Back in the ‘Burgh from our trip to Cape Cod, the first thing I noticed in my neighborhood was a troop of red nymph spotted lanternflies crawling on walls and sidewalks near an ailanthus tree — their host tree, a.k.a Tree of Heaven.
Red nymphs are the fourth and final instar in spotted lanternfly development.
They’re here, they’re creepy and they’re not going away any time soon. Spotted lanternflies (Lycorma delicatula) have made it to Pittsburgh and are following the typical trajectory of invasive insect pests: Barely noticeable (2018) to Overwhelming (2022, 2023+) to Hard to Find (declines in about 3 years: 2025).
The most important thing to remember is this from Penn State Extension: Avoid overreacting to the situation and teach others not to overreact. Insecticides won’t eradicate the pests but will kill the good bugs, bees and butterflies. Instead, let’s outsmart spotted lanternflies.
First, know the enemy and its weakness: Spotted lanternflies can only crawl up, they can’t reverse!
Third, protect a favorite tree using this circle trap (video below). You can make your own circle trap or buy one here. Do not use sticky tape as it traps and kills birds (trying to eat the bugs) and beneficial insects.
Fourth, be brave. Yesterday Claire Staples outsmarted hundreds of spotted lanternfly nymphs by smashing them with her bare hands! Here are her photos and a quote from her email. (How many nymphs can you see in the right hand photo?)
I killed over 200 in a 10 foot section along the power lines through Swisshelm Park slag heap. It was the only place where we found them but it was amazing to see the density. It was really easy to get them and my granddaughter watched and only a few escaped. I would take the small branch with the bugs in the palm of my hand and place the other palm on [top of] it and start rolling my hands together. I was amazed that my hands appeared clean and there was no odor. I did wash my hands later but I was surprised that there was no residue.
— email from Claire Staples, 11 June 2023
That’s braver than I would have been!
Meanwhile, the lanternfly population will eventually decline on its own. Here’s what happened in Berks County, PA where spotted lanternflies were first discovered:
2014: Barely noticeable. Spotted lanternfly first discovered in U.S.in Berks.
2018, 2019: Overwhelming. Everywhere! Some commercial grapevines killed.
If you noticed spotted lanternflies (Lycorma delicatula) in Pittsburgh last summer you remember seeing this one-inch long insect.
But they don’t start out this big.
Right now they are tiny black nymphs with white spots. I saw one perched on the edge of a metal chair yesterday at the Phipps BioBlitz and moved closer to confirm its identity. As I approached it jumped so far I couldn’t find it.
I tracked it down and smashed it with my shoe … and immediately wished I’d taken its picture. I found another one (there are lots of them) and learned how to get close enough for a cellphone photograph without making it jump. Not a sharp photo but you get the idea.
The first instar(*) nymphs are tiny — just 1/4 inch long — and well camouflaged, even on a silver chair.
As they feed on plants the insects grow and change through various stages of development. The first, second and third instars continue to be black nymphs with white spots, just progressively larger [B]. The fourth instar is a red nymph with white spots at 3/4 inch long [C].
Right now they’re so small they are easy to overlook. When the one-inch-long flying adults emerge in July-to-September this invasive insect will be hard to ignore.
Ever since spotted lanternflies (Lycorma delicatula) made their disgusting appearance this July in Pittsburgh we’ve been crushing and smashing them, but it’s clear that we humans can barely make a dent in the population. Most of the bugs fly way above our heads and land high in the trees. We can’t reach them but someone else can.
Spotted lanternflies are completely new to North America’s native species, but the bugs look like food so Nature is stepping in to eat them. Predation results are far more successful than our smashing.
UPDATE 18 Sep 2022, this post has attracted many new readers & commenters and has prompted this NOTE TO COMMENTERS –> Comments on this blog are moderated. If you post a comment that is profane or could inflame others, I will edit it or delete it.
(photos from Wikimedia Commons and iNaturalist; click on the captions to see the originals)
Frank Izaguirre’s experience in Oakland is typical. The first one appeared on 17 July but within ten days the number of bugs had grown so fast that finding and killing them, as recommended by the PA Dept of Agriculture(*), became a daunting daily chore.
Annie Quinn noticed them in a park and enlisting her kids to squash them on the ground. Then she looked up and saw hundreds and hundreds coating the upper branches of the trees. “Kids, this problem is much bigger than we are.”
Indeed! I saw hundreds (thousands?) on the North Shore near the Carnegie Science Center on Tuesday 26 July.
And it’s going to get worse before it gets better.
Julie Urban, an associate professor of entomology at Penn State, said residents of the area will see a lot more lanternflies in September.
“They’re starting to emerge as adults about now and then when they start to mate more heavily you’re going to see a lot more in the first couple weeks of September,” said Urban. “That’s just when they’re more active. So, be ready for that.”
