Cover image: An adult spotted lanternfly (Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org)
The spotted lanternfly (Lycorma delicatula) is a high priority plant pest in many countries overseas. At the time of writing, the spotted lanternfly had not been found in Australia, which is fortunate for home gardeners and our primary producers. However, vigilance and early detection in the case of an incursion will be important in keeping Australia free from this pest.
The spotted lanternfly has been shown to feed on a variety of tree species including apple, stone fruit, grapes, walnut, and a range of ornamental species. Over recent years, as the pest has spread and researchers have learnt more about its biology in new areas, the ‘host list’ for spotted lanternfly has steadily expanded. It has the potential to be damaging to Australian natural environments, however it is difficult to predict what native tree species may play host to this insect.
A preferred host, the Tree of Heaven (Ailanthus altissima), is naturalised in Australia and is commonly used in garden landscaping and streetscaping, particularly in urban areas. This means that an incursion of spotted lanternfly into an urban area (for example, after hitching a ride on incoming cargo), would be supported by an abundance of trees that could form a ‘green bridge’ to nearby native and production areas.
In the US, where spotted lanternfly is a recent arrival, this species is rapidly spreading throughout east coast states. Tracking its spread has been aided by both the striking visual appearance of this insect and contributions from citizen scientists.
What does it look like?
Like many insects, the spotted lanternfly has a lifecycle that involves several distinct stages: egg, nymph, and adult. We call this a ‘hemimetabolous’ lifecycle, where growth to the adult stage does not involve development through a pupal (cacoon) stage as you would see in moths and butterflies. Instead, the nymph will undergo a series of moults, growing larger and more distinctive features with each moult, until it has grown all the features required of an adult.
While individual spotted lanternfly eggs would be difficult to discern by eye, the way in which these eggs are laid (30-50 eggs enclosed in a capsule that looks a bit like a clay coating) makes detection easy, once you know what you’re looking for. On trees, relatively smooth bark is the preferred substrate for egg lay. Egg masses may be laid on inanimate substrates, such as firewood, rusty metal, car tyres and garden furniture, increasing the risk of moving the insect to new regions.
After egg hatch, a nymph will emerge. This very young nymph will be black, with white spots, and it will move through four distinct nymphal growth stages over several months. When the final nymphal stage is reached, the spotted lanternfly becomes more colourful, turning predominantly red, with white and black markings.
The adult life stage is by far the most eye catching. By this stage the spotted lanternfly has grown a pair of wings. When folded, the forewings show large black spots at the proximal end (closest to the body), which become many rows of black lines about two thirds of the way down the wing. If you were to look closely you would see that these black lines look a bit like brickwork masonry.
The hind wings are even more striking, with a large bright red patch covering most of the posterior region (farthest from the head) and black spots being present against the red backdrop. The rest of the hindwing is patterned black and white. The abdomen is yellow with black banding.
This species remains relatively small throughout its lifecycle, with the adult reaching 24-27mm from head to folded wingtip and nymphs ranging from 3.6mm-14.88mm.
Why is spotted laternfly a concern?
The spotted lantern fly is an hemipteran planthopper. Like other planthoppers the spotted lanternfly uses a tough piercing stylet to feed on the nutrient-rich phloem (sap) of its host. This is similar to a mosquito taking a blood-meal.
As you would imagine, constant feeding by many spotted lantern flies can leave the plant host looking less vigorous. This may manifest as leaf wilt and discolouration, leaf drop, and stunted growth. Other impacts include the build-up of sooty mould secretions at the base of infested plants, which can attract other nuisance pests, such as ants and wasps. Spotted lanternfly feeding can stress a plant host, leaving it susceptible to secondary impacts such as disease, reduce the yield of fruit-bearing trees, or in the case of grape infestation can result in complete die off of the vine.
Staying mindful of your surroundings, be it your garden, a local park, or your farm, will help you identify what is normal and what may be a ‘red flag’.
Suspect detection of the spotted lanternfly should be made to the Exotic Plant Pest Hotline, which will direct you to your appropriate state department of agriculture. The number to call is 1800 675 888. If you are hunting for spotted lanternfly as part of a biosecurity blitz, you can use the MyPestGuide Reporter App.
Watch this video to learn how to identify the Spotted lanternfly
- SLF identification and awareness – Gardener fact sheet
- SLF identification and awareness – Forester fact sheet
The project ‘Spotted lanternfly (Lycorma delicatula) biology, ecology and awareness in the Australian environment’ is running from October 2020 to April 2021. The project is funded by the Australian Plant Biosecurity Science Foundation and the Department of Agriculture, Water and the Environment and is led by Cesar Australia. Project collaborators are Agriculture Victoria, NSW DPI, Plant Health Australia, and Greenlife Industry Australia.