April Taxonomy Fail: The Naming of Pests

I run across so many insect bloopers and taxonomy fails I thought I’d start a little running feature on them to go with my ever enlarging file of Things That Are Not Fire Ants.  I’m thinking monthly?  Biweekly?  Whenever I feel like it?  We’ll see.

Anyway, today’s little gem is brought to you by Aspect Home & Pest, who really ought to know better.  I present to you:

“Ticks”

“But wait!” you say.  “Those are ticks. They are eight-legged dorsoventrally flattened blood-sucking arachnids.”

Yes.  Yes, they are.

But keep on scrolling down the page.  I present to you:

“Fleas”

“Um,” you say.  “Those are still ticks.  Fleas are six-legged laterally flattened blood-sucking insects.”

That is also true.

Whoooops.

Don’t look now, but we’re surrounded: the Springtails

Close up of a pretty blue springtail in the detritus of a dead fire ant colony.

A few of my smaller, failing fire ant colonies are infested with tiny crawling things.  In the spirit of curiosity (and getting these things out of my lab colonies) I finally put them under a scope to try to figure out what they were.  Turns out they’re actually rather pretty close up.  They’re also a member of what may be the most abundant arthropod in the world.  Springtails (class Collembola) are tiny, easily overlooked, and almost everywhere.  Primarily detrivores and microbe-eaters, they mostly inhabit leaf litter, with an average square meter of topsoil containing upwards of 40,000 individuals (Hopkin 1997).

Slender springtail on its side with furcula visible.

Collembolans are one of three groups of hexapods (six-legged arthropods) that are not considered part of class Insecta.  Unlike the later derived insects, they are wingless and entognathous (have mouthparts retracted into the head).  Collembolans take their common name “springtails” from a unique bit of morphology that allows them to jump 20 to 100 times their height in a fraction of a second.  This structure, a long forked prong called a furcula, tucks under their body into a clasp and releases like a spring, launching them into the air.  In person it looks sort of as if they are vanishing and appearing elsewhere in the tray, like tiny buggy teleporters.  It is easy to understand why these organisms are sometimes claimed as the source of delusory parasitosis–a condition which cause people to falsely believe they are infested with parasites.

Slender springtail adult and nymph (Seira bipunctata). Look how adorable they are!

These particular springtails have the characteristic appearance of the family Entomobryidae, the slender springtails.  I was curious to know more about the infestation of crawlies eating the dead crickets and ant detritus in my lab so I also threw a picture onto BugGuide, where I was rewarded with a species ID a day later.  They are Seira bipunctata (det. thanks to Frans Janssens).

Springtail nymph with furcula extended.

Unfortunately, little non-taxonomic information appears to be available on these guys, although the genus Seira is distributed throughout North America, as well as most of the world.  My personal observations are that they appear to be detrivores, fairly active, and the mid-sized ones seem to leave their furculas extended and also wiggle them at me when poked. I don’t know; poking things to see what they do is pretty much my go-to technique as a scientist.

Slender springtail (Entomobryidae: Seira bipunctata).

One final note:  One of the scientific papers I read while researching this post used the phrase “the collembological community” to describe springtail researchers.  “Collembological” is now my new favorite word.

When Bugs Bite Back

A horse fly perches on a tree.

The family Tabanidae derives its name from the latin word tabanus, meaning “horse fly.”  I’ve noticed that observing which orders and families of insects take their latin names from actual latin or greek words for the insects (e.g. roaches, lice, ants) tends to give an idea of which insects have historically made the biggest nuisances of themselves.  Chalk these biting flies up on that list.

I like horse flies because they turn the tables on entomologists.  I have had several experiences wherein it was unclear just who was hunting whom.  It generally winds up with me flailing wildly with my net while running in circles to try to stay out of reach of the fly.  The lady fly is, after all, on the lookout for a tasty blood meal to grow her eggs with, a meal she will secure by slicing open a wound with scissor-like blades on her proboscis.  She’s also way faster and more agile than me.  It’s extremely disconcerting.

Horse and deer flies can be distinguished from other flies by their large eyes, their enlarged third antennal segment, and by the pair of “Y” shaped wing veins that enclose the wing tip.  Male horse flies, which do not blood feed, generally have eyes that meet in the middle of the head, unlike the lady in the picture above, whose eyes are set apart.

As a side note, my backyard is suddenly full of stable flies, a house fly-like muscid fly which rabidly attacks my ankles when I venture outside.  Ow.  If I’m overcome with masochism I’ll even try to get pictures for y’all.

Cunning Caterpillars

A luna moth caterpillar with an Argentinean peso for scale.  For some reason this was the only coin I could find.

I wasn’t going to do another caterpillar post but I haven’t had a chance to key out the springtails for the other post I’m working on, so here you go.  As you can see, they’re still growing like fiends.  Also, I haven’t been to Argentina in two years; how is that peso still in my wallet?

Yesssssss….. Exceeeeellent.

Overnight all my caterpillars turned into evil masterminds.  Or so it would appear.  Just days before they all appeared to be perfectly innocuous little caterpillars who sometimes tried to chew off their siblings’ faces.  But now just look at that caterpillar!  He’s clearly up to something.

Someday soon I will be a beautiful butterfly.

I can’t find much in the literature on this reared-head posture–which appears to be pretty common in this family of caterpillars–but popular opinion around the internet seems to be that this is a defensive/camouflage posture to make the caterpillars look less like food to hungry predators.  They do resemble little green twigs, although it’s kind of creepy when they’re all lined up in a row staring at you.  It also puts them in a good position to employ another defensive response: clicking and puking!

A luna moth caterpillar in feeding posture on a partially eaten leaf.

When disturbed, late instar luna caterpillars and many other bombycoids (silk moths, hawk moths, emperor moths, etc.) make an audible “clicking”, “squeaking” or “crackling” noise with their mandibles and then regurgitate noxious chemicals.  The regurgitant is apparently broadly deterrent to both vertebrate and invertebrate predators:  in the kind of science experiment I love, Brown et. al (2007) demonstrated that both ants and mice reject food treated with caterpillar puke.

I haven’t heard mine click, but they have spewed brown goop all over when I change their leaves.  I chose not to eat them, so it was apparently an effective deterrent for human predators as well.

>>The Luna Moth Saga

Cute, fuzzy, cannibalistic

Newly hatched caterpillars.

The luna caterpillars are still rocking along so far.  They eat like hungry hungry hippos so it’s a race to keep them well-foliated.  I’ve been making lots of trips down the street for more walnut leaves.  But how can you not love these sweet little faces?

Sweet little face.

Fun story:  Today when I was snipping of bits of leaves to move the caterpillars to fresh foliage I accidentally snipped one caterpillar in half.  (I did mention I’m terrible at caterpillars.)  Anyway, the two nearest  caterpillars immediately started chowing down on their dearly departed sibling like it was the best thing since bacon ice cream.  Then, apparently, they got so carried away they started trying to eat each other, and for the first time in my life I got to break up a caterpillar fight.

I’m fuzzy like a teddy bear!  And may also try to eat your face!

My caterpillars are a bit overcrowded at the moment, so I’m planning to spread them out across a few more containers.  On the other hand, I suspect if I don’t they’ll take care of the issue for me.

First this quarter, next the WORLD.

>>The Luna Moth Saga