Adult spotted lanternfly, wings open
Source: Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org.

Spotted lanternfly (SLF) is an invasive sap-feeding planthopper with the potential to harm agriculture and forestry in Ontario. It was identified in 2014 in southeastern Pennsylvania, United States (U.S.) and has spread throughout much of the mid-Atlantic and surrounding states, including those bordering the province of Ontario. The current distribution and pest status in the U.S. can be found by visiting New York States’ Integrated Pest Management (IPM) interactive map.

The Canadian Food Inspection Agency (CFIA) has added SLF to its list of regulated pests to help prevent the introduction and spread from infested areas. Spotted lanternfly has not been identified during surveys conducted by the Ministry of Agriculture, Food and Rural Affairs (OMAFRA) in Ontario, nor have any live specimens been intercepted by the CFIA in Canada to date. Report suspect sightings of SLF to the CFIA to assist with early detection.

Risks to agriculture and forestry

Spotted lanternfly is a risk to agriculture and forestry industries in Canada. It attacks various agricultural crops, landscape ornamentals and hardwood trees, including commercially important grapevines, hops, nursery plants, black walnut, birch and maple. The invasive Tree of Heaven (Ailanthus altissima) (TOH), widely distributed in the U.S. and parts of Canada, is a preferred host of older nymphs and adults but is not required for SLF to complete its life cycle.

Swarms of nymphs and adults damage plants directly by feeding on phloem (sap) from the stems and trunks, and indirectly by excreting large amounts of sugary honeydew that promotes the development of sooty mould and interferes with photosynthesis. Spotted lanternfly is considered a plant stressor and may contribute to the long-term weakening of established vines, shrubs and trees. Prolonged feeding has contributed to the death of grapevines, TOH and tree saplings in infested areas. More research is needed to determine the impact to other host plants and to overall ecosystem health. It is currently considered to be primarily a nuisance pest in residential landscapes.

Life cycle and identification

Spotted lanternfly has one generation per year and overwinters in the egg stage (Figure 1). In the fall, mated females lay rows of tan coloured eggs, 30–50 per mass, covered by a protective white waxy coating that turns grey, dries, and cracks over time (Figure 2). Eggs are cold tolerant and are expected to survive winters in southern Ontario;

Life cycle illustration of seasonal biology of spotted lanternfly
Figure 1. Seasonal biology of spotted lanternfly in Pennsylvania. Source: Invasive Species Centre.
Accessible description for Figure 1
Tree trunk with egg masses
Grapevine post with egg masses
Figure 2. Egg masses of varying ages on a grapevine post. Source: Heather Leach, Michigan State University.

Nymphs hatch from eggs in the spring (Figure 3) and progress through four developmental stages known as instars. The first three instar stages are black with white spots and the fourth is bright red with white spots and black bands, and approximately 13–15 mm in length (Figure 4). All nymphs are strong jumpers and are highly mobile. Early instars have a broad host range and feed on young shoots of perennials and annual plants. Fourth instar nymphs and adults typically restrict their feeding to woody tissues of grapevines, walnut, maple, birch, TOH and other hardwood species.

First instar nymphs and egg mass
Figure 3. First instar nymphs (3 mm) recently hatched from egg mass on the left. The egg mass on the right is older and shows exposed eggs that have already hatched. Source: Richard Gardener, Bugwood.org.
Early and late instar spotted lanternfly nymphs
Figure 4. Early and late instar SLF nymphs. Source: Steve Ausmus, USDA-ARS.

Based on observations in Pennsylvania, adults begin to appear mid-July and are active through November, until killed by a hard frost. Activity is not expected in December in southern Ontario. They are large, brightly coloured insects approximately 25 mm in length and 12 mm wide with wings folded at rest. The forewings have black spots on a light tan to grey background, with a dark net-like appearance at the tips (Figure 5). When exposed, hindwings are bright red with spots at the base and black at the tip, separated by a white band (Figure 6). The abdomen is yellow with black bars. While adults are not considered strong flyers, local dispersal occurs at a rate of several kilometers per year.

Adult spotted lanternfly, wings closed
Figure 5. Adult SLF. Source: Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org.
Adult spotted lanternfly, wings open
Figure 6. Adult with hindwings exposed. Source: Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org.

Signs of and symptoms

In addition to the insects themselves, signs and symptoms of SLF include:

  • Plants that ooze and have a fermented odor. Look for weep trails on the trunks of larger trees (Figure 7).
  • Buildup of sticky fluid (honeydew) and sooty mould on plants and on the ground underneath infested plants (Figure 8).
Understory plant with sooty mould
Figure 7. Injury/ooze from spotted lanternfly. Source: Emelie Swackhamer, Penn State University, Bugwood.org.
Understory plant with sooty mould
Figure 8. Understory plant with sooty mould. Source: Emelie Swackhamer, Penn State University, Bugwood.org.

Help reduce the introduction and spread

Long distance spread is typically associated with people inadvertently moving overwintering egg masses. Female SLF lay their eggs on virtually any flat surface, including host plants and non-plant material such as landscaping stones, outdoor furniture, pots, firewood and vehicles. If you have been travelling through known infested areas in the U.S.:

  • Check vehicles, equipment and yard items for SLF before you return to Ontario. SLF hitchhike to new areas on cars, trailers, campers, ATVs, outdoor furniture, toys, pots and recreational gear, all of which should be inspected. Pay particular attention to your vehicle’s underside and wheel wells, noting egg masses can look like mud spatters. Consider going through a high-pressure car wash to remove any potential egg masses.
  • Don’t move firewood. SLF feed and lay eggs on many tree species. Buy firewood close to where you will burn it, to avoid transporting unwanted pests.
Adult and fourth instar nymphs
Figure 9. Adult and fourth instar nymphs. Source: Heather Leach, Michigan State University.

Report your sightings

Spotted lanternfly is a quarantine pest in Canada. If you see a suspected SLF in Ontario, take pictures, collect a sample and report it immediately to the Canadian Food Inspection Agency. Information including location, date and items/plant on which the specimens were found should be included in your submission.

For photographs, a clear image of the specimen is needed for species confirmation. If collecting samples, place eggs, nymphs or adults into a sealed container or plastic bag containing alcohol or vinegar to kill them. Eggs can be scraped into the container or bag with a knife or credit card. Do not transport live specimens.


For more information on SLF, visit the following websites:

Accessible image description

Figure 1. Seasonal biology of spotted lanternfly in Pennsylvania. Source: Invasive Species Centre.

Spotted Lanternfly life cycle
  • 1st to 3rd instars (0.3 to 0.7 cm)
    • 1st instar: May – June
    • 2nd instar: June – July
    • 3rd instar: June – July
  • 4th instar (approximately 1.3 cm): July – September
  • Adult (2 to 3 cm): July – December
  • Egg laying: September – December
    • 2–5 segmented rows
    • 2.5 cm
    • Often, but not always covered
  • Egg masses: December – June