Now is the time to tackle pesky pest’s egg masses before they hatch
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| Fall and winter are the times to tackle lanternfly egg masses before they hatch. (URI Photo / Biocontrol Lab) |
The spotted lanternfly was spotted everywhere in southern New England this summer, alighting on mailboxes, plants, decks, cars — and numerous social media feeds. If you thought they were everywhere, you were not imagining it.
Although easily spotted for their colorful aspect in summer,
this invasive insect is a master of disguise at this time of year, laying its
easily missed egg masses to build next year’s bug brood.
But researchers in the University of Rhode Island’s Biocontrol Lab are offering
suggestions of ways to stop the spotted lanternfly in its tracks before it
hatches. As a bonus, tackling an egg mass is easier than snagging the lively
planthopper.
“Management of the eggs is our best bet,” said entomologist Lisa Tewksbury, lab director, “because then you have less feeding from nymphs and adults in the spring and summer season.”
She’s joined by research assistant Dana Terrill ’22, part of
a team at URI studying ways to deploy biological control of species, which can
put agriculture at risk. URI’s Biocontrol Lab conducts research to reduce
populations of invasive species and is one of seven USDA-approved sites in the
U.S. assisting with spotted lanternfly biocontrol research.
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| The adult spotted lanternfly is easy to spot. (URI Photos / Dana Terrill) |
Why did Rhode Island see so many lanternflies this summer
and what does it mean for our local agriculture this fall?
Spotted lanternflies have been found in all five counties in Rhode Island and populations were abundant throughout the summer. Populations are increasing due to their continued establishment and expansion, as well as their ability to be readily transported by cars, equipment, and other materials.
The preferred host of spotted lanternfly is the invasive Tree of
Heaven, but the spotted lanternfly also threatens Rhode Island’s vineyards and
orchards.
Spotted lanternfly adult females lay egg masses between September and December or up until the first or second hard freeze when all adults will die for the season. Egg masses will remain dormant throughout the winter and hatch in the spring.
Before the egg masses hatch in May through June, the best way to get ahead of the new emerging generation is to find and destroy the overwintering egg masses by squishing them to kill the eggs or to scrape them into a container with rubbing alcohol or hand sanitizer using a hard, flat edge.
If you want more thorough control of the tree than scraping
can accomplish, you can use horticultural oil on egg masses during the dormant
season (February to April is the best time to do this) or contact a pest
management professional to make the application for you.
What do the lanternfly egg masses look like?
Overwintering egg masses are the only stage to survive the winter as they have a mud-like substance that covers them, which protects them from predation, desiccation and cold temperatures. They usually resemble a smear of gray or brown mud, typically about one inch long; sometimes over the winter, egg masses may lose the pasty covering and the eggs may be more exposed. Egg masses are mostly deposited on the bark of trees, but can be deposited on any outdoor material, such as underneath cars, fence posts, and even outdoor furniture.
When egg masses are found, the best way to destroy them
is to scrape and squish. The only egg masses that look a bit similar to the
spotted lanternfly egg masses are those of the gypsy, or spongy, moth (although
they are tan in color). Spongy moth is another invasive pest, so accidentally
squishing them instead would not be a problem.
What should people do if they see clusters of
lanternflies on trees during the warmer months and why is chopping down trees
with spotted lanternflies on them not advised?
It is not advised to chop down trees that have spotted
lanternfly on them because often spotted lanternfly populations can shift
locations as they can swarm within a local area and aggregate on other trees,
searching for preferred food sources. Mechanical management options useful in
reducing high numbers of spotted lanternfly include using a handheld or
backpack rechargeable shop vacuum, or using traps such as circle traps that are
good options for funneling and capturing nymphs and adults as they climb up
trees.
What else can we do to tackle spotted lanternfly in our
area and what else is URI’s Biocontrol Lab doing about this insect situation?
The USDA is working to evaluate the use of a biocontrol
agent, a parasitoid wasp that could be implemented as a biological control
program against spotted lanternfly, but this could take a few more years. In
the meantime, there are many natural predators against spotted lanternflies,
such as birds and praying mantids.
Visit the URI Biocontrol Lab website for
advice and information on spotted lanternfly and other pests. Follow @uri_biocontrol
on social media for updates.
