Though the number of adult spotted lanternflies (Lycorma delicatula) is growing this month in Pittsburgh, their population does not match the invasion we saw a year ago. Among the many reasons for this happy news is that local bugs are eating them.
On Wednesday Kalehism Kheshgi found a small praying mantis eating a spotted lanternfly on Carnegie Mellon’s campus.
video by Kaleem Kheshgi, Pittsburgh, 2024-08-14
Several species of praying mantids were imported for pest control: Green ones are from Europe, brown ones are from China. If the brown mantids have deep ancestral knowledge, they will recognize the lanternfly as food from home. 😉
Spiders, yellowjackets, wheel bugs and birds (including northern cardinals!) all eat spotted lanternflies. For photos of the devouring, see this 2022 article.
If you aren’t already avoiding black-legged ticks (Ixodes scapularis) because of Lyme disease, yesterday’s announcement is another reason to be very careful.
The Allegheny County Health Department has announced that the first human case of Powassan virus disease has been detected in the area. It’s the first time the tick-borne virus has been seen in the county, and the first case in the state this year.
Powassan is a rare, but growing, disease that can only be caught from a black-legged tick bite. Initial symptoms can include fever, headache, vomiting, and weakness but it can also cause severe illness including inflammation of the brain (encephalitis) or the membranes around the brain and spinal cord (meningitis). This can result in long term neurological effects.
There is no treatment for Powassan and no vaccine. All that can be done is to wait for it to run its course and mitigate the symptoms.
#1. Check your body for ticks after you’ve been outdoors. There may be ticks in your own backyard so check every time.
How to do a tick check (image from PA Dept of Health & CDC.gov)
#2 Keep ticks off your clothes and skin. Wear long pants and long sleeves and spray your clothes with permethrin. Some suggest using DEET on your skin (if you wear shorts) but I can attest that long pants sprayed with permethrin is much better.
It’s Spray Your Clothes Day (photo by Kate St. John)
Two weeks ago you may have seen videos on the Internet of a giant swarm of dragonflies at a Rhode Island beach on 27 July. The swarms at Westerly and South Kingstown were thankfully brief.
Entomologists identified the bugs as blue dashers (Pachydiplax longipennis) which spend their lives at quiet freshwater ponds and marshes but will swarm to seek out new ponds when their population is high. The 27 July bugs were on the move to somewhere else.
Blue dashers are common in the U.S. and are expanding into southern Canada. The males are gorgeous blue with green eyes, while the females and young males are black and yellow.
Bug Season continues this month as caterpillars pupate into adult moths and butterflies. What species have we found? The first step is to decide: Is it a moth or a butterfly? Clues include:
Antennae: Feathers vs Knobs
Flying: Night vs Day
Wing Position At Rest.
To make matters more complicated, skippers are considered butterflies but they break the butterfly Wings At Rest rule.
Zabulon skipper on my thumb, 12 August 2021 (photo by Kate St. John)
For simple pointers to use in the field, check out this vintage article:.
(*) Details about the top photo: According to Wikimedia, the tussock moths Halysidota tessellaris (banded tussock moth) and Halysidota harrisii (sycamore tussock moth) cannot be told apart in the east by a photo.
Spotted lanternflies along the Three Rivers Heritage Trail, Herr’s Island backchannel, 3 Aug 2024 (photo by Kate St. John)
7 August 2024
Spotted lanternflies (SLF, Lycorma delicatula) were a plague in Pittsburgh last year. This month their adult population is ramping up again. What’s their status now and how do their numbers compare to last summer?
I didn’t pay attention to the first adult spotted lanternfly in 2023 but this year I was ready. My first 2024 sighting was on 18 July. Interestingly I haven’t seen a whole lot of red nymphs and adults compared to last year so I went to a place that was swamped with them in 2023.
On Saturday I visited the Three Rivers Heritage Trail at Herrs Island back channel, a place that was overrun by red nymphs in late July 2023 and had so many winged adults in August and September last year that it was impossible for cyclists and pedestrians to avoid them. The bugs flew into us. It was creepy.
