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.
Butterfly weed, Schenley, 9 August 2023 (photo by Kate St. John)
13 August 2023
The birds are quiet now but the bugs are busy.
After I photographed this butterfly weed (Asclepias tuberosa) I zoomed in to look at the yellow spec on the back edge of the flower cluster and found a tiny yellow crab spider clinging to the flowers. My guess is that he’s a member of the Thomisidae family, lying in wait for something. But what?
Tiny yellow crab spider on butterfly weed, Schenley, 9 August 2023 (photo by Kate St. John)
On Monday, while walking the Three Rivers Heritage Trail River opposite Herrs Island, I noticed a caterpillar on the wide aluminum railing. It reminded me of the hickory tussock moth except that this one was blonde.
Sycamore tussock moth caterpillar near Herrs Island, 7 Aug 2023 (photo by Kate St. John)
iNaturalist identified it as a sycamore tussock moth (Halysidota harrisii). The railing was directly beneath his host plant, a sycamore tree (Platanus occidentalis).
Sycamore leaves and stems, Aug 2023 (photo by Kate St. John)
The caterpillar walked rapidly down the railing in a straight line until Whoa! a spotted lanternfly red nymph walked rapidly toward him. The caterpillar made a detour.
Sycamore tussock moth detours to avoid a spotted lanternfly, 7 Aug 2023 (photo by Kate St. John)
At Frick Park on 6 August we found a lot of millipedes on the paved Nine Mile Run Trail. iNaturalist says they are greenhouse millipedes (Oxidus gracilis), thought to be native to Japan but introduced around the world. They get their name from being a pest in greenhouses.
Greenhouse millipede, Frick Park, 6 Aug 2023 (photo by Kate St. John)
And finally I was fooled yesterday by these mating orange and black bugs, as fooled as they intended me to be. They looked like milkweed bugs, but why were they on a false sunflower?
False milkweed bugs mating on a false sunflower, 11 Aug 2023 (photo by Kate St. John)
Damaged adult spotted lanternfly, Pittsburgh, 22 July 2023 (photo by Kate St. John)
8 August 2023
Aaarrg! They’re everywhere! Pittsburgh is in the midst of a spotted lanternfly (Lycorma delicatula) invasion and it’s just plain creepy. These bugs don’t bite but they’re large, they leap and fly unpredictably, and there are just so many of them. Even when damaged like the one above, they’re disgusting. Make them go away!
So what kills them? I’ve seen a few birds attempting to catch the nymphs but those few birds can hardly make a dent in such an overwhelming insect population.
For now it’s up to humans kill them. Not with poison but by more ingenious means.
DO NOT USE STICKY TAPE. It kills birds and beneficial insects –> Never Use Sticky Tape.
How about robots? Carnegie-Mellon’s Robotics Institute developed a robot that scrubs spotted lanternfly (SLF) egg masses off trees in winter so they can’t hatch the following spring. This is fascinating and useful in the long run for orchards but it doesn’t help us today. (1:29 minute video)
Another long term solution is to introduce SLF’s natural predators. Researchers in Delaware are studying two species of parasitic wasps from China that target spotted lanternflies but it will take years to make sure these tiny wasps are totally dedicated to SLF and will not attack North American species. If these wasps pass the test they’ll provide a long term solution for vineyards. (3:00 minute video)
And then there’s just plain killing them. The second half of this 2022 video shows how a woman in Gillette, NJ kills them in bulk. Favorite tool? An electric “tennis” racket! (Entire video here is 8 mins long. Excerpt is 4:00 minutes)
If you live in southwestern PA and haven’t seen a lot of lanternflies yet, just wait. Butler, Lawrence, Fayette and Somerset Counties were added to the SLF quarantine this year. Forewarned is forearmed … with an electric “tennis” racket!
Water beads on wax begonia, 17 July 2023 (photo by Kate St. John)
22 July 2023
Other than a few thunderstorms it’s been a quiet week in Pittsburgh.
At the Cathedral of Learning the garden beds are beautiful with begonias while the peregrines, Carla and Ecco, hang out and finish molting. The pair is no longer courting but sometimes bow together — less than once a day in late July.
On Thursday I was lucky to find the right mix of sun and shade to show off eastern enchanter’s nightshade’s (Circaea canadensis) bur-like fruits. They are notoriously difficult to photograph.
Enchanter’s nightshade near Herrs Island, Pittsburgh, 20 July 2023 (photo by Kate St. John)
On 13 July a brief storm blew through Pittsburgh and broke this more than 100 year old London plane tree near Carnegie Library.
London plane tree at Carnegie Library of Pittsburgh broken by strong wind on 13 July 2023 (photo by Kate St. John)
Meanwhile spotted lanternfly (SLF) red nymphs are everywhere, soon to become winged adults. I found thousands of them along the Allegheny River Trail near Herrs Island plus three adults, the first I’ve seen this year. This winged adult probably just emerged from the crumpled exoskeleton above it. Eewwww!
Spotted lanternfly adult near red nymphs on the Three Rivers Rowing Association building across from Herrs Island, 20 July 2023 (photo by Kate St. John)
A few people along the trail were stamping on the nymphs and might have been recording their victories in the Squishr app (described here by WHYY). However, as Howard Tobias remarked a few weeks ago, “Tramping on spotted lanternflies is like trying to empty the ocean with a spoon.”
Are you upset by the bugs? Go hit the Panic Button at Carnegie Library of Pittsburgh in the Main branch Music Department, 2nd floor. This Panic Button, built into a bookcase, used to be part of the old security system but was disconnected decades ago. Press it to your heart’s content. Very satisfying.
The Panic Button at Carnegie Library of Pittsburgh (photo by Kate St. John)
And don’t forget to …
Confirm your paperwork? Or throw it in the bin? at Carnegie Museum, Pittsburgh, 19 July 2023 (photo by Kate St. John)
Red nymph stage of the spotted lanternfly, Pittsburgh, 13 July 2023 (photo by Kate St. John)
14 July 2023
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.
