The Milbs Are Back

Most years mourning cloak butterflies signal spring’s arrival. This year it’s Milbert’s tortoiseshells.

The first one appeared a few days ago, while snow was still the predominant ground cover. The next day there were two. Warm temps and sunshine took a big whack out of the snow piles, just what the Milbs needed.

These ones were born last August and spent the winter sheltered beneath loose bark or in hollow logs. Their body fluids contain alcohols and glycerols — like antifreeze for your car — which keeps them from freezing when temperatures plummet and food isn’t available.

These winter-hardy butterflies lay their eggs on stinging nettles, the exclusive food of their caterpillars. We have a patch of nettles alongside one corner of our deck — I’ll watch for them there in the coming weeks.

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Milbert’s tortoiseshell   Aglais milberti

A Feat of Nature

The December assignment for my local camera club was feet.

Feet? Really?

A good assignment as it turned out.

Red squirrels
Our woods abound with these arboreal acrobats. They fly up and down tree trunks and back and forth on branches with amazing agility, their sharp-clawed feet keeping them perfectly balanced. Those same feet serve as knife-and-fork equivalents when it comes to eating.

Seagulls

Scaly legs and feet and sturdy claws remind us of this bird’s ancient reptilian relatives.

These feet suit suit them for both land and water but did you know seagulls could also dance?

It goes like this: standing on grass or earth, a hungry seagull lifts one leg at a time, setting it back down again. Explanation: this sets up vibrations in the soil that supposedly trick worms into thinking that it’s raining so they come to the surface. Outcome: seagull gets lunch.

Caterpillars

When it comes to caterpillars we usually talk about their legs rather than their feet.

This larva of the large aspen Tortrix moth appears to have lots of legs but only the first 3 pairs, grouped just behind its head, are true legs. Each of them ends in a short black claw.

The rest of its “legs” are actually prolegs. This caterpillar has 5 pairs — 4 in the middle and one at the rear. Like real legs, prolegs help the caterpillar walk. They also serve as suction cups so the caterpillar can attach itself to leaves and twigs.

Once this caterpillar turns into a moth, the prolegs disappear leaving only the original 3 pairs of true legs.

Crabs

There’s not much left of this Pacific Coast red rock crab but when it was scuttling around it was doing so not on feet as we think of them but rather on the tips of 8 legs. It has 10 legs but the first pair have evolved into large and very effective pincers — they’re also pretty good pinchers if you handle one the wrong way.

What neat feet have you seen lately?

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Red squirrel    Tamiasciurus hudsonicus
Large aspen Tortrix moth   Choristoneura conflictana 
Red rock crab   Cancer productus

 

 

 

Mystery Solved

In an earlier post I pondered what lay within a silky tent strung between segments of chicken wire. A butterfly larva? Or as one reader opined, perhaps a paralyzed caterpillar, soon to be devoured by a spider?

While I wasn’t looking, the caterpillar — which was very much alive and not on anyone’s menu — continued to spin its magic and metamorphosed into a shiny cocoon.

Suspended Animation

Sunlight on silk. Took a closer look. Hey, somebody’s in there!

Caterpillar. Butterfly. In. Waiting.

Watched this rock-a-bye baby for several days but saw no further change. Perhaps I’m just hasty. Time will tell the story.

 

Demise

 

Stop, sit, look is a mantra that serves me well.

I was huddled near the end of a rotting log when I spotted a brightly patterned bug just a few inches away. This was quickly followed by a good-grief-what-the-heck? moment when I realized it was “attached” to a large caterpillar. What followed next was fascinating.

The piercing mouthparts of this immature stink bug had seized hold of one of the caterpillar’s hind “legs” (known as prolegs to bugsters) and it was feeding on the still-living larva.

The caterpillar was strong. It pulled that stink bug several inches across the log face. Despite its best efforts, however, it couldn’t break free.

The stink bug’s grip was stronger. In fact, several times the caterpillar swung loose, dangling in air. The stink bug never lost its hold on the log or the larva.

Although the larva was still alive when I left, the end was inevitable — it was lunch on legs for this young spined soldier bug.

The stink bug’s piercing mouthparts latched on to one of the caterpillar’s hind “legs”.

The caterpillar was strong enough to drag the stink bug across the log face but not strong enough to dislodge the mouthparts.

I spotted the stink bug first and only then realized it was feeding on the caterpillar.

The stink bug will feed well on this caterpillar.

The stink bug’s grip, though slender, was tenacious. Even when the caterpillar swung free in the air, it didn’t dislodge the bug’s grip on either its dinner or the log.

When I first spotted this duo, the caterpillar was clinging to the leaf at the bottom of the log. They travelled quite a distance during this deadly tug-of-war.

The spined soldier bug goes through 5 stages (instars, for the biologically inclined) between egg and adult. Each stage looks quite different than the others. Turns out I found the third instar.

If you’d like to see its life cycle in photos, check out this link at the University of Florida.

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Spined soldier bug  Podisus maculiventris
Unidentified butterfly larva

One for the Books

It was a bizarre sight. If I was a tabloid writer I might have titled this piece “Mosquito Eats Caterpillar”.

Caterpillars appeared on the honeysuckle about the same time as the flower buds.

My early attempts to photograph the critters caught only the back end — the head was buried in the cluster of buds. In fact, to the casual observer they look surprisingly like the buds they dine on.

Caterpillar on twining honeysuckle

When I finally found a caterpillar stretched along a thin branch I took several shots. About the third shot, “holy cow” blew past my lips.

Was that a mosquito?

Indeed it was. It had landed on the caterpillar and as I watched, it sank its sharp little proboscis down into the unsuspecting bud-eater.

The yin and yang of spring.

P.S. How rare is this? If you’re so inclined, you can dip into the research.