Sunday, July 10, 2011

A "chameleon" frog and a murderous "bumblebee"

We had a great time this weekend at the Midwest Native Plant Conference, and major props to all of the organizers of that affair. As usual, all the details were well thought out and executed perfectly. Stay tuned for info about next year's event.

On the conference's final day, Sunday, we have field trips. These forays visit natural areas rich in biodiversity and native flora, so that conference attendees can see native plants in their natural haunts, and better learn how they interact with the rest of the world. I was one of the trip leaders at the legendary Cedar Bog and we saw lots of noteworthy native plants. But as usual, the trip morphed into a natural history free for all and non-chlorophyll-bearing organisms were not ignored.

This morning's expedition was helped greatly by the presence of Steve McKee, Cheryl Harner, and Nina Harfmann. All are great naturalists and all know Cedar Bog's various charms well. But a New Sheriff came to town, and we were delighted to have him along. Derek Hennen was the conference's scholarship recipient; he's a student at Marietta College. Check his blog, RIGHT HERE. Turns out Derek is a heckuva entomologist and overall naturalist, and we probably learned more from him than he from us! The two critters featured here were spotted by Derek.

Gray treefrog, Hyla versicolor. It's that "versicolor" in the scientific name that is a key point of interest with this little suction-cup footed tree climber. I shot the above photo in Indiana a few years back. The frog is stuck to the bark of a black oak, and is supremely confident in his ability to blend with his surroundings. But as we shall see, these wondrous little amphibians are truly versatile in their coloration.

Same frog, different color. The aforementioned Derek spotted this "gray" treefrog ensconced among the foliage of a white cedar, and doing a pretty darn good job of matching its surroundings. Certainly nothing like the previous photo of a gray treefrog doing its best to mirror the bark of a crusty gray tree. Note the pale Missouri-shaped patch below the eye. That's a constant, no matter what color our chameleofrog decides to be.

There is another essentially identical species, the Cope's gray treefrog, and I once posted about that one HERE.

Ah, the bumblebee, a soft and fuzzy loveable insect if there ever was one. Black and yellow Bombus bumblebees are a fixture around flowering plants, busily rushing about sucking up nectar and getting their "fur" thoroughly doused with pollen. Bumbling off to another plant, they complete the pollination process, hundreds of times a day.

Bumble Bee

by CJ Heck

Today I saw a bumblebee.

He was on a pretty rose.

I leaned in to look at him,

and he stung me on my nose!

I wasn’t gonna squish him,

only watch and see …

but I’ll never get THAT close again

to a grouchy grumble-bee.

Well, Poet Heck ain't seen nothin' yet when it comes to dangerous "bumblebees"!

We were strolling down the boardwalk at Cedar Bog when a muted roar arose behind us. The stragglers had found something cool! We rushed back to discover that sharp-eyed Derek had spotted this bumblebee that is decidedly NOT a bumblebee perched on some shady foliage. We saw through its act instantly, and I was particularly elated as only once before had I had opportunity to fix one of these in my camera lens, and I muffed the shots.

We move in and things get creepier. Yes, the beast clearly resembles a bumblebee, but things aren't quite lining up. Sure, the body is big, plump and banded in black and yellow fuzz. Its abdomen curves downward like that of a bee, and even the wings cant backwards in bumblebee fashion, although they look a bit longish.

It's a robber fly! Not even closely related to a bee, but in an entirely different family.

The jig is up when we take a close look. The very short antennae, big widely spaced goggle eyes, and especially that menacing-looking syringelike proboscis on its snout mark this animal as a robber fly. It is one of many species in the genus Laphria, all or nearly all of which are absolutely remarkable mimics of the large fuzzy bees that we know so well.

CLICK HERE to read a column that I wrote recently for the Columbus Dispatch that delves into the workings of the remarkable robber flies. Robber flies are highly predatory and big ones such as this Laphria bee mimic can bring down prey as big as themselves. When a victim is spotted, the fly shoots out in pursuit - believe me, this robber fly can fly the socks off a real bumblebee - and engulfs it prey. A quick jab to the thorax with that menacing proboscis and it's curtains. The victim is injected with chemicals that quickly immobilize it, and rapidly liquefy its innards. Once a milk shake-like consistency had been reached, the prey's contents are sucked out via the fly's proboscis just as you would slurp the contents of your shake with a drinking straw.

Why look like a bee if you are a fly? There are a few theories. One has it that by resembling a bumblebee, the fly can more easily infiltrate the real bees as they work over flower patches. The preoccupied bees are unlikely to notice the interloper. This subterfuge puts the fly in an easy position to attack and kill one of its lookalikes.

Another has it that the fly may help itself to avoid predation by other bigger tougher beasts by looking like something that sports classic back and yellow warning coloration, and is a known stinger. If that's true, this plan backfires upon occasion. The ferocious red-footed cannibal fly, our largest robber fly in these parts, preys on bumblebees and would probably have no compunction about grabbing a Laphria mimic bee.

I think the first theory makes the most sense. Most bugs probably don't pay much mind to bumblebees as they are not predacious and insects have been conditioned not to fear them. And bumblebees are abundant and ubiquitous, and 999 times out of a thousand they really are bumblebees. So, by resembling one of the harmless nectar-seekers our robber fly can lurk in the corners, ignored and dismissed by the other bugs as just another harmless bee. Until it roars out and lays waste to the unwary and unsuspecting bug that didn't pay ettention to details.

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1 comment:

Cathy said...

Love the "gray" treefrog that has been on my patio since June. I wait in the evening to hear his "trilling." Haven't found many of his offspring in my pond, even though his calling is answered.