insects

Answer to the Monday Mystery

Yesterday’s challenge required a fair amount of knowledge about the peculiarities of wasp development and morphology. Thus, I’m pleased the answers surfaced so quickly!

Here is a color photograph of the same species, a braconid wasp from Costa Rica:

Hym_anatomy

Counting abdominal segments was tricky for two reasons. For one, most Hymenoptera have the first true abdominal segment fused to the thorax, so that functionally and visibly it is not part of what appears to be an abdomen. If this seems an obscure concept, I recommend watching ant, bee, or wasp brood in metamorphosis from prepupa to pupa. In many species, we can actually see the first abdominal segment move up and glom on to the thorax. In any case, abdominal segment counts in wasps start with  what appears to be the back of the thorax.

Secondly, this particular family of wasps, Braconidae, has the dorsal plates of abdominal segments 3 & 4 fused. Thus, to count to the labelled segment in the challenge, you have to both recognize the fusion of abd 1 with the thorax, and abd 3-4 with each other.

Points are awarded as follows: 5 to Mr. I Love the Ants for counting correctly, 2 to Katherine for picking the family (though, not full credit for lack of supporting characters),  1 to Matt P for noting the fusion of 3&4, and 3 to Matt Bertone for noting the characters supporting the familial identification.

We really don’t know why monarch butterflies are disappearing

Monarch butterflies- the most iconic of American insects- have declined to perilously low numbers this winter:

MonarchDecline
Total Area Occupied by Monarch Colonies at Overwintering Sites in Mexico. The decline is statistically significant, and numbers that were bad 20 years ago would be considered good today.

This is horrific. We’ve lost over 80% of the butterflies.

The waning of our monarchs has lead to the inevitable speculations as to the cause. Which is fair enough. But I’d like to point out the ideas are just speculation.

No one really knows why Monarchs are declining, or why 2012-13 is such a bad year. 

Lacking the proper experiments to determine how various factors affect the butterflies, and lacking solid data about their milkweed food sources, assigning causes to the phenomenon simply isn’t possible. The monarchs are disappearing. That’s all we can say with certainty.

Candidate causes abound, though.

  • -The severe heat and drought of 2012 across much of the monarch’s summer range may have reduced the monarch’s host plants and stressed the remaining animals.
  • -The extensive use of agricultural herbicides in conjunction with herbicide-resistant crops could be eliminating the monarch’s food supply, perhaps causing the gradual decline over the past 10 years.
  • -The destruction of milkweed habitat for corn ethanol production, also a gradual new phenomenon in the past 10 years, could reduce the monarch’s food.

 

I had always kind of assumed we’d be able to blame the Mexicans for the eventual extinction of our treasured monarchs. After all, our eastern butterflies converge each winter on a fragile, postage-stamp patch of a forest near Mexico city. It wouldn’t take more than a couple days for los bulldozeros (or, whatever) to knock out the winter refuge for the entire monarch population. But since the Mexicans appear to be upholding their end of the migration, this loss may be on us.

People who care about North America’s most famous butterfly should be treating the decline as an emergency. One more bad year could spell the end.

In particular, we need two big things. First, we need the science. This means money to ramp up monitoring & experimentation. A lot of it. And soon. It’s hard to know how to bring the monarchs back without knowing why they are disappearing. Second, we need milkweed planted. A lot of it. And soon. While we don’t know why the monarchs are declining, the most plausible explanations involve the butterfly’s food sources, so reversing milkweed loss should be an obvious step.

I was going to add a photo of a monarch to this post, but the whole thing is just too damn depressing.

Is “Bedbugs” one word or two?

Cimex26

According to Google’s ngram viewer, a measure of word frequency in scanned books, “bedbugs” as a single word is used far more frequently:

ngram

Yet Google trends, which measures search terms, reports the converse:

trends

So authors are writing about bedbugs, but the general populace is searching for bed bugs.

Which is correct?

The convention among American entomologists is to treat common names where the insect category (“bug”) is correct as separate words, but to combine names into single words when the insect category is incorrect. Example: the house fly is really a fly, but a firefly is really a beetle. Since bed bugs belong to Hemiptera- the true bugs- then in our country, at least, the appropriate spelling is bed bug as two words.

Score one for the internet.

