Spotted Lanternfly Getting Too Close for Comfort!

Denise Beaton, Crop Protection Specialist, OMAFRA; Hannah Fraser, Entomologist – Horticulture, OMAFRA

Early Detection is Critical

Keep a watchful eye out for the invasive planthopper, spotted lanternfly (Lycorma delicatula). This voracious sap-feeding insect attacks various crops, landscape ornamentals and hardwood trees. Established populations have NOT been found in Canada (yet) but is moving closer and closer to our Ontario border with recent detections in New York and Michigan.

Early detection of any spotted lanternfly sightings is CRUCIAL so we can act quickly and limit its spread. Report any suspected finds immediately to the Canadian Food Inspection Agency (CFIA) online or by calling 1-800-442-2342.

Distribution

Native to Asia, spotted lanternfly was identified in Pennsylvania in 2014. Despite containment efforts, this pest has spread further and established populations are now found in various regions across the United States.

In September 2020, the CFIA confirmed the identification of two dead spotted lanternflies on commercial trucks travelling from Pennsylvania to Quebec, illustrating the pests’ capacity for being spread quickly over large geographic areas by human activities.

Crops at Risk

There are over 70 documented hosts in North America, including grapevines, fruit trees (apple, peach, plum, cherry), hops and hardwoods (black walnut, maple).

Aggregations (swarms) of nymphs and adults damage plants directly by feeding on plant sap, and indirectly by excreting large amounts of honeydew (sugary waste) that promotes the development of sooty mold and interferes with photosynthesis. The sooty mold also attracts insects such as ants, wasps and bees.

Reports of economic injury in Pennsylvania have occurred in commercial vineyards, where swarm feeding has resulted in yield loss, decreased sugar content in harvested grapes, and weakening and death of vines. For trees, heavy feeding from spotted lanternfly feeding doesn’t usually kill the tree but is a stressor and some dieback can occur.

Be Prepared

The spotted lanternfly is an excellent hitchhiker. Adults can cling to cars moving at high speeds for long distances. Females indiscriminately lay eggs on any smooth surface (vehicles, stones, lawn furniture, etc.); egg masses are difficult to detect, can be moved over great distances, and represent the life stage adapted to overwintering. 

With so many different pathways and potential points of entry, monitoring presents a big challenge. In 2016 and 2018, OMAFRA monitored high risk areas using sticky tree bands. No spotted lanternfly was detected, but it was like looking for a needle in a haystack. Ontario is a big province!  

In 2019, a Spotted Lanternfly Education and Outreach Committee was formed. Members include the Invasive Species Centre, CFIA, OMAFRA, Ontario Federation of Anglers and Hunters, industry representatives and city foresters. Currently, the best plan of attack for Ontario is to have as many trained eyes as possible on the look-out for this unique-looking invasive insect.

Know What to Look For

In the mid-Atlantic states, overwintering egg masses are laid through the fall. The egg masses usually have about 30 to 50 eggs and are laid in parallel lines.

Nymphs begin to appear in the late spring.  They feed and move almost constantly. Keep a close eye on grapes, tree-of-heaven, black walnut, butternut, willow, birch, sumac and roses around your property as nymphs seem to prefer these hosts. Late instar nymphs tend to cluster together on preferred hosts, such as tree-of-heaven and black walnut.

Adults appear mid-July and are active until they are killed by cold temperatures.  In vineyards, adults tend to show up along borders first. There are reports that spotted lanternfly adults are poor flyers; however, they can travel a long distance with the right conditions.

There is one generation of spotted lanternfly per year. Recent observations show that spotted lanternfly does not require tree-of-heaven to survive, but comprehensive information on host use requires additional research.

Management in the United States

In the US, research is being conducted to develop better tools for monitoring and management. You will find the latest information on Penn State Extension’s spotted lanternfly website.

Current management in the US includes:

• Remove and destroy egg masses –Scrape off into a container and place in alcohol (hand sanitizer, rubbing alcohol, other). Check vehicles, farm equipment and other hard surfaced items thoroughly for egg masses if coming from infested areas.
• Remove tree-of heaven – May help reduce numbers but may not be practical if present in large numbers. Herbicides can be applied to control suckers. Since other hosts may prove suitable to complete development, attempts at eradicating tree-of-heaven as a management strategy may prove ineffective. 
• Use sticky tree bands – Helps reduce numbers of nymphs. To avoid catching non-target organisms, use large-gauge mesh over the band, or alternatively, inward-facing sticky bands to intercept nymphs as they climb up host trees. Research to develop better traps is ongoing.
• Encourage natural enemies – This includes spiders, assassin bugs, praying mantis and others that prey on spotted lanternfly. Relying on natural enemies alone may not be enough to control a high population. Parasitic wasps have been identified in China but require evaluation for non-target effects. 
• Use insect-pathogenic fungi – Fungal pathogens, such as Beauveria bassiana, are being evaluated. The entomopathogenic fungus Baktoa major has been found in association with SLF in Pennsylvania and appears to be highly virulent against the pest.
• Apply insecticides – Products containing bifenthrin, thiamethoxam, dinotefuran, carbaryl, fenpropathrin, malathion or zeta-cypermethrin provide effective control of nymphs and adults. Chlorpyrifos is the only active ingredient that gave high mortality of eggs. Mineral oil has shown egg mortality of up to 71%. For landscape trees, they have used tree injections, trunk sprays or soil drenches with certain neonicotinoid insecticides with excellent results. Currently, we do not have any registered uses for the control of spotted lanternfly in Canada; however, the pest has been prioritized through the Minor Use Program for the high-risk crops.