This year on 3 August I found adult lanternflies at the same place but not in an overwhelming number. I counted 16 red nymphs and 68 adults at the most densely populated location. The fact that they were countable is a sign there weren’t that many … yet.
This one tried to avoid being counted. Hah!
Adult spotted lanternfly tries to hide from me at Herrs Island backchannel, 3 August 2024 (photo by Kate St. John)
What I couldn’t count were the bugs above my head sucking sap from invasive vines and ailanthus trees. Their “honeydew” coated the leaves below and “rained” on me at one point. Yuk.
Spotted lanternfly “honeydew” on Virginia creeper leaves below ailanthus trees, 3 August 2024 (photo by Kate St. John)
Last year the worst of the invasion ran from late August to mid September so we still have more to come. Will it be as bad as last year? CBS Pittsburgh provides some expert opinions.
This week Donna Foyle and Betty Rowland both found black swallowtail caterpillars (Papilio polyxenes) on host plants in their gardens. Donna Foyle’s are on parsley. Betty Rowland’s are on fennel.
Two black swallowtail caterpillars on fennel, 1 August 2024 (photo by Betty Rowland)
This success prompted a lively discussion of next steps.
#1. Birds, insects and spiders prey on black swallowtail caterpillars so the first step is to protect them. Birds are easy to exclude. Betty Rowland put a butterfly shelter over her fennel.
Shelter to protect the caterpillars from predation, 2 August 2024 (photo by Betty Rowland)
#2 What if the caterpillers eat all your host plants? Where can you get more? Well, don’t buy greens for your caterpillars! You can’t be sure they haven’t been treated with chemicals. Donna Foyle will look for Queen Anne’s (not near a road) if it she runs out of home-grown parsley.
Black swallowtail caterpillar on home-grown parsley, 2 August 2024 (photo by Donna Foyle)
When the caterpillar is ready to pupate it develops a somewhat camouflaged chrysalis, two examples shown below. (The brown one was photographed in Pittsburgh by Scott Detwiler.)
Variability of black swallowtail chrysalis color: brown and green-gold (photos from Wikimedia Commons)
As adults, black swallowtails are sexually dimorphic …
The Papilio polyxenes demonstrates polyandry and a lek mating system, showing no male parental care and display sites. Females are therefore able to choose males based on these sites and males are the only resource the females find at these sites.
Monarch butterfly on swamp milkweed, 27 July 2014 (photo by Steve Gosser)
31 July 2024
Have you seen any monarch butterflies this summer?
Twenty years ago this question would have been absurd in late July, but this year nature observers are worried that they have seen only one monarch butterfly so far … or none at all. There are two reasons why monarchs are scarce. One is the symptom, the other is the cause.
The Symptom:According to World Wildlife Fund, last winter’s annual survey of monarch butterflies on their wintering grounds in Mexico found that “the species occupied only 2.2 acres during the 2023-2024 winter season — 59% less than the previous year when scientists observed 5.5 acres.” There are 59% fewer monarchs this year compared to last. UPDATE: See Christine Rickabaugh’s comment below with the backstory on what’s happening in Mexico.
The Cause: Since the 2010’s biologists have warned that we are experiencing an Insect Apocalpyse. They have declined an alarming 75% in the past 50 years. The reasons for decline have been hard to tease out because there are so many factors at work.
Fortunately scientists at Michigan State University conducted a comprehensive study on the effect of herbicides and insecticides on insects, and especially on monarch butterflies (Danaus plexippus), in the Midwest. Published last month in PLOS One the study collected recent and historical data from Wisconsin, Michigan, Iowa, Illinois, Indiana and Ohio. MSU Today describes the findings.
While habitat loss, climate change and pesticides have all been implicated as potential causes for the declining insect abundances being observed globally, this work was the first comprehensive long-term study to evaluate their relative effects. Using 17 years of land use, climate, multiple classes of pesticides and butterfly survey data across 81 counties in five states, the researchers found that shifts in insecticide use toward neonicotinoid-treated seeds are associated with an 8% decline in butterfly species diversity across the American Midwest.
