Stiltgrass carpeting the ground in Schenley Park, 16 August 2024 (photo by Kate St. John)
25 August 2024
At this time of year the woods in southwestern Pennsylvania often look as if gardeners have removed all the underbrush and left a thick carpet of grass on the forest floor. The “gardeners” are overabundant white-tailed deer who selectively eat their favorite foods and leave behind invasive Japanese stiltgrass (Microstegium vimineum).
Japanese stiltgrass came to the U.S. in packing crates in the early 1900s as padding to protect porcelain shipped from China. Of course we threw it out when we unpacked the crates. It took root and was discovered in Tennesse in 1919. More than 100 years later it blankets much of the eastern U.S.
Range map of invasive Japanese stiltgrass in North America (EDDMapS. 2024. Early Detection & Distribution Mapping System. The University of Georgia – Center for Invasive Species and Ecosystem Health. Available online at http://www.eddmaps.org/; last accessed August 25, 2024.)
Japanese stiltgrass is easy to identify because it has a shiny midrib (topside) and the midrib is not in the middle of the leaf (underside).
Shiny midrib on topside of Japanese stiltgrass leaf (photo by Kate St. John)
Japanese stiltgrass mid rib is not in the middle. Back of the leaf: (photo by Kate St.John)
Amazing as it seems, Japanese stiltgrass is an annual that dies every winter and grows back from seed the next spring. Its thick green carpet in summer shades out native species.
Japanese stiltgrass carpet, Butler-Freeport Trail, July 2017 (photo by Kate St. John)
After it goes to seed in early fall it dies and becomes a brown drape over the landscape in winter. This gives it the alternate common name of “Nepalese browntop.”
Japanese stiltgrass comes back thickly every year because it drops so much seed in the soil. It’s possible to get rid of it … eventually .. through hand pulling or goats. Pittsburgh Parks Conservancy is using both techniques in Hays Woods this year.
Giant ragweed in bloom, Hays Woods, 20 Aug 2024 (photo by Kate St. John)
24 August 2024
This week I encountered giant ragweed (Ambrosia trifida) along the trail at Hays Woods. Though the plant I photographed was still shorter than me it typically reaches six feet tall. The flower spikes are loaded with male pollen flowers, facing downward to dangle in the wind and spread the pollen that makes many people sneeze.
Giant ragweed in bloom, Hays Woods, 20 Aug 2024 (photo by Kate St. John)
If you suffer from ragweed allergies your nose knows when it started blooming but you might not know what common ragweed (Ambrosia artemisiifolia) looks like. What is making you miserable? Check out this vintage article.
Almost four years ago, artist and photographer Robert E. Fuller posted this video of a baby wild stoat playing on a trampoline in his garden in the U.K.
Fuller has observed wild stoats for many years at his home in Yorkshire. The baby stoat that played on the trampoline in autumn 2020 appears to have started a trend. His video posted in July 2021 shows mother and kits at the same playground.
Yes, they are very cute, but … wild weasels are not good pets and it is illegal to keep them without a wildlife permit. If you want a pet weasel, get a ferret.
It’s relatively hard to find a singing cricket because the male is on the ground, probably hidden by vegetation, and facing the entrance to his burrow. He rubs his modified leathery front wings, called tegmina, to make his chirping sound.
The burrow entrance provides an echo chamber that amplifies his sound and, if his chirping attracts a predator, he can quickly zoom underground for safety.
Did you know that the cricket’s chirp can tell you the temperature? Count the number of chirps of a lone cricket for 15 seconds, then add 37. That should tell you the temperature in Fahrenheit … probably. If it doesn’t, I like to imagine that the burrow entrance is colder or hotter than the ambient air. 😉
Read more about the cricket’s chirp here at the Songs of Insects.
p.s. Did you ever have a cricket in your house? In my experience they are really hard to find unless they’re in the corner of a gleaming white bathroom and you’ve moved everything out of the way to find the cricket in the corner.
