Category Archives: Insects, Fish, Frogs

How Do Spiders Travel 1,000 Miles?

Trashline orbweaver, Cyclosa turbinata, a spider that flies (photo by J Maughn via Flickr Creative Commons license)

12 September 2022

Mainland spiders are found on remote islands 400 miles from the nearest land and have been noted by ships 1,000 miles at sea. How did they get there?

When baby spiders (spiderlings) disperse and when lightweight species really want to go places they wait for a light wind and electrically charged air. When conditions are right they stand on a high exposed spot on extended legs, tip up their back ends, and eject several gossamer threads from their spinnerets.

Pardosa spider ejecting gossamer, attempting to balloon (photo from Wikimedia Commons)

The silk automatically forms a lightweight triangular shaped parachute and, because its electrical charge matches the ground and is opposite to the air, it’s repelled from below and pulled into the sky. The gossamer parachute rises up and away and drags the spider with it. And he’s off! Flying backwards thanks to static electricity.

This action, called ballooning, can carry an individual spider at least 1,000 miles on a light wind and two to three miles above the earth (10,500-16,000 feet). The spider can stay airborne over open ocean and thus colonize an island.

Not all spiders go ballooning but the species that do, like the trashline orbweaver (Cyclosa turbinata) pictured at top, have quite a wide distribution.

How can you tell that tiny spiders have been flying? When you see lots of spider silk clinging to branches in a light breeze you’ve found the aftermath of a mass ballooning event.

Read more about spider ballooning at Ask Nature: Spiders Fly Riding Electric Current and at Spiders Colonized A Remote Pacific Island By Flying There.

See the original University of Bristol study, July 2018, at Science Direct: “Electric Fields Elicit Ballooning in Spiders”.

(photo credits are in the captions, click on the captions to see the originals)

Look Who Eats Spotted Lanternflies!

Spotted lanternfly in Pittsburgh, 23 July 2022 (photo by CBailey via Wikimedia Commons)

11 September 2022

Ever since spotted lanternflies (Lycorma delicatula) made their disgusting appearance this July in Pittsburgh we’ve been crushing and smashing them, but it’s clear that we humans can barely make a dent in the population. Most of the bugs fly way above our heads and land high in the trees. We can’t reach them but someone else can.

Foot about to crush a spotted lanternfly (photo from Wikimedia Commons)

Spotted lanternflies are completely new to North America’s native species, but the bugs look like food so Nature is stepping in to eat them. Predation results are far more successful than our smashing.

Who eats spotted lanternflies? You can see their photos in the Creative Commons licensed iNaturalist group: Spotted Lanternfly Predation in the U.S. Most entries are from New York City, New Jersey and Philadelphia. (Hey, Pittsburgh, post yours too!) Here are just a few examples.

Below, a great crested flycatcher eats a spotted lanternfly in Central Park, NYC. This photo was also tweeted by its author Hector Cordero (@CorderoNature).

Great crested flycatcher eating spotted lanternfly, Central Park NYC (Creative Commons photo by corderonature via iNaturalist)

A red-bellied woodpecker plucks a spotted lanternfly off a dead snag in Philadelphia.

Red-bellied woodpecker eating a spotted lanternfly (Creative Commons photo by tb_wildlife_photography via iNaturalist)

Many spiders eat the lanternfly. Here’s one wrapped in webbing in New Jersey.

The author of this photo in New Castle, Delaware says “Spotted lanternfly being consumed (violently) by a yellowjacket.”

Yellowjacket eating spotted lanternfly (Creative Commons photo by jfrancismd via iNaturalist)

Hooray for praying mantis! “A mantis devouring a spotted lanternfly in Staten Island NY.”

Praying mantis eating spotted lanternfly (Creative Commons photo by britty705 via iNaturalist)

Oh my! A fungus — Icing Sugar Fungus (Beauveria bassiana) — is consuming this lanternfly near Allentown, PA.

Icing sugar fungus on spotted lanternfly, near Allentown PA (Creative Commons photo by cecildomyiidae via iNaturalist)

Remember: Don’t spray pesticides to combat the spotted lanternfly. You don’t want to poison the helpers!

Read more about U.S. predators of the spotted lanternfly at Audubon.org: Birds Are One Line of Defense Against Dreaded Spotted Lanternfly.

