Category Archives: Insects, Fish, Frogs

Caterpillar Attracts Attention, Moth Does Not

American dagger moth caterpillar, 13 Sep 2021 (photo by Kate St. John)

18 September 2021

This gorgeous yellow caterpillar is an American dagger moth (Acronicta americana), a 2-inch long member of the owlet family Noctuidae. As a caterpillar he attracts attention.

As a moth he does not.

Adult American dagger moth (photo from Wikimedia Commons)

The difference is a matter of self defense. The adult American dagger moth is probably good to eat so he does his best to hide.

The caterpillar is conspicuous because he has a toxin in his black bristles that cause a stinging sensation when the bristles break off and embed in skin. Like many poisonous animals he’s using aposematic coloration and behavior to simultaneously attract attention and warn off predators, “Look. Don’t eat me.” Other examples include poison frogs, monarch butterflies and skunks.

However, this caterpillar is not invincible like the hickory tussock moth. If you know what you’re doing it’s possible to flatten the black bristles and touch the dagger moth caterpillar as Rebekah D. Wallace does, below, to show the spiracles under the caterpillar’s “fur.”

An expert carefully flattens the bristles to show the lateral spiracles (photo by Rebekah D. Wallace, University of Georgia)

No thanks. I’ll look but not touch.

(photos by Kate St. John, Wikimedia Commons, and Rebekah D. Wallace, University of Georgia via bugwood.org; click on the captions to see the originals)

Check The Antennae

End band net-wing beetle, Frick Park, 6 Sep 2021 (photo by Kate St. John)

14 September 2021

This bug attracted my attention as it fluttered by so slowly that I thought it was a moth.

When it landed I could see its body shape and antennae were wrong for a moth. Moths usually have feathery antennae like this …

Antennae of an Agreeable Tiger Moth (photo by Chuck Tague)
Antennae of an Agreeable Tiger Moth (photo by Chuck Tague)

… whereas this bug has segmented antennae, as seen in this photo from Wikimedia Commons.

iNaturalist told me it was an “end band net-wing beetle (Calopteron terminale).” The black tip on the elytra (wing coverings) is the “end band.” The large and membranous “net-wings” are covered when the beetle is at rest. Click here to see him with open wings.

In flight I thought he was a moth because “This beetle is a strong, but slow, lumbering flier,” according to North American Insects and Spiders.

Check the antennae to narrow the possibilities. On beetles they can be whimsical.

Longhorn Beetle “Whitespotted Sawyer,” Sequoia National Park (photo from Wikimedia Commons)
Click beetle with antler-like antennae, Tsu, Japan (photo from Wikimedia Commons)

(photos from Kate St. John, Chuck Tague and Wikimedia Commons)

Leaf Miner on White Snakeroot

Leaf mine on white snakeroot, 19 August 2021, Frick Park (photo by Kate St. John)

5 September 2021

Have you seen an unusual white squiggle on a green leaf? The pattern was made by a leaf miner, a tiny insect larva that eats a path between the top and bottom surfaces of the leaf.  The path ends when the larva is ready to pupate. When the insect departs it leaves a hole.

There are many tiny moths, beetles, sawflies and flies that make leaf mines. Some create blotches. Others, like this one, make serpentine paths. You can identify the insect(s) that made the paths — or at least narrow the number of species — by noting the type of mine and identifying the plant host.

This serpentine leaf mine was on white snakeroot (Ageratina altissima) in Frick Park on 19 August. Based on the Illinois Wildflowers list of insects that feed on Ageratina altissima, here are two possible suspects that create serpentine leaf mines and live in Pennsylvania.

  • The larvae of a tiny fly, Liriomyza eupatoriella. (NOTE: While researching this insect I discovered Charley Eiseman, an expert on leafminers and author of the only photo of the bug at bugguide.net. More on Charley Eiseman below.)

If you want to know more about leaf miners, go to the expert. Check out Charley Eiseman‘s book, Leafminers of North America or visit his BugTracks blog where he writes about all kinds of insects. He’s even discovered new species.