 

Bark Lice Are Ruining Christmas

Poor Laura Beck. The stockings are hung, the egg nog is mixed, the gifts are wrapped, and all is set for a warm and happy holiday EXCEPT OMG TEH BUGS ARE RUINING EVERYTHING:

…it turns out the beloved Christmas Pine doubles as a half-way house for mites, moths, spiders, and something disgustingly named ‘bark lice’. Puke/Shudder.

I know many of us grew up with Christmas trees — shit, some of us have these terrifying beasts in our apartments as I type — and we’re all fine (I THINK), but that’s not going to stop me from taking ten scalding hot showers and febreezing the whole damn thing.

(from jezebel)

Who are these Christmas-destroying monsters?

A herd of bark lice in Tolima, Colombia.

I think of bark lice as tiny buggy bison. These pudgy little insects graze across vast plains of tree bark, munching on lichen and fungus, and generally minding their own business. Bark lice do not bite people, they do not carry human diseases, and they pose no risk to structures. They are about as innocuous as an insect can be.

The fate of most bark lice roused from winter hibernation by an unplanned trip to Laura Beck’s living room is death. They are fragile creatures, and the artificially dry environment of a heated home will suck the moisture right out of them. An inadvertent rendezvous with a Christmas tree should be a far more traumatic experience for the bugs than for the holiday revelers that host them.

Unless, of course, one has a pathologically irrational fear of arthropods, in which case the proper treatment for bark lice isn’t bug spray but an appointment with a relevant mental health professional.

Answer to the Monday Mystery

Xenox trigrinus

In the several-year history of the Monday Mystery, few people have so thoroughly nailed the correct answer as Joel Kits:

Bombyliidae: Xenox tigrinus

Longitudinal veins from the top right are R1 in extreme corner, R2+3, R4+5 (Rs before R2+3 splits off at left and splitting into R4 and R5 at right), M1, M2, and CuA1. Crossveins are r-m at top left and dm-cu closing cell dm.

By my count that’s 10 points to Joel for being the first to the correct taxonomic answer, plus 8 venation bonus points, for 18 total. That’s going to be hard to beat for the monthly tally.

And, two bonus points to BioBob for keeping me company in the lonely first hours of the challenge.

The daily life of an entomologist

I know some of you young folks are thinking of becoming professional entomologists. That’s a fine career choice. Intellectually stimulating. Full of adventure and intrigue. Before you decide to embark on such an unusual professional journey, though, you’d do well to know how full-time entomologists spend their days:

The daily life of an entomologist. In our very wildest dreams.

Ha! Just kidding.

For a glimpse at the actual daily activities of a university entomologist, have a look at McGill professor Chris Buddle’s schedule:

Answer to the Monday Limerick: Horntail

Tremex columba (Urbana, Illinois).

As many of you surmised, yesterday’s limerick referred to Siricid sawflies, also known as horntails. These insects are wasp-like in appearance, partly because they belong to the same order as wasps, Hymenoptera, and partly because the coloration of some species has converged on wasp-like stripes.

Horntails belong to an older radiation, though, one that never developed the characteristic wasp waist nor the typical wasp carnivory. Horntail larvae feed on dead wood, and the fierce appearance of the adults belies a gentle disposition. The long “tail” cannot sting, being merely an egg-laying structure.

Tremex columba – the pigeon horntail (Urbana, Illinois).

Points are awarded as follows: 5 to Chris Murrow for being the first to pick the suborder, and 5 each to Josh King and Jesse Hardin for being roughly tied here and on FB for guessing Siricidae.

 

A battle-scarred mantis

Sometimes, blemishes on a subject tell a story. I didn’t notice the pair of thick scars on the mantis’s face until I brought the images up for processing.

Tenodera sinensis

While we can’t know for certain what happened, it looks like an old prey insect fought back. Perhaps a carpenter bee managed to grab hold of her killer’s face, or an ant retaliated. In any case, this insect isn’t a picture-perfect specimen. It’s more interesting than that.

Incidentally, the image is among the most heavily photoshopped files I’ve ever uploaded to my galleries. It is a focus-stacked composite of two photographs taken at slightly different focal depths, combined manually using the clone tool in photoshop. The focus-stacking technique produces an optically impossible result, yet one that is pleasingly crisp, with the illusion of being larger than life.

Here are the unedited originals:

These photos were taken at different focal planes.