UPDATE 18 Sep 2022, this post has attracted many new readers & commenters and has prompted this NOTE TO COMMENTERS –> Comments on this blog are moderated. If you post a comment that is profane or could inflame others, I will edit it or delete it.

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

Dung Beetles Navigate By Looking at the Sky

Sacred scarab beetle rolling a dung ball with its hind legs, Ukraine, 2015 (photo from Wikimedia Commons)

4 September 2022

Dung beetles coexist with large animals because their entire life cycle depends on the droppings of cattle, elephants and other mammals. When Scarabaeus beetles find a dung pile each one makes a ball and uses its hind legs to roll the ball away from competitors, then buries it in a private location for later consumption. Here a sacred scarab beetle (Scarabaeus sacer) rolls and digs.

To move a dung ball the Scarabaeus beetle travels backwards in a straight line against all obstacles. When the ball rolls off course, the beetle climbs to the top, reorients itself and resumes pushing in the correct direction. This so impressed the Ancient Egyptians that they venerated the sacred dung beetle (Scarabaeus sacer) and carved amulets in its image(*).

How do these beetles navigate?

A 2015 study of South African Scarabaeus lamarcki found that the beetles use the sun’s direction and the variation in the sky’s green and ultraviolet colors like a compass. For example, this S. lamarcki beetle travels in the exact opposite direction when researchers use a mirror to show the bug reflected sunlight.

And a 2019 study found that they also pay attention to the wind when the sun is too high to help. See “(Not only) the wind shows the way.”

Traveling upside down and backwards requires lots of navigational tools.

(*)p.s. Did you know that the sacred dung beetle, Scarabaeus sacer, is the origin of scarab jewelry?

The scarab (kheper) beetle was one of the most popular amulets in ancient Egypt because the insect was a symbol of the sun god Re. … The scarab forms food balls out of fresh dung using its back legs to push the oversized spheres along the ground toward its burrow. The Egyptians equated this process with the sun’s daily cycle across the sky, believing that a giant scarab moved the sun from the eastern horizon to the west each day, making the amulet a potent symbol of rebirth.

MeTropolitan Museum of Art: Egyptian Art, Scarabs
Ancient Egyptian scarab amulets from Middle Kingdom, Metropolitan Museum of Art (photo from Wikimedia Commons)

Millennia later, a scarab jewelry pin from the late 1960’s.

Scarab jewelry pin, late 1960s U.S. (photo by Kate St. John)

(photos from Wikimedia Commons and Kate St. John; click on the captions to see the originals)

One Flap, 15 Moths

Polyphemus moth mug shot (photo from Wikimedia Commons)

2 September 2022

When we say that a bird has “moth-like flight” do we mean that its wings move like this? Check out Dr. Adrian Smith’s fifteen moths in slow motion flight.

p.s. Polyphemus moth species is shown above. Can you find it in the video?

(photo from Wikimedia Commons, tweet embedded from @DrAdrianSmith)

Scarabs

Glorious scarab beetle (photo from Wikimedia Commons)

1 September 2022

There are more than 30,000 beetles in the Scarab family (Scarabaeidae), most of them active only at night.

Screenshot of Scarab beetles at bugguide.net

The Glorious Scarab Beetle (Chrysina gloriosa) pictured at top was hiding underground when gardening unearthed it in its native US range of Arizona, New Mexico, Texas.

Hidden gems include Beyer’s scarab which I saw in southeastern Arizona in 2015, described in this vintage article: Like a Jewel.

Beyer’s Scarab Beetle (Chrysina beyeri) at Carr Canyon, Arizona, 30 July 2015 (photo by Kate St. John)

In the eastern US we have beautiful scarab beetles in our own backyards.

Which scarab beetle is this? (photo from Wikimedia Commons)

But we don’t think they’re beautiful because they eat our roses.

Japanese beetle (photo from Wikimedia Commons)

Japanese beetles (Popillia japonica) are scarabs.

(photos from Wikimedia Commons, bugguide.net and Kate St. John, click on the captions to see the originals)

Insects, Deer, a few Birds Yesterday at Schenley

7-point buck in Schenley Park, 28 Aug 2022 (photo by Connie Gallagher)

29 August 2022

A year ago in Schenley Park we had such a slow birding day that I wrote, “We worked for every bird.” A year later, nine of us were there yesterday and the birding was even slower! (14 species instead of 19.) However we found lots of insects and two white-tailed bucks in velvet. Here’s the story in pictures, thanks to Connie Gallagher.

