rate. If gypsy moths established in Australia they would be extremely difficult and expensive to manage, partly because of their broad host range.
European strains of the gypsy moth hold great potential for damage to commercial radiata pine plantations where this species is utilised in plantation forestry, such as in New Zealand or Australia.
Preventing an incursion in the first place is a high priority for government and industry, and we need your help.
How to identify Gypsy moth (Lymantria spp.)
Everyone needs to keep an eye out for gypsy moths and egg masses.
The gypsy moth would most likely enter Australia in the egg stage, as it spends a significant proportion of its life cycle on non-host material as eggs. Asian gypsy moth egg masses are tolerant of extremes in temperature and moisture.
Egg masses can be transported domestically or internationally on:
- cargo ships
- nursery stock
- plant parts
The flight season (July – September) until hatching time (April – May) is the most likely period that viable eggs could enter Australia.
Caterpillars have a significant appetite and high populations can completely defoliate trees causing them to die. Two to three years of defoliation often result in significant tree death, especially if the trees are also stressed by drought.
Gypsy moths produce one generation per year and mature through four main life stages.
- They begin as tiny eggs laid in large masses. The egg masses are covered in yellowish hair, are about 20 by 40 millimetres in size and can contain more than 1000 eggs.
- The freshly hatched hairy larvae can spin silk threads helping them balloon (drift on air currents) for up to eight kilometres, if weather conditions are right.
- Later stages of larvae vary in colour but have two distinctive rows of raised spots along the back – usually five pairs of blue and six pairs of red from head to tail.
- The larvae then pupate and emerge as adults.
Adult males are of a grey-brown colour and a wingspan of 30-40mm and females are pale yellow with wavy dark brown bands across the forewing and have a wingspan of 40-70mm.
Gypsy moths can be a serious nuisance in urban environments.
- Host garden plants and hosts in recreation areas are often defoliated.
- Where there are high numbers, caterpillars sometimes crawl into houses and vehicles.
- They can contaminate water with their frass and their hairs can provoke allergic reactions.
If you work around imported goods you need to look for gypsy moths or their egg masses attached to:
- nursery stock
- shipping containers
Growers and home gardeners
Take action if you find a moth or egg mass that looks like it could be a gypsy moth.
The caterpillars feed on the leaves of more than 1000 species of trees, such as:
- fruit trees
- ornamental plants.
Older larvae will also feed on a number of conifers such as:
Check these plants regularly.
Good biosecurity measures including inspecting equipment and packaging before it arrives on your property will help prevent entry and establishment. It is also a good idea to keep records of plant purchases, particularly where they are sourced from.
Gypsy moths are a minor risk to human health and are regarded as a nuisance pest because they cause reduced tree growth, crown dieback and its eventual death.
Keep Gypsy moth (Lymantria spp.) out of Australia
All Australians and international tourists have a role to keep out exotic pests and diseases.
Gypsy moths are native to northern hemisphere countries. Australia remains free of this exotic pest. We need your help to keep it this way.
Check what you can and cannot bring into Australia, whether you are a:
Gypsy moths are aggressive invaders
While all gypsy moth species pose a biosecurity risk to Australia, the risk of entry and establishment varies depending on the biology of each species. The female European gypsy moth cannot fly, potentially limiting the distance over which it can spread. However, even flightless gypsy moths can potentially spread through the ballooning of larvae. The females of other species are capable of flying, allowing them to lay their eggs on cargo, ships and aircrafts, which may disperse them internationally.
Gypsy moths can spread via numerous pathways, including:
- flight – adult female Asian and Japanese moths are able to fly up to 40km
- on host plants - newly hatched caterpillars move up the plant to feed on young foliage
- wind (first and second instar caterpillars).
Import restrictions and biosecurity measures
Some items, by law, are subject to certain import conditions to be allowed into Australia. Please check the Biosecurity Import Condition System (BICON).
Be aware of any gypsy moth biosecurity measures that may be in place for incoming goods and conveyances. Industry advice notices are reviewed regularly and could change.
Secure any suspect specimens
Containment is crucial. If you suspect you’ve seen a gypsy moth, take a photo and record the location.
Inspect area for egg masses and place them in a sealed container.
Report detections of exotic pests
Any detections of gypsy moths must be reported to the authorities.
If you receive or work around goods imported from overseas, including mail, you need to be vigilant to gypsy moths and other exotic pests. If you see an unusual pest, secure the goods to limit the movement of the pest and immediately report it to the Department of Agriculture and Water Resources SEE. SECURE. REPORT. Hotline 1800 798 636 or by using the online form.
Growers and home gardeners
If you see gypsy moths or anything unusual, report it to the Exotic Plant Pest Hotline 1800 084 881. This will put you in touch with the Department of Primary Industries or agriculture in your state or territory.
When reporting your concern, you will be given advice on handling the specimen and what to do next until an officer can investigate.