Eastern bottlebrush grass (Elymus hystrix) with tiny spider threads.
Pavement glowing in the sun? No, pond scum on Panther Hollow Lake.
Dead adult spotted lanternfly nose-down with legs flexed open. Shadyside, 18 July.
Oh deer … Details near their photos.
Feverfew, Schenley Park, 19 July 2024 (photo by Kate St. John)Eastern bottlebrush grass with tiny spider webs, Schenley Park, 19 July 2024 (photo by Kate St. John)The surface of Panther Hollow Lake, Schenley Park 19 July 2024 (photo by Kate St. John)
Dead adult spotted lanternfly, Shadyside in Pittsburgh, 18 July 2024 (photo by Kate St. John)
Oh deer. Yesterday I saw four deer in Schenley Park; three in this family. The two spotted fawns appear to be a month younger than this year’s cohort that were born in May. If so, it was because their mother bred later than the rest of the herd, perhaps because she was a fawn herself last year.
One-year-old mother (probably) with two spotted fawns, Schenley Park, 19 July 2024 (photo by Kate St. John)
In the photo above, notice how little food there is on the ground. Without much to eat, deer in Schenley Park browse on foods they don’t like, such as the Japanese knotweed below.
Japanese knotweed browsed by deer, Schenley Park, 28 June 2024 (photo by Kate St. John)
Neighborhood gardens have a lot more food, so guess where the deer go. Last month I saw two in a garden with plants up to their shoulders. Not for long, though. As I watched one of them opened its mouth to take a large bite.
Deer eating in a garden on Ellsworth Ave, Pittsburgh, 17 June 2024 (photo by Kate St. John)
John English saw this spotted lanternfly adult outside his window on 17 July 2024
18 July 2024
They’re back. Well, actually, they never left but they haven’t looked like this since last fall. Up until now spotted lanternflies (Lycorma delicatula) in western Pennsylvania have been present as egg masses or nymphs.
Yesterday a winged adult lanternfly landed on John English’s window feeder in Homestead. This is the first report I’ve received that adults have emerged.
Their population will follow a well known arc. A smattering in mid July, lots more in August, an invasion in September.
Have you seen an adult spotted lanternfly yet? Leave a comment and let me know when you saw the first one.
p.s. I just got back from a week in Virginia where I learned that spotted lanternflies are indeed in Virginia wine country. They are really bad for grapes. Yikes! Here’s the 2024 map from New York State Integrated Pest Management and Cornell University.
Last instar of the spotted lanternfly, Pittsburgh 14 July 2023 (photo by Kate St. John)
2 July 2024
In late June friends of mine wondered why they hadn’t seen any spotted lanternflies this year. Are the invasive bugs gone? Not at all! The nymphs are present but they can’t fly yet. Last weekend I saw the first warning that we’re in the last days — a week, maybe two — before the spotted lanternfly invasion begins. I saw a red nymph.
Spotted lanternfly red nymph, Schenley Park, 30 June 2024 (photo by Kate St. John)
The first three instars are black while the fourth and final one is red, an early warning of things to come. Here’s a red nymph morphing into a winged adult.
Expect to see the first flying adult by mid-July. Let me know when you see your first one.
The invasion will ramp up slowly, explode in September, and then we’ll have to wait for winter to kill them.
p.s. It’s been 10 years since spotted lanternflies were first recorded in PA. Now the bugs are in every county in southern PA and all of the eastern border counties. Greene County, the last holdout in southwestern PA, crossed the threshold this year. Read more about their 10-year siege in this article from WESA.
When we think of spotted lanternflies we remember the flying adults that plague us from July through early autumn. But these annoying insects don’t start out in flying form.
In May-June their eggs hatch into tiny black nymphs, 1/4″ long, with white spots. If the nymph manages to pass through four instars it becomes a winged adult.
Black nymph spotted lanternfly at Phipps on 4 June 2023 (photo by Kate St. John)
On Monday 3 June, Bob Donnan saw a couple of the black-spotted early nymphs in Washington County, PA. Oh no! They’re already here. The tiny nymphs are hatching.
Smashing them doesn’t work. As Bob remarked, “They jump fast!”
Check out last year’s article on alternatives for trapping spotted lanternflies.
Sticky tape put on trees by an unknown Frick Park visitor, 19 Sept 2023 (photo by Michelle Kienholz)
20 September 2023
Six years ago, when spotted lanternflies (Lycorma delicatula) were a new plague in North America, no one knew if they would destroy Pennsylvania’s forests but scientists assumed the worst and warned accordingly. However, they also conducted long term studies of spotted lanternflies’ effect on Pennsylvania trees and agriculture. For PA trees there is happy news: Spotted lanternflies are not a danger to Pennsylvania forests. There’s no need to protect our trees from lanternflies because they are not hurting them.