(photos by Kate St. John, screenshot of bugguide.net and photo from Wikimedia Commons)

Disappearing In The Sand

Coquina clams, open shells, Corpus Christi (photo by Pinke via Creative Commons license)

31 August 2021

Coquina clams (Donax variabilis) are tiny saltwater molluscs found on sandy beaches from Virginia to Texas. Their variable colors are beautiful and at only 3/4 inch long they are just the right size for collecting. I usually find an empty half shell rather than two joined like butterfly wings (above).

Colors of coquina clams (photo by Florida Fish & Wildlife via Flickr Creative Commons license)

Since I only pay attention to empty shells I never thought about where they live and how they get there until I saw this video. Watch two coquina clams disappear in the sand.

(photos from Pinke via Flickr and Florida Fish & Wildlife on Flickr)

Cicada Outside My Window

Scissor-grinder cicada outside my window, 27 Aug 2021, 8pm (photo by Kate St. John)

28 August 2021

Last night at sunset I heard a bug outside my window and found a scissor-grinder cicada (Neotibicen winnemanna) perched on the bricks outside the glass. He sang his courtship song to attract a mate, a repetitive WEEE ah, WEEE ah, WEEE ah, WEEE ah that tapers at end. It’s a sound so unique that he can be identified by song. Click here to hear.

When the cicada left he flew directly at my window and bounced off the glass, over and over again. I imagine his 5 eyes were fooled by a reflection of the sky.

Cicada closeup (photo by Dana Nesiti)
Cicada closeup (photo by Dana Nesiti)

Don’t confuse our annual cicadas with the 17-year periodical cicadas that emerged in D.C. last May and disappeared in July. Scissor-grinders emerge every year in July and peak in September and they look different from each other.

Annual cicada in Pittsburgh, probably scissor-grinder.
Annual cicada, 5 Aug 2019 (photo by Kate St. John)
17-year cicadas are not in Pittsburgh this year. See the red eyes!
Magicicada sp. is not in Pittsburgh in 2021 (photo from Wikimedia Commons)

(photos by Kate St. John, Dana Nesiti and from Wikimedia Commons)

Now You See Me, Now You Don’t

Biston betularia caterpillars on birch and willow (photo from Wikimedia Commons)

27 August 2021

Moths are eaten by birds, small rodents, bats, and lizards and are especially vulnerable during the day. To avoid predation many hide in plain sight. Here are four moths that use camouflage to survive.

The peppered moth (Biston betularia) is a camouflage master. The adults look like bark, the caterpillars (above) look like twigs.

Research indicates that the caterpillars can sense the twig’s color with their skin and match their body color to the background to protect themselves from predators.

Wikipedia: peppered moth

You can see an adult peppered moth on a plain surface …

… but on birch bark you (mostly) don’t. This particular moth could have roosted on a darker spot but then we’d think the photo was just bark.

The buff tip moth (Phalera bucephala), native to Eurasia, is visible on a mothing cloth …

Buff tip moth, Phalera bucephala (photo from Wikimedia Commons)

… but matches a birch twig in the wild.

Buff tip moth on twigs (photo from Wikimedia Commons)

The pandora sphinx moth (Eumorpha pandorus) is large and easy to see on plain surfaces.

Pandora sphinx moth (photo from Wikimedia Commons)

Here’s why he is green.

Pandora sphinx moth camouflage (photo from Wikimedia Commons)

And finally, this is the moth that inspired this article.

Now you see me. Now you don’t.

(photos from Wikimedia Commons; click on the captions to see the originals)

Adapted to an Invasive Tree

Ailanthus webworm moth, Cape Cod 2018 (photo by Bob Kroeger) The light makes black look blue.

18 August 2021

Here’s a beautiful moth we wouldn’t see if it weren’t for an invasive tree.