Biennial gaura, Hays Woods, 20 August 2024 (photo by Kate St. John)
21 August 2024
When I took this photo at Hays Woods yesterday, I knew the plant’s name — biennial gaura — but just for fun I asked PictureThis to identify it. It said “Biennial Gaura, a species of Evening Primrose.” Evening Primrose was a surprise. I didn’t think they were related.
Common evening primrose (Oenothera biennis) has four evenly spaced petals with stamens and pistil in the middle. Though the flower appears to be open here, it actually opens more widely in the evening.
Evening primrose, September 2020 (photo by Kate St. John)
Biennial gaura (Oenothera gaura) also has four petals but they are all on one side of the stem with stamens and pistil drooping below. The shape of the flower looks “irregular” to me and “evening” doesn’t seem to apply either. The flower looks like it stays open all day.
Biennial gaura (photo by Kate St. John)
However, studies of the former genus Gaura caused all of it to be absorbed into Oenothera (Evening Primrose ) in 2007. The reason I was surprised 17 years later is that my hardback copy of Newcomb’s Wildflower Guide was published in 1997. I should rely more on apps these days.
Here are additional photos of both flowers for further comparison.
Biennial gaura, Hays Woods, 7 Sep 2022 (photo by Kate St. John)Common evening primrose near Herrs Island, 18 Aug 2024 (photo by Kate St. John)
Both plants are “weedy” species so they’re pretty easy to find in the field. Look for common evening primrose in sunny or mostly sunny places, often along trails. Biennial gaura wants full sun and dry, rocky soil. At Hays Woods it grows at the powerline cut.
Note that biennial gaura flowers are much smaller than evening primrose. Tiny but beautiful.
Female black swallowtail butterfly in Betty Rowland’s garden, 18 August 2024 (photo by Betty Rowland)
20 August 2024
You may remember in early August when I wrote that two friends had black swallowtail caterpillars (Papilio polyxenes) in their gardens. By now those caterpillars are, or will soon become, butterflies.
After Betty Rowland discovered her caterpillars on 1 August her neighbor, Aaron Johnson, loaned her a butterfly tent.
Two black swallowtail caterpillars on fennel, 1 August 2024 (photo by Betty Rowland)Shelter to protect the caterpillars from predation, 2 August 2024 (photo by Betty Rowland)
Soon thereafter, on 4 August, one caterpillar posed in the pre-chrysalis position and the other had already become one.
Black swallowtails: Caterpillar in pre-chrysalis position (left) and chrysalis (right), 5 August 2024 (photos by Betty Rowland)
Last Sunday I heard from Betty that after two weeks both black swallowtail butterflies had eclosed (emerged from chrysalis).
Two black swallowtail butterflies, discarded chrysalis is circled, 18 August 2024 (photo by Betty Rowland)
Both are female (photo at top) which is easy to see from their coloration. Female black swallowtails have orange and blue highlights; males have yellow highlights with only a hint of orange and blue (male pictured below).
Dress for the weather and wear comfortable walking shoes. Bring binoculars and field guides if you have them. If it’s hot be sure to bring water, sunscreen and a hat.
Visit my Events page before you come in case of changes or cancellations. The outing will be canceled if there’s lightning or heavy downpours.
The fogging is done at dusk and night by a pickup truck with a dispersal (fogging) unit using insecticide Zenivex E20 (active ingredient etofenprox). I don’t have photos of ACHD’s trucks — this mosquito control truck is in Cuba, not in Allegheny County — but the photo gives you an idea of what fogging looks like. See photos of local fogging in the PublicSource article, linked above.
Etofenprox is a pyrethroid derivative which disturbs insect nervous systems following direct contact or ingestion. It is active against a broad spectrum of pests including Lepidoptera (butterflies and moths), Hymenoptera (bees, wasps, ants), Diptera (flies and mosquitoes), Hemiptera (cicadas, aphids, leafhoppers, bed bugs, shield bugs), Coleoptera (beetles), and Thysanoptera (thrips).