Penn State subjected four species of trees to four years of spotted lanternfly super-infestation by surrounding the trees with mesh nets that kept hordes of lanternflies inside. Silver maple, weeping willow, and river birch were barely phased by the bugs and did quite well in the third year of the study. The bugs’ host plant, the invasive tree of heaven (Ailanthus altissima), did not grow during the plague.
“If you have a vineyard and you have lanternflies on your grape vines, you should be very worried because they can kill grape vines,” Hoover said. “But if you’re a homeowner and you have large trees on your property and you have lanternflies on them, I don’t think you should worry about it.”
Yesterday an unknown visitor to Frick Park put sticky tape on some trees. Here’s what one section killed: 12 spotted lanternflies, 25+ pollinators (yellowjackets), 70 warbler-food insects (tiny flying insects). More beneficial insects died than lanternflies. Needless to say the tape has already been removed. (Click here to see how sticky tape kills birds!)
Sticky tape deaths in Frick Park, 19 Sep 2023 (photo by Michelle Kienholz)
Sticky tape is bad and pointless. If you put it up, remove it.
Sooty and white mold grow on honeydew deposited by spotted lanternflies feeding on Ailanthus, Schenley Park, 15 Sep 2023 (photo by Kate St. John)
17 September 2023
The onslaught of invasive spotted lanternflies (Lycorma delicatula) continues in Pittsburgh until the first truly cold weather gives us a couple of frosts. This month the bugs are congregating on vertical objects, feeding on Tree of Heaven (Ailanthus altissima), and laying eggs.
On Friday in Schenley Park the sun broke sideways through the trees to a large Ailanthus along the Lower Trail coated in lanternflies, sooty mold, and white mold (highlighted in yellow). The lanternflies were actively sucking on the tree’s sap.
White mold on Ailanthus beneath the spotted lanternfly feeding zone, Schenley Park, 15 Sep 2023 (photo by Kate St. John)
Sunlight illuminated small bugs flying horizontally near the tree and something falling that looked like rain.
Spotted lanternfly honeydew drops like rain, Schenley Park, 15 Sep 2023 (photo by Kate St. John)
Uh oh! That rain is watery spotted lanternfly poop called “honeydew.” The honeydew is sugary and the air actually smelled sweet.
So stand back when you see a tree coated in sooty mold and spotted lanternflies. You won’t want to get rained on.
Dead spotted lanternfly at the base of a utility pole, 13 Sept 2023 (photo by Kate St. John)
13 September 2023
They aren’t very smart but they know what they like: warmth and vertical objects.
If you haven’t been to Downtown or Oakland lately you’re missing an insect phenomenon. Our plague of spotted lanternflies (Lycorma delicatula) is quite attracted to tall buildings and utility poles, especially when it’s hot.
Spotted lanternflies love this utility pole when the sun heats it (photo by Kate St. John)
Like moths to a flame, spotted lanternflies are visually drawn toward and seemingly captivated by vertical objects such as utility poles …
[They] turn and land on the poles when they are less than about 10 feet away. They remain on the pole for many minutes, even hours, while crawling up toward the top to try to take flight again.
However, a large proportion of those launching themselves from the pole are drawn back to the pole, which serves as a sort of “visual magnet” from which the insects cannot escape for a while.
On hot days I see thousands above me, puttering toward the buildings, tapping along the structures as they try to find a place to land.
This building is especially attractive to spotted lanternflies, Sept 2023 (photo by Kate St. John)
The bugs cling and fall off, leaving drifts of lanternfly carcasses on the ground below.
Spotted lanternflies litter the base of the Rand Building, 11 Sept 2023 (photo by Kate St. John)
There’s a theory that the bugs like vertical objects because they are such weak fliers that they have to climb up and relaunch on their search for their host tree, the Tree of Heaven (Ailanthus altissima). According to Penn State Extension, they “land on buildings for warmth, height and other unknown reasons.” Other unknown reasons: Who can know the mind of a lanternfly?
Fortunately we can learn from Philadelphia where their spotted lanternfly plague hit in 2020 (during the pandemic). Here’s what happened at a taco shop on the ground floor of a high rise.
Note that Philadelphia had their lanternfly plague in 2020 and now, three years later, they are wondering where all the bugs have gone. I’m sure we can expect 2-3 summers of this nonsense. Certainly by 2026 spotted lanternflies will just be a bad memory in Pittsburgh.
