Hubbard Fellowship – When is a Gopher not a Gopher?

This post is written by Kim Tri, one of our two Hubbard Fellows for this year.  Kim is an excellent artist, as well as an ecologist, writer, and land steward.  As you can see, her drawings of animals are exceptional.

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13-lined ground squirrel.  Ink drawing by Kim Tri.

 

When it’s a streaked gopher!  That is the common name that I grew up with for the thirteen-lined ground squirrel (Ictidomys or Spermophilus tridecemlineatus).  Imagine my disappointment when I found out that actual gophers are 1) not closely related, and 2) look like this:

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Plains pocket gopher (Geomys bursarius).  Ink drawing by Kim Tri.

 

Pocket gophers are one of the few animals that I would describe as “ugly.”  Note: I do not use this word to describe pugs, star-nosed moles, aye-ayes, vultures, or a number of animals termed by most people as “ugly.”

As far as I can tell, the misnomer of “streaked gopher” (with streaked inexplicably being pronounced with two syllables) is unique to my family, as I have yet to find anyone who has ever heard of it who is not related to me.  “Striped gopher,” however, is a more common name, especially back in Minnesota, or the Gopher State (the MN Dept. of Natural Resources refers to it as the “Minnesota Gopher” on their website).  It is partially responsible for this unfortunate mascot.  University of Minnesota students will freely admit that mascot of Goldy Gopher was designed by someone who did not actually know what gophers look like.

Both thirteen-lined ground squirrels and pocket gophers are rodents, but the relationship ends there.  I. tridecemlineatus belongs to the family Sciuridae, which includes your familiar tree squirrels and chipmunks, and your less familiar (depending on where you live) ground squirrels, prairie dogs, flying squirrels, and marmots.  Pocket gophers belong to the family Geomyidae, which includes pocket gophers, end of list.  Both animals dig burrows and spend time underground, but since pocket gophers eat mainly roots and tubers, they need rarely come up to the surface and have taken burrowing to the next level.  They have oversize front paws for digging and lips that close behind their massive incisors, so that they can excavate with their chompers without getting a mouthful of dirt.  Their eyes and ears are small and weak because sight and hearing are not very important underground.  Thirteen-lined ground-squirrels, on the other hand, are part of the group of spermophiles, or “seed-lovers,” (though they eat a lot of insects as well) and consequently spend much of their time foraging aboveground and are less specialized for burrowing.  They’ve kept the squirrel’s nimble forepaws as well as good eyesight and hearing for detecting predators and prey alike.

I’ve always been enamored of thirteen-lined ground squirrels.  I mean, look at that face.  Then look at the clever little paws, sleek body, and intricate design.  Growing up, I could watch them sometimes from the kitchen window, and can do the same here.  We share the yard with a family of them, and it delights me to see them.  They build little tunnels through the pile of grass clippings that have accumulated by the walkway and use them as cover while they forage in the backyard.  Their favorite pile seems to be right outside of my window, so I have had plenty of opportunity to watch the little ones playing and growing throughout the summer.  They never paid me much heed, so I just assumed that they couldn’t see me through the window screen.  After spending quite a while standing not very still within a few feet of a foraging ground squirrel, I have since concluded that they simply don’t care about people.  They know that they can be underground before I can even bend down to snatch them.

Disclaimer: I am not bashing pocket gophers.  Their adaptations for burrowing make them pretty cool, at least to me, as do their “pockets”—cheek pouches for carrying food which extend all the way onto their shoulders and can be turned inside out.  I just think they’re ugly.

But, you know, the more I look at them, the more I see some cute in them.  I mean, look at that face.

pocket gopher head

 

P.S. If you want to see how Minnesotans feel about real gophers rather than people in striped gopher costumes, look up Viola Gopher Days, which take place near my home town.  I personally have never been and can’t decide whether I find it grisly or folksy.

Hubbard Fellowship Blog – Mummy Wasp!

The following post was written by Evan Barrientos, of our two Hubbard Fellows for this year.  Evan is a talented writer and photographer, and while you’ll get the chance to see some of his work here during the next year, I also encourage you to check out his personal blog.

How many naturalists does it take to spot a parasitoid? In this case, two. While we were harvesting seeds in a wet prairie, Chris spotted this caterpillar. He noted that it seemed to be mimicking horsetail (Equisteum sp.), a very common wetland plant, for camouflage. That was a really interesting idea, but it turns out be far from the truth, and you’ll soon see why.

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At first it seemed that this caterpillar was mimicking horsetail (Equisteum sp.), but can you spot the real culprit of this caterpillar’s odd appearance?

Upon a closer look, I noticed that the caterpillar was honeycombed with holes. This  caterpillar wasn’t using camouflage; it had been parasitized! Did you know that there are forty to fifty thousand species of wasps so small that they are almost invisible to the naked eye? They are called Braconid wasps, and they have a fascinating life cycle. Nearly all Braconids lay their eggs on or inside another insect (called a host), which are often caterpillars. After the eggs hatch, the wasp larvae eat the host’s insides, pupate (turn into adults) inside the body, and chew their way out as full grown wasps! Insects that do this are called parasitoids. While I was taking photos of the dead caterpillar, Chris made an even better observation: there was one last wasp still emerging from it!!!

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A Braconid wasp emerges from its caterpillar host. Keep reading to learn exactly what species they are.

It was awesome to witness and document a Brachonid wasp in action, but I wanted to go further: I wanted to know what species these two insects were. As a naturalist, I love learning about tiny and obscure organisms like this wasp. It just blows my mind that so much information exists about such unappreciated species if you can only identify them. When you learn a species’s name, it goes from a speck to an encyclopedia. So I posted this photo to Bugguide.net and an incredible entomologist (insect scientist) suggested that this might be a Stigmata Mummy Wasp (Aleiodes stigmator) feeding on a Cattail Caterpillar (Simyra insularis). I did a little more research and found this publication on Aleiodes wasps. I learned that as Aleiodes larva go about eating their host, they line the caterpillar’s insides with a light silk. Eventually, the caterpillar dies and shrivels up, which is why the wasps are called “mummy wasps.” Aleiodes larvae chew a hole through their host and secrete a substance that glues it in place while they finish eating and pupating. Eventually, they chew their way out of the host and emerge as adult wasps.  If this all sounds gross to you, at least consider that mummy wasps and countless other Brachonids are important pest predators. Mummy wasps help keep gypsy moth and tent caterpillars in check, and several species of parasitoid wasps are sold to protect crops ranging from corn to tomatoes.

It turns out that each Aleiodes species makes a unique mummy. I went through the pictures in the publication I was reading and found one mummy that closely resembled my specimen (described as “appearing as though pelted evenly by shotgun pellets”). Sure enough, the guide listed the wasp as Aleiodes stigmator and the caterpillar as Simyra insularis! From there I learned that A. stigmator is the oldest known Aleiodes in North America and was discovered by the first American entomologist, Thomas Say, in 1824. Say thought the wasps’ exit holes looked like stigmata in the hands and feet of Christ, and so named the species “stigmator.” Despite having been discovered long ago, this species has never been carefully studied and many basic facts about it are still unknown.

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When you look at the holes in this caterpillar, do you think of the stigmata on the hands and feet of Christ? I sure didn’t, but the entomologist who discovered this wasp somehow did.

I don’t know what’s more amazing, wasps that eat their way out of caterpillars or people who can identify them from a single photo.  It never ceases to astound me how every living speck of an organism has such an interesting story behind it. This process of stumbling upon mysteries and discovering their secrets is a large part of what drives me to spend so much time exploring nature. There’s just so much coolness out there!