These findings include the decline of the migratory monarch butterfly, which has been a prominent concern. Specifically, it is noted that insecticides rather than herbicides are the strongest pesticide factor associated with monarch declines.
Neonicotinoids are so deadly to insects because they are so pervasive. Applied to the soil or as a seed coating, they migrate into the soil, the plant, its pollen, the water table and the air. This diagram shows the transport of neonics as red dots. They are everywhere.
The biggest danger comes from agricultural use. In 2017 the percentage of soy and corn planted with neonic seed coatings (colors below) was high. Now it’s even more.
Neonicotinoids are so effective that they create places without insects. These biological wastelands are missing everything that depends on insects, all the way up the food chain. This cornfield is a wasteland. There are no bugs and no birds here.
And the sneaky part is that you may be putting neonics on your grass or in your garden without realizing it. If you (or your lawn care company) sprays your grass it may well contain neonics. The potting soil and plants you buy at the store are probably treated with neonics before you buy them. Suddenly your lawn and garden are deadly to the butterflies and bees you’re trying to attract. Read more about it in the PDF linked below (or here).
It is going to take a concerted effort from all of us to remove neonicotinoids from our environment and stop the decline of insects. The best time to begin is right now.
Chickory opening slowly as the sun gets higher, Frick, 28 July 2024 (photo by Kate St. John)
29 July 2024
Yesterday there were just four of us on the walk at Lower Frick Park. Charity Kheshgi took the picture so she’s not in it.
Small group at the Frick Park outing at Commercial Street, 28 July 2024 (photo by Charity Kheshgi)
Of all the things we saw, a surprising number of them were blue. Chickory was just opening in the morning sun. We saw and heard two indigo buntings.
Indigo bunting still singing at Frick Park, 28 July 2024 (photo by Charity Kheshgi)
Ebony jewelwing damselflies were courting above the creek. The female jewelwings looked blueish.
Ebony jewelwing, female, Frick Park, 28 July 2024 (photo by Charity Kheshgi)
The males glowed iridescent emerald green.
Male ebony jewelwing, Frick, 28 July 2024 (photo by John Dzikiy)
Best Insect Experiment:
On the way upstream I found two funnel spider webs hiding behind the boardwalk railing. Not a great picture but it shows the hole where the spider is hiding. I have never been able to fool a spider by touching its web so I didn’t even try.
Funnel spider lair. It’s hiding in that hole, Frick Park, 28 July 2024 (photo by Kate St. John)
On the way back we saw red nymph spotted lanternflies. Of course this invasive insect is expendable so … Would the spider come out if we dropped one on his web? Indeed he did and he was fast! He zipped out, stung(?) the nymph, hid for a moment and then raced out and carried the nymph back to his lair.
Yesterday Mike Fialkovich sent news that it’s a big year for boxelder bugs (Boisea trivittata) where he works in New Stanton, PA.
Huge numbers of box elder bug nymphs, New Stanton, 23 July 2024 (photo by Mike Fialkovich)
There was a big gathering of Boxelder Bugs at my workplace today. Most were nymphs but a few adults were present. I noticed the adults were numerous recently on the side of the building but today the numbers of nymphs were impressive.
— email from Mike Fialkovich, 23 July 2024
I was a little surprised to see the swarms on non-native winged burning bush (Euonymus alatus).
Boxelder bug nymphs on winged burning bush, New Stanton, 23 July 2024 (photo by Mike Fialkovich)
As their name suggests, the boxelder bugs’ host plant is the box elder tree (Acer negundo), which is both native and abundant.
Large box elder tree along the trail at Duck Hollow, Pittsburgh, July 2021 (photo by Kate St. John)Box elder leaves, Sept 2020 (photo by Kate St. John)
Soon these nymphs will become adults that look like this … and the bug pictured at top.
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.
