Category Archives: Insects, Fish, Frogs

Thinking About Dung Beetles?

Southern red-billed hornbill (photo from Wikimedia Commons)

13 November 2022

The southern red-billed hornbill (Tockus rufirostris) eats many things but dung beetles and their larvae are at the top of the menu.

Dung beetle with a ball of dung, Manyoni Private Game Reserve, South Africa (photo from Wikimedia Commons)

Elephant dung is an especially good place to find them.

Southern red-billed hornbill looking for … (photo from Wikimedia Commons)

A 2016 study discovered that dung beetles evolved in association with dinosaurs, the ancestors of birds. Beetles were already eating living plants so when flowering plants (angiosperms) sprung up and dinosaurs began eating them, dung beetles evolved to scavenge plant matter found in dung.

However most of the dinosaurs went extinct and their bird ancestors don’t produce dung, so the dung beetles changed their focus to megafauna mammal poop. Elephant dung!

Apparently dung beetles will even fight over it.

So now it’s come full circle. A living dinosaur eats the dung beetles.

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

Miniature Flying Dragons

Artistic reconstruction of ancient flying lizard, Weigeltisaurus jaekeli (image from Wikimedia Commons)

28 October 2022

Back in the Late Permian, 258 to 252 million years ago, there was a family of gliding lizards called Weigeltisauridae whose fossils have been found in Germany, Britain, Russia and Madagascar. Europeans drew them as dragons.

Winged dragon on the ground, illustration in: Athanasius Kircher’s Mundus Subterraneus via Wikimedia Commons

Today there are still gliding lizards on Earth but they are smaller and live in Asian jungles. Dracos can glide 100+ feet from tree to tree by extending their long skin-covered ribs.

Draco taeniopterus flying and Draco volans skeleton (image from Wikimedia Commons)

Watch one fly to escape a dominant male in this BBC Planet Earth II clip.

Learn about Draco dussumieri of Southern India in this video from Roundglass.

Where do Dracos live? Click on the map caption to see a larger view.

(photos, maps, a video and illustrations from Wikimedia Commons; click on the captions to see the originals. videos also embedded from YouTube)

20 Quadrillion Ants & Why It Matters

A line of ants (photo from Wikimedia Commons)

Last week the Washington Post reported that the number of ants on earth is unimaginably large. Scientists from the University of Hong Kong estimated there are 20 quadrillion total or 2.5 million ants for each human being.

They reached this number by combining studies from thousands of researchers around world whose reports span a century. Dedicated ant researchers count ants by literally trapping them or by sweeping them up in leaf litter and counting what they’ve found. Their counts were combined and extrapolated to reach the 20 quadrillion estimate.

Why count ants? To get a benchmark on their population. Our planet is in the midst of an insect apocalypse in which the number of insects has declined 75% over the past 50 years. Butterflies and beetles are the hardest hit. Has the trend affected ants? Soon we’ll know.

Dead painted jezebel butterfly (photo from Wikimedia Commons)

Some of you are probably thinking: Wouldn’t we be better off without bugs? Actually, no. The insect apocalypse matters because bugs provide so many hidden benefits. They consume decayed matter, plant seeds, aerate the soil, pollinate plants and ultimately feed the larger organisms on earth. Their disappearance is especially dire for anything that directly eats insects and anything that eats the insect-eaters. Especially birds.

The decline of insects is one reason why birds have declined 29% in North America in the past 50 years. Hardest hit have been the insect eaters — swallows, swifts and nighthawks. In fact most songbirds feed insects (protein) to their young even if they eat fruits and seeds at other times of year.

Here are just a few of the birds that eat insects at least part of the time. Some of them may surprise you.

  • American redstart with insect (photo from Wikimedia Commons)

Learn more about ants at “The Washington Post: Scientists have calculated how many ants are on Earth. The number is so big it’s ‘unimaginable.’

Read about the insect apocalypse in The Guardian: The insect apocalypse “Our world will grind to a halt without them”.

p.s. Did you know that northern flickers eat ants?

(photos from Wikimedia Commons including insect-eating American redstart, mountain bluebird, barn swallows, olive-sided flycatcher, American kestrel at these links)

The Most Teeth in North America?

Sperm whale skeleton showing teeth (photo from Wikimedia Commons)

19 September 2022

Adult humans typically have 32 teeth after our wisdom teeth come in at age 12-14, but our count is low compared to other animals.

7-year-old smile with missing tooth (photo from Wikimedia Commons)

Which animal in North America has the most teeth?

The Virginia opossum (Didelphis virginiana) is a contender with 50 teeth in his small mouth. He shows them when he feels threatened.

Opossum showing teeth (photo from Wikimedia Commons)

Some say that sharks have the most teeth but as far as I can tell their tooth count, often lower than 100, is not as remarkable as their tooth replacement. For instance, young lemon sharks replace all their teeth every 7-8 days so that in their lifetimes “the lemon shark Negaprion brevirostris, may produce 20,000 teeth in its first 25 years, and may live as long as 50 years.

The winner of the most-teeth contest are land and sea snails which usually have between 10-15,000 teeth, though some may have up to 25,000. This includes snails in the ocean off the North American coasts.

Studies of the European garden snail (Cornu aspersum), an alien in North America, indicate it has 14,000 teeth. Take a look at his toothy mouth under a microscope and find out why snails have so many teeth at NMH.org: Microscopic look at snail jaws.

European garden snail (photo from Wikimedia Commons)

Amazingly, the most abundantly land snail found in Pennsylvania, Zonitoides arboreus, has no teeth at all!

Quick gloss snail, Zonitoides arboreus, Edgewater, Maryland (photo from Wikimedia Commons)

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

Not a Leaf

Not a leaf. An orange oakleaf butterfly, ventral view (photo from Wikimedia Commons)

16 September 2022

This Asian butterfly is a camouflage artist. When its wings are open it’s orange and brown and iridescent blue, below.

Orange oakleaf butterfly, dorsal view (photo from Wikimedia Commons)

But when its wings are closed it looks like a leaf, shown at top.

Touch the “leaf” and it comes alive as an orange oakleaf butterfly (Kallima inachus).

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

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)