The Bug Geek

Insects. Doing Science. Other awesome, geeky stuff.

Tag Archives: wasp

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).

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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!)

Ichneumonid wasps

I don’t know what it is with me and wasps in stumps lately: I’ve never noticed them in the past, and now I’m finding all kinds of them.  This gorgeous, slender female Ichneumonid wasp woke quickly once I disturbed her.  Her long, banded antennae quivered non-stop as they were bombarded with chemical and tactile signals from the fresh air.  

She climbed to the edge of the piece of log where once she slept and flexed her wings…once…twice…

and then she flew off in a startlingly graceful arc to a moss-covered stump several feet away.  The one thing these images do not capture (much to my great dismay) is the gorgeous deep midnight blue colour she sported over her entire body.  It gleamed with hints of rainbow hues in the sunlight.  I wish I could have shared it with you.

In the same log, her cousin continued to doze.  Antennae ramrod-straight, body motionless, her lovely burnt-orange body was accented by a burgundy thorax and pale yellowish spot at the point where her iridescent wings met.

Until this year, I really had no idea that tiny, dark crevices in dead wood were such great places to find beautiful wasps.  A wonderful discovery, if you ask me!

A Queen sleeps in the woods

I woke her, ever so gently, and only for a moment…

and then I tucked her back into bed.

Although she rests now, this bald-faced hornet (Dolichovespula maculata)  has a big job ahead of her in the spring.  With a belly full of eggs fertilized last summer, the warmer weather will soon call her to rise and begin constructing a new wood-paper nest and to lay the eggs that will eventually become her first workers.  Her daughters will then take on the task of enlarging and defending the nest, collecting food and eventually, feeding the next brood of young.

There was something about the stillness of her, combined with her sheer bulk (she is a very large insect, nearly 30mm in length), that seemed both terrible and lovely, and somewhat awe-inspiring.  I was honoured to have been able to take a quiet moment to appreciate her beauty.

Wasp revealed! (And AIF #2!)

First, if you haven’t yet, go look at An Inordinate Fondness #2.  Hurry quick!  Do it now!  Beetles!  And Beatles!  ZOMG!

Next:

I finally have a name to go with the face of my wife’s mystery wasp!

Dr. Bob Carlson, specialist of Ichneumonidae and BugGuide contributer, has identified her as Aoplus confirmatus.  I am quite pleased that she is the first record of this species on BugGuide.  Yay!

Armed with a name, I have Googled, and I have learned.  Behold:

Adult hibernation in wasps is generally an oddity, but it is a characteristic of a number of Ichneumonid species (the parasitoid wasp family to which our pretty belongs). 

If you encounter a hibernating Icheumonid, you can bet your bippy it’s a female; the males almost always die in the fall after mating, and gravid (egg-filled) females wait until the spring to deposit their eggs in a host.

These pretty parasitoids can be quite picky about their winter digs…for example, some prefer hidey-holes under loose bark, others under moss on felled trees, and some like cavities in stumps created by other insects.    On a larger scale, they seem to like more sheltered, low-to-the-ground terrain, rather than open spaces.

The frequency with which it is possible to encounter these interesting adult wasps during the cold, bug-less months makes them an ideal wintertime study subject.  As a matter of fact, a wasp enthusiast may have more luck tracking down some species as they slumber in their hibernacula than during warmer months using more traditional trapping methods (sweeping, pan traps, Malaise traps etc.)

And lastly, a personal aside for Jason: “Yay!”

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Cool (ha!) Reference:  Hibernating Ichneumonidae of Ohio (Dasch, 1971)

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