The ailanthus webworm moth (Atteva aurea) is a tropical ermine moth that relied on the paradise tree (Simarouba glauca) and Simarouba amara as its larval hosts. In the U.S. this limited the moth’s range to South Florida.

However in 1784 we began importing an Asian member of the Simaroubaceae family, the tree of heaven (Ailanthus altissima), because we thought it was pretty. We sold it as a landscaping tree for over 100 years. It became invasive and spread across the US and into Canada (map by state/province below).

Ailanthus range in North America (EDDMaps)

Ailanthus is also a host for Atteva aurea so the moth spread with the tree, earning it the common name Ailanthus webworm moth. This daytime moth now ranges from Florida to Texas and across eastern North America to Minnesota and Ontario.

It is really very beautiful …

… and tiny.

I’m not surprised I haven’t seen one yet.

But maybe I’ll find its webs on an Ailanthus tree.

Keep a look out for this gorgeous little moth that adapted to an invasive tree.

p.s. The blue color on the moth at top is just a trick of the light but it makes him even more beautiful.

(top photo by Bob Kroeger, remaining photos from Wikimedia Commons; click on the captions to see the originals)

Insects Like It Hot

Zabulon skipper (Lon zabulon) on my thumb, 9 August 2021 (photo by Kate St. John)

16 August 2021

Last week was hot in Pittsburgh in both temperature and humidity. On mornings when it was only 71 degrees the dewpoint was also 71 so it felt oppressive. Under the circumstances birds are scarce but insects are not.

Above, a Zabulon skipper (Lon zabulon) butterfly that was sipping on ironweed flew over to land on my thumb. It was hard to take its picture without scaring it away.

Ironweed florets are shaped like tubes, perfect for the skipper’s probocis.

Skippers visiting ironweed, 9 August 2021 (photo by Kate St. John)

Hickory tussock moth caterpillars are easy to find this month.

And two kinds of insects are attacking the Japanese knotweed — aphids and Japanese beetles.

Aphids on Japanese knotweed, 8 August 2021 (photo by Kate St. John)

It is very fitting that an invasive Japanese beetle eats an invasive Japanese plant.

Japanese knotweed: leaves with bug holes, aphid son the stem (photo by Kate St. John)

Insects are busy. They like it hot.

(photos by Kate St. John)

Handsome Bug

Red-headed bush cricket, the handsome trig (photo from Wikimedia Commons)

9 August 2021

The birds stopped singing weeks ago but the air is filled with the sound of bugs. One of them is the red-headed bush cricket (Phyllopalpus pulchellus) otherwise known as the Handsome Trig.

If you find a handsome trig you can see the beauty that gave him his name. Unfortunately he’s so tiny that we rarely see him.

However, you can hear him. He sings very loudly at 7000 Hertz, often from a Japanese honeysuckle thicket.

I say “You can hear him” because I cannot. I’ve lost my hearing above 6,000 Hertz so I view his voice as a spectrogram on the Spectroid app. The very bright white-orange stripe at 7406 Hertz is the LOUD sound of the handsome trig in the video above. The fainter line at 4,000 hertz is quieter and the only part of his sound that I can hear.

Spectrogram of handsome trig song in video above

Listen for this handsome bug.

Tell me if he’s loud. 🙂

(photo from Wikimedia Commons, videos embedded from YouTube; click on the captions or the YouTube logo to see the originals)

Big Snake Plays Possum

Eastern hognose snake playing dead (photo from Wikimedia Commons)

29 July 2021

Here’s a snake you don’t need to be afraid of because …

  1. The only way to get bitten by an eastern hognose snake is to smell like its prey.”
  2. If you frighten him he will try bizarre defensive moves (which can frighten you) but if they don’t work he plays dead. Very dead.

Learn about his bizarre defensive moves in this vintage article: S is for Snake.

p.s. The trick is knowing that you’re dealing with an eastern hognose snake. I don’t know how.

Eastern hognose snake (illustration from North American Herpetology via Wikimedia Commons)

(photos from Wikimedia Commons; click on the saptions to see the originals)