Since each female lanternfly lays an egg mass containing 30-50 eggs, the population grows exponentially every year: 1 > 50 > 2,500 > 125,000 > 6.2 million!
It took just 2.5 years to go from “What’s the problem?” to “Oh my gosh!”
There is no way we can squash them individually. However there are easy ways to passively kill them in our yards. Three years ago a girl in New Jersey came up with a very inexpensive and effective trap.
When the invasive spotted lanternfly (Lycorma delicatula) was first discovered near Allentown, Pennsylvania in 2014, biologists and farmers worried that it would destroy agriculture and kill native trees. Now that the insect has been in North America for seven years and shown what it can do, scientists have their revised their advice about this bug.
Back in 2014 we had no experience with spotted lanternfly so we looked to another place where it is invasive — South Korea — and applied their experience to our landscape. The forecast was bad, the prognosis dire.
Fortunately the bug didn’t do what we thought it would. The only tree it kills is its host tree, tree-of-heaven (Ailanthus altissima), one of the worst invasive plants in North America.
Spotted lanternflies can stress native trees, especially young ones, but they don’t kill them.
As for agriculture spotted lanternfly nymphs kill grapevines, below, but not other fruits and vegetables. This spares most of Pennsylvania’s farmers.
The Allegheny Front reported in February that the widest economic impact is felt by businesses that must inspect everything before they transport goods — and potential lanternflies — from quarantined to non-infected locations.
Knowing they are vulnerable, stinkbugs take shelter in the fall by burrowing into the cracks of our homes. Aaarrg!
Spotted lanternfly adults die in winter but that’s no problem for this invasive insect. Before they die the females lay eggs to overwinter as the next generation.
According to Wikipedia, research last year at The State University of New Jersey suggests that -13oF is about the temperature at which all eggs die. At 5oF there is limited hatching but it depends on how long they were chilled and where they were kept. Pittsburgh has merely flirted with 0oF this winter, not enough to kill lanternfly eggs.
Fall is breeding time for spotted lanternflies which are now in their winged adult phase. The adults won’t survive the winter but their egg masses will, so the more adults we eliminate now before they lay eggs the better.
Smashing a spotted lanternfly is easier said than done. The bugs have instant reflexes and jump when approached. However you can catch them in a water bottle. Easily! That’s why this video went viral.
Save a couple of plastic water bottles and lids. You’ll need lids to keep the bugs in the bottle.
Catch the bugs early in the day before they go too far up the trees.
Freeze the bottles containing lanternflies. The bugs die when they’re cold. Ta dah.
p.s. UPDATE, 5 November 2021: I saw my first spotted lanternfly in Schenley Park. It was in the SLF trap near the Bartlett tufa bridge.
(photos from Wikimedia Commons, Bugwood and Kate St. John; videos embeded from YouTube)
Just a reminder that with Bug Season in full swing you may encounter this dangerously invasive pest, the spotted lanternfly (Lycorma delicatula) that sucks the sap out of grapes, fruit trees, oaks, black cherries and its favorite the invasive Ailanthus or Tree of heaven.
Spotted lanternflies (Lycorma delicatula) are invasive planthoppers native to China and Vietnam whose favorite food is the invasive Ailanthus, the Tree-of-Heaven. If they ate only Ailanthus it would be OK but their sharp mouth parts pierce the stems and suck the sap of grapevines, hops, apple trees, peaches and hardwoods including oaks and cherries. They’re bad news for agriculture and forests.
Lanternflies are making quick progress across Pennsylvania because they’re aided by human transportation. First discovered in North America in Berks County, PA in 2018 the bug spread through eastern PA for two years. In early 2020 it was found on rail cars at the Norfolk Southern railyard in Conway, Beaver County. Soon after in Allegheny County. Early this year it completed an unbroken path through the lower third of the state by adding Westmoreland and Cambria Counties. What’s on this path? The Norfolk-Southern Railroad.
The lanternfly travels easily from September to May as flat gray egg masses on rail cars, trucks and automobiles.
Adult near egg masses: New = mud in foreground, Exposed = lumpy in background (photo by Lawrence Barringer, PA Dept of Agriculture, Bugwood.org)
Egg masses on a rusty barrel (photo by Lawrence Barringer, PA Dept of Agriculture, Bugwood.org)
A few egg masses on a tree (PA Dept of Agriculture, Bugwood.org)
Egg masses on the back of a bench (Emelie Swackhamer, Penn State University, Bugwood.org)
Egg masses on a birch in winter (Emelie Swackhamer, Penn State University, Bugwood.org)
Final instar under a car (Lawrence Barringer, PA Dept of Agriculture, Bugwood.org)
The eggs hatch from spring through summer so now’s the time to watch for black or red spotted nymphs, especially in the unmarked counties above.