Spotted lanternfly honeydew below ailanthus tree turns black with sooty mold, Schenley, 25 Aug 2023 (photo by Kate St. John)
27 August 2023
In Schenley Park’s Panther Hollow there are only a handful of Ailanthus altissima trees (Tree of Heaven) which I rarely paid attention to until recently. A couple of weeks ago I noticed that the plants and ground beneath those trees were wet, though it had not rained. This week the leaves and ground are black. Both phenomena are a by-product of the spotted lanternfly (Lycorma delicatula) invasion.
Spotted lanternflies (Lycorma delicatula) are sucking insects that pierce the bark of their host plant, Ailanthus, and sip the sugary phloem that travels from the leaves to the rest of the plant. (Phloem flow is orange in the diagram below.)
If there were only a few lanternflies we would never notice the honeydew but when a large number coat a tree the honeydew is hard to miss, especially for the consumers of honeydew: bees, wasps, hornets, ants and butterflies.
Sugary honeydew eventually grows sooty mold. Everything with honeydew on it turns black.
Sooty mold is a fungus that appears as a black, sooty growth on leaves, branches and, sometimes, fruits. It is non-parasitic and not particularly harmful to plants apart from being unsightly. Potentially, it could affect the plant’s ability to use the sun for photosynthesis. If you can rub the black growth off with your fingers, it is probably sooty mold. If you cannot rub it off, it is most likely something else.
Spotted lanternflies land to roost just before sunset, Pittsburgh, 22 August 2023 (photo by Kate St. John)
24 August 2023
Spotted lanternflies (Lycorma delicatula) are everywhere in the East End of Pittsburgh and along our rivers and railroads. One even triggered a snapshot on the motion detection camera at the Pitt peregrine nest. Aaarrg!
Spotted lanternfly perched on the National Aviary snapshot falconcam at Univ of Pittsburgh
Right now, while the invasion is getting worse by the day, it is hard to imagine a time without them but that day will come. The bugs have daily, seasonal and annual cycles and their population trend goes down, based on what happened in eastern PA where they were first detected. Let’s take a look.
Daily dispersal, nightly roost. During the day adult lanternflies disperse to the sky but at dusk they land on buildings and trees to “roost” overnight. Dusk is an unpleasant time of day as they aggregate near us but it’s a good opportunity to catch them with a water bottle (video shows how). [Put a lid on the bottle and the bottle in the freezer. They die in the cold.]
Seasonal disappearance of adults in late fall. Spotted lanternfly adults mate and lay eggs in late summer and fall. Winged adults started to appear in July in Pittsburgh but they did not reach a crescendo until mid-August. They’ll be present in September and October and completely die off at the first frost. I expect their presence to taper before they disappear.
I have not been able to find out if the individuals die shortly after mating and laying eggs but if so the population would taper quickly. I’ll know more in November.
Invasion lasts two to three years based on experience in Eastern PA.
Lanternflies were a plague in Berks County(*) in 2018 and 2019 but by 2021 they were hard to find. That year the Reading Eagle wrote “Where have all the spotted lanternflies gone?“
Notice that Philadelphia is saying “IF you see spotted lanternflies,” not “WHEN you see spotted lanternflies!”
Based on these reports I’d say the infestation lasts two to three years and then drops to an unremarkable level. It seems to be a bell curve.
Spotted lanternfly invasion appears to be a bell curve with maximum at 2-3 years (guesstimate by Kate St. John)
The Pittsburgh area has had spotted lanternflies since 2020. This summer we are in the first plague year (Year label 5). Next summer will be bad, too, but by 2025 or 2026 they’ll be virtually gone.
This, too, shall pass.
p.s. Great News! Two naturally occurring native fungi infect and kill spotted lanternflies in great numbers. Batkoa major and Beauveria bassiana decimated the spotted lanternfly (Lycorma delicatula) populations near Reading, Pennsylvania in 2019. Fingers crossed!
(*) Berks County in 2014 is the location where spotted lanternflies were first identified in the U.S.
(photo by Kate St. John and from the National Aviary snapshot camera at Univ. of Pittsburgh, graph by Kate St. John)
Invasive spotted lanternflies are swarming over Pittsburgh right now, especially near the railroad tracks. Everyone wants to kill them but the first solution that comes up on any Google search is a very, very bad one. NEVER EVER use sticky tape to capture insects. Glue tape kills birds!
Raven Ridge Wildlife Center in Lancaster County, PA has years of experience with the harm caused by glue tape. This Facebook report from 17 August 2023 is just one of them. Three of the four trapped woodpeckers died and the fourth is in trouble.
Spotted lanternfly and insect vinegar trap (photo by John English)
Straight white vinegar plus dish liquid — maybe a 1/2 tsp — to break the surface tension. (Insect by-catch in this photo: a cicada.) Thanks to John English for this suggestion.
For personal combat there are lots of solutions: Electric “Tennis Racket” bug zappers, the Bug a Salt Gun, etc. found via Amazon searches.