Connie saw the very Best Bird, a blue-gray gnatcatcher.

Blue-gray gnatcatcher, Schenley Park, 28 August 2022 (photo by Connie Gallagher)

We pondered the identity of these wasps and then remembered, all at once, that they are bald-faced hornets (Dolichovespula maculata), a type of yellowjacket wasp.

Bald-faced hornets at their paper nest in a pignut hickory, Schenley Park, 28 Aug 2022 (photo by Connie Gallagher)

There was still dew on the wild senna as this bumblebee gathered nectar.

Bumblebee on wild senna, Schenley Park, 28 Aug 2022 (photo by Connie Gallagher)

The browseline is so severe in Schenley Park that there’s no cover for the deer who sleep there during the day. Looking down from the Falloon Trail we saw two bucks, a 7-point buck (at top) and a 10-point below.

10-point buck in Schenley Park, 28 Aug 2022 (photo by Connie Gallagher)

Fortunately some of us heard these birds flying overhead. I can tell their identity by shape and the yellow tips of their tails. Cedar waxwings.

Cedar waxwings fly over, Schenley Park, 28 Aug 2022 (photo by Connie Gallagher)

Here’s the group that worked for every bird on Sunday. Thank you all for coming!

Schenley Park outing, 28 August 2022 (photo by Kate St. John)

See our checklist at https://ebird.org/checklist/S117700393 and printed below.

Schenley Park–Panther Hollow, Allegheny, Pennsylvania, US
Aug 28, 2022 8:30 AM – 10:30 AM, 1.5 mile(s), 14 species

Mourning Dove (Zenaida macroura) 5
Chimney Swift (Chaetura pelagica) 4
Red-tailed Hawk (Buteo jamaicensis) 1
Red-bellied Woodpecker (Melanerpes carolinus) 2
Downy Woodpecker (Dryobates pubescens) 1
Northern Flicker (Colaptes auratus) 1
Eastern Wood-Pewee (Contopus virens) 1
Blue Jay (Cyanocitta cristata) 7
Blue-gray Gnatcatcher (Polioptila caerulea) 1 Seen by Connie
American Robin (Turdus migratorius) 1
Cedar Waxwing (Bombycilla cedrorum) 5
American Goldfinch (Spinus tristis) 3
Common Grackle (Quiscalus quiscula) 1
Northern Cardinal (Cardinalis cardinalis) 3 Including a bald female Cardinal

(photos by Connie Gallagher (group photo by Kate St. John))

Moving a Predator into Position

House centipede closeup (photo from Wikimedia Commons)

25 August 2022

Since moving to the 6th floor of a high-rise two years ago we have had no indoor bugs at all. Then, about a week ago, two extremely small bugs with waists and knobbed antennae showed up on the kitchen floor, standing there just outside the bottom of the stove.

They are not interested in water or sweets but only rarely attracted to a very tiny bit of grain or seed. They never fly. They just walk slowly — so slowly that it’s easy to catch one and put it in a ziploc bag (shown below).

Mystery insects (in ziploc bag) compared to a penny for size (photo by Kate St. John)

Finding two bugs was a curiosity but a week later finding 20 bugs every morning felt like a problem. I checked inside my food cupboards — no bugs at all — and gave my bug-ziploc to building maintenance who is checking for bugs in adjacent units. I’m not to spray in case there will be a multi-floor solution in the days ahead.

Meanwhile Nature’s solution to tiny bugs ran right up to me.

House centipede (photo form Wikimedia Commns)

This morning a house centipede (Scutigera coleoptrata), a top predator of insects, ran toward me across the carpet. I screamed! Then I remembered he would eat those little bugs if I could just catch him alive and carry him to the kitchen.

Catching a centipede on the spur of the moment is very tricky. (They run fast!) I fashioned a piece of paper to enclose him and got him to run onto the paper but time after time he ran out the corners of the trap. Finally I enclosed him, carried him to the kitchen, and let him loose below the stove.

Centipede trap and carry (re-enactment photo by Kate St. John)

A top predator has been moved into position under the stove. I can hardly wait for the house centipede to eat those mystery bugs!

