The Bug Geek

Insects. Doing Science. Other awesome, geeky stuff.

Category Archives: Hymenoptera (Bees, Wasps, Ants)

Forgotten Photo Friday: death of a butterfly

This photo, while neither compositionally nor technically lovely, captured one of the more dramatic insect-insect interactions I’ve ever encountered:

Polistes sp. with Monarch Butterfly (Danaus plexippus)

A large wasp (Polistes sp.) was dangling by the slender tarsal claws of its two hind legs, clutching a frantic and struggling newly-eclosed Monarch butterfly (Danaus plexippus).  Its wings still soft, wrinkled and useless, the butterfly could do little to ward off or flee from its attacker. It valiantly tried nonetheless, twisting its body and kicking as the wasp hung on with great determination.

After several minutes, the weight and motion of they prey caused the wasp to lose its grip on the blade of grass, and both tumbled to the ground, still in their deadly embrace.  I left the scene then, feeling fairly certain of the butterfly’s fate…

(Photo taken at the Shaw Nature Reserve in Missouri).

A weird, wingless discovery

One thing I love about sorting my trap samples is that I never know exactly what I’m going to see! Add to that the novelty of specimens from the far north, and the inherent diversity of insects, and it’s pretty much guaranteed that I’m going to see at least a few new-to-me species every time I sit down at my lab bench.

This term I’ve had an undergraduate student volunteer, Michael, working with me.  He quickly demonstrated that he’s not only interested but also talented, progressing from sorting to pinning and pointing specimens (a task I’m notoriously anal about and rarely relinquish to others – everything must look *just so* – but Mike has proven up to the challenge) in a few weeks.

He’s also got what I’d call a “good eye”.  While he may not know all the formal taxonomic names or anatomy of everything, he’s been quick to pick up on the visual cues and patterns of different groups of insects, and often points out interesting new things he finds in the samples he’s working on.

The other day, he looked up from his dissecting microscope and asked, “Do all wasps have wings?” He had been taught, you see, that two pairs of membranous wings was one of the defining characters of the wasps he was to extract from his samples.  “This looks like a wasp, but it doesn’t have wings.”  I came over to his station to take a peek and saw this:

Gelis sp., a wingless female parasitoid (Ichneumonidae)

A wingless female parasitoid wasp. Photo by Katie Sim (because I am useless at using our lab microscope camera and Katie can take great photos of tiny things like itsy-bitsy spider genitals. )

I saw that he had correctly nailed this critter as a Hymenopteran, and that, indeed, it had no signs of wings.  In a moment of blinding genius, the first words that fell out of my mouth were: “It’s an ant!”  Then, “No, wait…”  Although the tiny, reddish, long-legged animal did rather resemble an ant, the abdomen, mouthparts and antennae were all wrong. A wingless wasp it was! How cool!  I shared Mike’s excitement over the discovery, as this was a first for me as well.

I did some Googling and Bug Guide searching, and found that a number of parasitic wasp groups had wingless females.  (I also read that many of these were ant-mimics that would sneakily attack ant-tended hoppers and their nymphs, so felt somewhat better about my earlier ID gaffe).  Since there were too many possibilities, I called in the reinforcements: the post-doc in our lab also happens to be our resident wasp expert. Laura kindly agreed to take a look at the tiny critter and quickly confirmed her initial suspicions: it’s a member of the family Ichneumonidae, of the genus Gelis.  And that’s about as good an ID as we’ll get, because apparently the Gelis sp. group is ridonculously difficult to pick through.

As far as their diet goes, Laura had this to say: “They attack a variety of things, generally things in silk cocoons.  So, they can be hyperparasitoids on cocoons of Ichneumonoidea, or primary parasitoids on spider egg sacs or small Symphyta and Lepidoptera cocoons”.  So much for my maybe-it-looks-like-an-ant-so-it-can-attack-ant-tended-hoppers theory.  This wasp’s winglessness may therefore be a reflection of her preferred food sources: egg sacs or cocoons attached to low-lying vegetation are perhaps easier to access by land, rather than by air.  By not “wasting” energy on the development of wings or on flight, the female wasp might be able to devote more energy to the production of her eggs and eventual offspring.

I love this little discovery in part because parasitoids are awesome and wingless parasitods are extra-cool.  But I think I love it MORE because it involved the combined efforts of four people to pull all the pieces together (thanks Mike, Katie and Laura!)

Forgotten Photo Friday: Carpenter ant and membracid

Love is in the air

So I was driving along, enjoying the scenic country landscape along the last bit of my route home, when suddenly, “SPLAT”.

Then, “SPLAT.” “WHACK.” “SMUCK.” “POW-POW-POW-SMUCKA-SPLAT.”

I found myself driving through a veritable fog of smallish flying insects.  What on earth?

I soon arrived, hauled my groceries into the house and went to sit in the backyard with my wife for a spell; I found myself in the middle of another swarm.  The angle of the early-evening light was just right for me to see the twinkle of light passing through hundreds of pairs of wings above my neighbour’s hay field; then I noticed more insects apparently rising from a corner of our lawn, up past the fence and into the great beyond.  I reached up and snagged one critter as it flew overhead, and finally solved the mystery: we were in the middle of a swarm on ants on their nuptial flights!

Ready to find a mate!

Now, I’ve seen winged ants before, but never in numbers like these.  Even more fascinating, the phenomenon lasted for a total of maybe 15-20 minutes.  One minute the lawn was milling with little winged  critters and they were floating up from the grass by the dozens; the next minute all was still and I had very little luck finding even a single ant. (Our resident Backyard Toad, however, had come out of his hiding place behind our fence and was keenly spying – and gulping down – the stragglers).

Here’s a little clip of one small patch of our backyard.  I have no idea what kind of ants these are.  Orange-ish ones???

Sneak Attack! (Goldenrod crab spider, Misumena vatia)

Our gardens provide an excellent close-by space for bug hunting.  Most days I do a “tour of the grounds”, inspecting flowers and leaves for interesting critters.  So the other day I was poking around a patch of purple coneflowers, when I saw this:

A bee head...upsidedown?

A little bit of bee peeking out from behind the pink petals.  Something was all wrong, though.  First, it wasn’t moving, and secondly, it was peeking out head-first.  Very odd.  Crouching down to get a better look beneath, the problem quickly became apparent:

Goldenrod crab spider with prey

A well-hidden goldenrod crab spider (Misumena vatia: Thomisidae) had snatched up the unsuspecting foraging bee and was now enjoying a well-deserved snack.

As I photographed the scene, I noticed a pair of very small flies circling nearby.  They occasionally landed on the bee.

Little...Muscids? Doing...something?

I’m really not sure (little help, fly guy or other fly guy?) but I think they’re little Muscids of some kind.  If I had to guess, I would say that they were feeding on the pollen grains clinging to the bee’s hairs…I can’t think of what else they’d be doing…does anyone else care to venture a guess?  (Ooh, I’d take guesses on the ID of the prey, too!!!)

***Edited to add: read the comments (Dooooooo it.  Do it now). Morgan from Biodiversity In Focus (aka “Fly Guy #1) has some great insights here!

***Edited to add #2: Micheal has offered another really interesting suggestion, and a nice pic to boot (in other words, if you haven’t read the comments already, you really should now).

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