What is Ontario Doing?

To prevent these unwanted invaders from coming into the province, Ontario has regulated the Spotted Lanternfly as prohibited under the Invasive Species Act, 2015.

Background

Spotted lanternfly (SLF) is a planthopper insect that is native to southeastern Asia. It was first discovered in North America in 2014 in Berks County, Pennsylvania, and has since spread to New Jersey, Delaware, Maryland, and many other US states. As it is not yet established in Canada, it was added to the Canadian Food Inspection Agency’s regulated pest list in 2018.  

Adults prefer to feed and lay eggs on the invasive tree-of-heaven (Ailanthus altissima), however SLF poses a significant risk to Ontario’s horticulture and wine industry as nymphs often target grapevines and fruit trees, as well as pines, oaks, and walnuts. It can be easily distinguished from native and naturalized insects based on its unique colouration. Adults and nymphs feed on sap from the leaves and stems of host plants. The excreted sap from the wounds can cause mold or fungal growth on the infested plants and encourage other insects to feed on the plant.

Range

SLF is native to China, Taiwan, and Vietnam. It is considered invasive to Japan, South Korea, and the US. On September 9, 2022, over 100 SLF were found in a residential area of Buffalo, New York. Although they are not yet established in Canada, they are found throughout the northeastern United States. SLF is a high risk of being introduced to Canada through the transport of the adult insect, or the egg masses, which can be quite discrete.  

For an up-to-date range map, consult the Canadian Food Inspection Agency.  

Impacts of Spotted Lanternfly

• Feeding SLF creates weeping wounds on trees and can cause dieback of host plants. 
• SLF threatens fruit, vine, and forestry industries in Canada by reducing yield and quality of fruit. 
• The sugary waste of SLF called “honeydew” accumulates below host trees which can develop black mold that reduces photosynthesis and growth of understory plants. 
• The honeydew can also attract other insects to feed on the tree. 

How to Identify

In the winter, egg masses are produced on smooth surfaces. They are roughly 2.5 cm (0.98 in) long and covered in a grey waxy coating. In the late winter and early spring, egg masses lose their coating, revealing brown eggs. In the spring when nymphs hatch, they are black with white spots and 0.6 cm long. In the early summer, the nymphs become redder as they mature, but they retain white spots. At this time, they can grow up to 1.25 cm (0.49 in) long. In the late summer adults are up to 2.5 cm (about 0.98 in) long, and their front wings are light brown to pink-grey and their rear wings are red. Both sets of wings have black spots near the front. When the forewings are open the bright red underwings become visible. Both nymphs and adults tend to congregate in large numbers.  

What You Can Do

• Learn to identify adult SLF and what infested trees look like, as well as which host trees they target. 
• Inspect your vehicle or other smooth surfaces if you have been to an infected area.
• If you see the SLF, take a photo, catch it, and put it into a container, and contact the CFIA. 
• If you see the SLF or any other invasive species in the wild, please contact the toll-free Invading Species Hotline at 1-800-563-7711, or visit EDDMapS.org to report a sighting.  

Other Resources

• Invasive Species: A Threat to Ontario’s Biodiversity
• Invasive Species Centre
• Forest Gene Conservation Association
• Canadian Food Inspection Agency

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