Is it a Worm? Is it a Wasp? No! It’s the Elm Sawfly!

This past weekend as I sat below an old oak tree while drinking my morning cup of coffee and looking out on a glassy Lake Darling in Alexandria, Minnesota, something fell from the sky and landed at my feet. Small and curled up like a slightly puff green and yellow sour gummy worm. It’s face made it look like a Pokémon, or like one of those smiley face antenna toppers. Two hours later, another fell in the same exact spot. If I didn’t already know what it was, I would think it was a caterpillar of some sort.

It’s adult form is even more deceiving. Last summer my mother in-law killed one on the very same patch of land worries that it was a wasp of some sort. It was then that I first looked into it’s true identity and also happened across the first larvae of the species that I had ever seen.

This little critter is none other than the Elm Sawfly (Cimbex americana). Larvae of this species can range from this yellow and green color to a sort of orange and pink tone and are distinguished by being the largest of the sawflies with a bold black stripe that runs vertically down its back, though the latter is more rare.

But what is a Sawfly?

They belong to the suborder Symphta of the overall order Hymenoptera—the very order that bees, ants, and wasps belong to. Now, you may have noticed how very wasp-like these critters look. Is it some form of mimicry? Not likely considering sawflies predate wasps evolutionarily a roughly 250 million years old. The name Sawfly is given to them based on the saw like structures on their ovipositors, specialized syringe-like appendages used to cut into stems and leaves to inject their eggs. Despite their fierce look, they do not sting.

There are nearly 8000 species of Sawfly sound the world, and most of them are herbivores, feeding largely on pollens and nectars. The one I had an encounter with is the largest Sawfly species in North America at roughly the size of a fun-size Snickers. Those adults, however, like most insect adult stages, are very short lived. We’re talking less than a week—just enough time to reproduce and lay eggs.

The eggs are injected into the stem or leaf of whatever the particular host may be in clusters of nearly 50 eggs each where they form a sort of gall. The host may very depending on the species. In the case of the Elm Sawfly, Elm is presumed to be the tree of choice—a once common neighborhood tree before the rise of Dutch Elm Disease—but other hardwood species and willows may be selected as well. After hatching 1-2 months later and feeding on the leaf, they will either pupate in the soil or in a cocoon (depending on the species) on their journey into their brief adulthood before beginning the cycle anew. In the case of the Elm Sawfly, they drop from the tree to the soil where they curl up and complete their metamorphosis overwinter, which is exactly what the two were doing this past weekend st the lake!

Sunday Fish Sketch| The Cookiecutter Shark

Meet the Cookiecutter Shark

Isistius brasiliensis

Cookiecutter shark head

It’s #Sharkweek so this weeks #SundayFishSketch theme is, well, sharks! So, here is my favorite—the Cookiecutter Shark. Also know as the cigar shark for that one time a sailor mistook it for a cigar and only realized their mistake after trying to light it up—kidding of course— Isistius brasiliensis is  shark of the family Dalatiidae. The genus name, Isistius, is based on Isis. No, not the terrorist group, but after Isis, the Egyptian goddess of light.

They inhabit warm, deep (about 2 miles down. So, deep for us, but on an overall oceanic scale) ocean waters around the world where they spend most of their time hovering in the water column like little creeps. This shark occurs in warm, oceanic waters worldwide. At dusk, they migrate vertically to the surface. They are fairly small in comparison to what one would typically think of when imagining a shark, at less than two feet maximum.

Isistius brasiliensis distmap

Perhaps the coolest adaptation of the cookie cutter shark is the way that it uses bioluminescence in tandem with its dark brown color to create two different visual manipulations. Possessing light-emitting photophores on its underside, the produced glowing green light helps to give the appearance of light entering the water from above when viewed from underneath. This is part of why they move up and down the water column depending on the time of day—to match the amount of light and not risk standing out like a neon take-out sign. The dark collar, on the other hand, is believed to act as a lure which mimics the silhouette of smaller fish. When a potential predator approaches the lure, the shark seizes upon the opportunity to quickly attach itself using its Steven Tyler lips and biopsies a 2 inch wide and 3 inch deep circular chunk out of the pursuer. In the words of Michael Gary Scott, “My, how the turntables…”. The cookiecutter also is known to travel in schools which only enhances this illusionary trickery.

It uses its top teeth to grip before retracting it’s tongue in a very clever way that creates suction before using the lower teeth as a bandsaw while it violently shakes and wiggles to retrieve its fleshy dumpling.Cookiecutter damage

In some parts of the world, virtually every dolphin (or other Cetacean) exhibits scars from this nightmare baker. Seals and other pinniped, large fish, and really any medium to large sized creature (including squids) are fair game—sometimes even humans (though that’s rare so don’t freak out, please.)

Sunday Fish Sketch| Freshwater Elephantfish

This #SundayFishSketch comes from Ichthyologist, Rene Martin. Visit her shop on InPrint to see more of her artwork or to order prints!


Meet the Freshwater Elephantfish

Mormyridae

Elefantenrüsselfisch
Mormyridae is an African family of 200 or so species in the biological order Osteoglossiformes. Oddly enough, but fitting in line with the peculiar and weirdly specific nature of systematics, Osteoglossiformes means “bony tongue” in Greek, so you can probably safely assume that these fishes do indeed have bony tongues.

If you think that’s interesting, you may just be a nerd. Coincidentally, so are these fish! They are known for having oddly large brains and high intelligence. In fact, there brain/body ratio is similar to that of humans! Just another lesson in why you shouldn’t judge a book by its cover.