Learn more about house centipedes in this vintage article.

p.s. No, I did not add a centipede. I just moved one about 20 feet.

And I am wondering… Are the mystery bugs actually sawtoothed grain beetles (Oryzaephilus surinamensis)? If so they arrived in someone’s groceries.

(photos by Kate St. John and from Wikimedia Commons; click on the captions to see the originals)

Not Caterpillars

Two of thousands of insect larvae in trees over Nine Mile Run, 13 August 2022 (photos by Kate St. John)

20 August 2022

Last weekend in Lower Frick Park Charity Kheshgi and I saw thousands of caterpillars and a lot of frass dropping from the trees above the pedestrian bridge over Nine Mile Run (pictured above).

Many insects are specialists, consuming a single plant family or genus during in their larval phase. If you can name the plant the caterpillar is eating, you can narrow down the identity of the bug.

Using that method I tried to name the leaves the caterpillars were skeletonizing (eating habits are another clue!) but most were too damaged to identify. Eventually I found a few intact elm-like leaves.

The photo match for “larvae that skeletonize elm leaves” included an adult form matches the golden yellow mystery beetle I saw this summer in Frick Park. These are larger elm leaf beetles (Monocesta coryli).

Larger elm leaf beetle (Monocesta coryli) (photo from bugwood by Gerald J Lenhard, LSU)

The “larger” beetle is a pretty big bug, shown for scale on someone’s hand in this photo by Bill Sweeney embedded from bugguide.net, and its color varies. Click here to see an orange one.

Here’s what it will do next.

There is only one generation per year. Eggs are laid in the spring in “hard yellow crusty” masses of 24 to 58 eggs on the undersides of elm leaves. They hatch in about two weeks.

The newly eclosed larvae are about 3 mm long and greenish-yellow. They are gregarious for three to four days and feed on leaf surfaces before dispersing. The mature larvae crawl down the tree and undergo a wandering phase for a few days before entering the ground, where they remain until pupation the following late winter or early spring. Pupation lasts about a month and adults begin emerging in April. Adults are active from April until early August, with most records from June to July. Both adults and larvae exude an orange, presumably defensive, fluid when disturbed.

Univ of Florida Entomology: Larger Elm Leaf Beetle

So why are these not caterpillars? Because the larvae of beetles are called “grubs.”

(photos from bugwood, from bugguide and by Kate St. John, click on the captions to see the originals)

Seen This Week

Long shadows are back again, 12 August 2022 (photo by Kate St. John)

20 August 2022

The days are getting shorter and shadows are getting longer. Pittsburgh had one and a half more hours of daylight on the summer solstice, just two months ago, than we do today.

Late summer flowers are attracting bees.

Allium flower with bee, 16 August 2022 (photo by Kate St. John)

Ornamental grasses are going to seed.

Ornamental grass at Phipps (photo by Kate St. John)

And the clouds have been interesting.

Puffy clouds over Millers Ponds, Crawford County, 15 August 2022 (photo by Kate St. John)

Can you see the face in the cloud below?

Glowing eyes in the face in the cloud, 17 August 2022 (photo by Kate St. John)

Keep looking up.

(photos by Kate St. John)

Air Pollution Confuses Bees and Butterflies

Honeybee on wingstem (photo by Kate St. John)

18 August 2022

We know that air pollution hurts humans. It is also bad for agriculture in an unexpected way. A study published in early 2022 by the University of Reading revealed that air pollution confuses bees and butterflies and reduces their pollination efforts.

Scientists from the University of Reading, the UK Centre for Ecology & Hydrology, and the University of Birmingham found that there were up to 70% fewer pollinators, up to 90% fewer flower visits and an overall pollination reduction of up to 31% in test plants when common ground-level air pollutants, including diesel exhaust pollutants and ozone, were present.

Technology Networks Applied Sciences: Pollination Reduced As Bees and Butterflies Confused by Air Pollution

The pollutants react with and change the scents of flowers, making them harder to find. “It can just make them not smell anything at all,” said lead author James Ryall.

Perhaps the bees are also confused by the load of particulate pollution that clings to their bodies via static electricity. Read more below.

Air pollution is not just bad for us, it’s bad for our food supply.

(photo by Kate St. John)