The fogging creates a miniature insect apocalypse for small night-flying insects touched by the insecticide. This ripples up the food chain to the plants, birds and animals that rely on them. One of them is my spark bird, the common nighthawk. PublicSource points out:
A bird conservation advocate agreed that nighttime pollinators could be affected, which could have ripple effects in bird populations, such as the common nighthawks that feed after dusk.
“Even when these products are used with the best intentions … in a highly targeted manner, they certainly do have the potential to affect non-target invertebrates,” said Hardy Kern, director of government relations of the birds and pesticides campaign at the American Bird Conservancy. “And these non-target invertebrates are really important food sources for birds.”
— PublicSource: Allegheny County ramps up mosquito control. Could it harm local ecosystems?
However, “The county wouldn’t need to spray as much if more people knew how to keep mosquitoes from breeding near their homes.”
And that’s where you come in. Mosquitoes breed in stagnant water. If you have standing water in your yard mosquitoes will breed there — even in a bottle cap. Dump out the standing water to kill the larvae. Dump out abandoned tires!
If you are being bitten by mosquitoes it’s most likely that those mosquitoes are being produced on your property. Mosquitoes do not like to travel very far. They are very weak fliers, and if they can find all the things that they need to survive on your property that’s where they will begin and end their life cycle.
— quote from PA DEP Video: Help Prevent Mosquitoes from Breeding
Black-throated green warbler, Frick Park, 14 Aug 2024 (photo by Charity Kheshgi)
17 August 2024
This was a week of still-nesting swallows, pretty flowers, migrating warblers, and many, many deer in the city parks.
Moraine State Park, 11 August. Charity Kheshgi and I were surprised to see cliff swallows still nesting on 11 August at the Rt 528 Boat Launch area. Parents were feeding young at four to five nests.
Cliff swallows with young in nest, Moraine State Park, 11 Aug 2024 (photo by Charity Kheshgi)
Late summer flowers: Best photos this week are butter-and-eggs (non-native), spreading dogbane and blue vervain.
Butter and eggs, in the snapdragon family, Southside Riverfront Park, 12 August (photo by Kate St. John)Spreading dogbane, Moraine State Park, 11 August 2024 (photo by Kate St. John)Blue vervain, Southside Riverfront Park, 12 August (photo by Kate St. John)
Warblers at Frick Park: On 14 August Charity Kheshgi and I saw a good flock of warblers on Trough Trail. Blackburnians were still considered rare on the 14th (too early for them) but we found five! Here’s one eyeing a bug on Japanese angelica, a devil’s walking stick look-alike.
Blackburnian warbler, Frick Park, 14 Aug 2024 (photo by Charity Kheshgi)
We recognized distinctive plumage on each of the 5 Blackburnians. As if to prove there were so many, three posed in one shot.
3 Blackburnian warblers in one shot, Frick Park, 14 Aug 2024 (photo by Charity Kheshgi)
We also saw one immature chestnut-sided warbler hanging out in the flock.
Immature chestnut-sided warbler, Frick Park, 14 Aug 2024 (photo by Charity Kheshgi)
Deer: Schenley and Frick Parks, 14 and 16 August
It was a big week for deer in the city parks. I saw 10 in Frick on Wednesday, and 9 in Schenley on Friday. Of the 9, more than half were young or spotted fawns that were born this year. If my tally is representative, the Schenley deer population has doubled itself in just one year.
3 deer in Frick Park, 14 Aug 12024 (photo by Kate St. John)
I believe that the doe in this photo is shedding her summer fur (rusty color) to switch to her winter coat (gray-brown).
Spotted fawn with doe in Schenley, 16 Aug 12024 (photo by Kate St. John)2 of the 9 deer seen in Schenley on 16 August 2024 (photo by Kate St. John)
Why are deer so easy to see in Schenley Park? Because there is no underbrush to hide them. There are so many deer that they ate all the underbrush. So there’s nowhere to hide.
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.