The 200-ish species have extraordinary diversity, ranging in sizes between 2 inches and 5 feet.

Some other fun facts: the brain size is likely related to the fact that they have extraordinary bio-electric reception. This is because they tend to live in murky water and can only see red, so evolution had to throw them at least a bit of a bone. In fact, they generate an electrical field from specialized organs that they can use to better sense their environment. They are basically Matt Murdock. If you don’t know who that is, he’s Daredevil. If you don’t know who that is, we can’t be friends.

Also, they’ve only got one left gonad and tailless sperm. Odd, right?

So, there you have it. Elephantfish. Not elephants at all. Entirely fish. But definitely a bit elephanty in appearance. Sometimes.

The Dragonhunter

In the skies across Minnesota (and much of the eastern US and southeastern Canada, for that matter), roams a fierce and agile predator, capable of taking down prey you would never imagine—and some many wouldn’t dare to try at themselves.

Hagenius brevistylus, is a clubtail dragonfly known as the Dragonhunter, and is one of nearly 150 species found in Minnesota. Clubtails are the name given to members of the Gomphidae family consisting of about 900 species, itself. The Dragonhunter is by far the largest North American clubtail, reaching lengths near 3.5 inches.

The name Dragonhunter is one earned by reputation. Aerial ambush of darners and other clubtail is common, but other dragonflies aren’t their only kills. Dragonhunters have also been documented to prey on Monarch butterflies, feeding on select parts to avoid the highest concentration of toxins. If that isn’t impressive, dragonhunters have even been documented to pursue and successfully kill hummingbirds. Yes, hummingbirds. That’s surprising to a lot of people considering that hummingbirds are known for their speed and agility. They can flap their wings at 80 beats per second to hover in place and even fly upside down or backwards.

Dragonflies have that beat.

They are perfected flying machines. They can hover, fly sideways, upside down, vertically, and are the only insect that can fly backwards.

A dragonfly can accelerate at 3 Gs and make a near effortless turn at 9 Gs.

For reference, astronauts experience 3 Gs from a space shuttle launch. Most fighter jets can only pull up to 9 Gs vertically.

Still not resonating? A 150 lb person at 1 G weighs 450 lbs at 3 Gs.

There are a number of anatomical adaptations that allow for dragonflies to pull of these jaw-dropping maneuvers. In fact, the more closely you look at dragonflies, the more impressive and awe-inspiring they are. In fact, dragonflying—seeking out and identifying dragonflies—is a a fast growing hobby.

Rather than spoil everything for you right here, right now, I’ll leave you with this: we will be doing a podcast episode on dragonflies in the coming months, so stay tuned for more!

When a Spider isn’t a Spider

If you’re reading this right now, you might be realizing that we’re about to be playing a game of semantics (systematics, rather). For many, if it looks like a Spider, that’s all they need to know to shiver in disgust and engage in fight, freeze, or flight. It may be pretentious to dwell on the details, much in the same way as correcting someone on snakes being venomous and not poisonous (jeez, people. Venom is injected, and poison is ingested or absorbed! It’s not that hard). I’d imagine if you’d just been bitten by a harmful snake, the distinction would hardly matter to you (…but I also can’t let it go, and it totally does matter on some level).

This is another one of those things. However, the level of which it is important to make the distinction could be argued in different ways. We could go the scientific accuracy route (but they aren’t spiders!), or we could go the each organism is important in its own right and to know the difference is to have more understanding and more, maybe, appreciation route, or the “you don’t have to kill it/be afraid of it because it isn’t a Spider” route. But let’s be honest, you don’t need to kill or be afraid of either and if that’s the route of thinking you want to take, you probably couldn’t care less if it’s technically a Spider or not, right?

Often, somewhat disturbingly, called daddy-longlegs (even granddaddy-longlegs, which is like…what the expletive?), the critter you see above is called a Harvestmen—which is also disturbing.

First, the technicality: Harvestmen belong to the biological order Opiliones. They are arachnids, but they aren’t spiders. True spiders belong to the order Araneae. That being said, classification isn’t the only difference! Your stereotypical spider has two body segments sort of melded at the center. It looks sort of like it’s got a rubber band tightly coiled around its center, or like they’re wearing a Victorian era corset. Now you’re picturing a spider in a corset and you’ll never be afraid of them again. Thank me later.

Harvestmen, however, have a body that technically also has two segments but looks like just one. That middle junction between the cephalothorax (or head-chest) and the abdomen is far less distinct.

Harvestmen, much like you and I, have just two eyes, which means they see 4 times less than their spidery counterparts. That may seem like a disadvantage, but imagine being a spider and trying to find a pair of Ray Bans with 8 lenses. That’s why you don’t see any spiders in Top Gun. All of that is mostly accurate. I mean, technically some spiders can have no eyes, or really anywhere between zero and 8. Weird, right?

This is a Spider. He is cute.

Another thing, have you ever seen a Daddy-longlegs in a web? Nope. Not unless it was just visiting an Araneae pal. Harvestmen don’t have silk glands.

Oh, and another thing, and this ones a big myth-buster! Harvestmen, don’t have fangs, therefore no venom, therefore they cannot bite you and are absolutely not secretly the most venomous “spiders” on the planet like the legend would have you believe.

So, there you have it. Harvestmen are harmless, not-spiders that cannot do boo to you other than maybe scare you, which is a sort of boo…in a sense.