Archive | March, 2012

So I got some luna moth eggs…

30 Mar

Luna moth eggs at 80x magnification.

My friend Shawn Hanrahan collected some luna moths last Wednesday, and since they dropped hundreds of eggs he offered batches to anyone interested in rearing some lunas.  I am terrible with caterpillars (-no, really.  The only lep I have successfully reared to adulthood was a pierid that fell to the floor of the container and wound up with useless crumpled wings-) but I decided to give it a go.  So with advice from Shawn (check out his extensive body of pictures and pages on Wikipedia) I have set out on the adventure.  If you don’t hear further you can assumed I failed miserably and am sunk in depression.  On the upside, you can see I am still having tons of fun with the iPhone-dissecting scope photography.

Actias luna hatched egg cases.

Hatched luna moth eggs.

So far, I have successfully hatched luna moth eggs.  Pretty sure that required more work on the caterpillar’s part than my own, but still, points.  Fun fact: luna moth caterpillars eat their way out of their eggs.  I pulled out a cluster of eggshells a day or so after the hatching to take some exciting photos of the empty eggs.  And then I wondered what that green blobby thing in the photo above was.  Had one of the caterpillars failed to emerge properly and died trapped in the egg shell?  (I mentioned my track record with caterpillars, right?)  I detached the grisly relic to get a better look.  (And photos!)

Luna moth caterpillar emerging from egg case (Actias luna).

Hatching luna moth caterpillar.

The grisly relic started wriggling around.  I had actually managed to catch a late-emerging caterpillar in the few minutes of it’s emergence while under a scope with camera iPhone at the ready.

Cool.

Hatching luna moth neonate and egg pile (Actias luna).

Hatching luna moth with eggs.

Obviously I took lots of pictures, and even managed to snag a bit of video.  Moving target don’t make great subjects for scope photography (especially with an iPhone that has to be held at *just* the right distance and angle to pick up the image through the scope) but I got a number I quite like.

Baby luna moth neonate emerging from egg shell (Actias luna).

Hatchling luna moth emerging from egg.

The spiky little caterpillar wriggle and flopped pretty energetically, apparently attempting to drag itself free of the shell, and it was only a matter of minutes before it finished the process and begin busily creeping around the dish.  After a short period of observation I transferred it back to the container to enjoy a leafy banquet with its siblings.

Neonate luna moth caterpillar and egg case (Actias luna).

Newly hatched luna moth and egg shell.

I realize at this point I failed to provide any kind of reference for how exceedlingly tiny these little guys are*, so next is a photo with an insect pin for size reference.  As an aside, I had no idea my insect pins were so glitzy.

(*and yet baby lunas are still bigger than most first instar caterpillars, which in our lab we sometimes call eyelash caterpillars.)

Neonate first instar baby luna moth with egg and pin for size comparison.

Newly hatched luna moth caterpillar with pin head for scale.

Finally, in the spirit of Adrian’s absolutely adorable pictures of “pinned” baby earwigs over at Splendor Awaits, a pinned baby luna moth:

Neonate hatchling luna moth caterpillar on insect pin head.

How many luna moths can dance on the head of a pin?

Next week: baby pictures! Or something.

>>The Luna Moth Saga

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Green Rooms and Gall Wasps

16 Mar
Galls formed by cynipid gall wasps in a leaf.

Eucalyptus leaf galls formed by gall wasps.

This is a green bug for St. Patrick’s day.  (I’m reaching; I know.  Happy Birthday, Eric!)

I’ve talked a bit about gall-forming insects in the past, but I think it bears repeating how extremely cool this adaptation is.  Galls are created by parasites (fungi, bacteria, mites, wasps, aphids, flies, midges, psyllids, etc.)  that use chemicals to co-opt the physiology of their host and cause the plant to grow abnormal structures that make a comfy little home for the parasite in question.  Opening up these particular leaf galls revealed tiny wasp pupae, developing in the safety and luxury of their own private green room.  Chemical warfare at it’s most refined.

Cynipid gall wasp pupae inside a leaf gall (Cynipidae).

Tiny gall wasp pupae inside a leaf gall.

P.S.  Does anyone know if any wasps outside Cynipidae form galls?  That’s the only family I’m familiar with.

Nooooooooo (Attack of the Carpet Beetles)

9 Mar
Bee fly in insect collection with missing eyes due to carpet beetle damage.

Bee fly with eyes eaten out by dermestids.

Here’s a sight no insect collector wants to encounter in the collection boxes.  I was sorting a mixed box of pinned specimens when I found that this fuzzy bee-mimicking fly had met a second untimely fate  (the first being the fate that led him to be pinned in my collection).  As you can see, the large bulbous eyes that occupy most of the bee fly’s head are, um, no longer occupying.  In fact, they’ve been rather neatly eaten away.  Apparently, bee fly eyes are delicious.

Carpet beetle eating collection specimen (Arctiidae, Dermestidae)

Dermestid damage in an insect collection.

With mounting horror I sifted through the collection box and found all the signs: tattered insects, scattered frass, and (the smoking gun) cast off larval skins.  One hairy skin stuck to the wing of a tiger moth whose hollowed out abdomen had apparently made a tasty treat.

Cast off skin of a dermestid larva.

Cast off exoskeleton of a carpet beetle larva (Dermestidae).

Dermestids.  Oh, joy.  Is there any insect that is more unwelcome in an insect collection?  (Actually, my friend Paul had an unpleasant experience with a voracious colony of fire ants, but that’s another story.)  These guys, often called carpet beetles or hide beetles, are dietary specialists on dry, high-protein organic materials.  Everything from dandruff to leather to natural fiber carpeting may become their food source.

Dermestid close up.

Carpet beetle close up (80 times magnification).

This not only makes these beetles a damaging household pest, it makes them both dangerous and very useful to to people who work with dead things.  When they’re not uninvited guests, dermestid beetles are frequently used to “clean” skeletons, removing hide, flesh, and all.  If you’ve every watched the show Bones, you may be familiar with Zack’s colony of “flesh-eating” beetles kept for this purpose.  (Zack: You can’t kill them.  They have names.)

The scaled exoskeleton of a varied carpet beetle (Anthrenus verbasci).

The scaled exoskeleton of a varied carpet beetle (Anthrenus verbasci).

These particular guys were varied carpet beetles, a fairly common indoor pest.  Examining them under a scope reveals that these tiny, nondescript little blobs are quite striking.  The beetles are covered with tiny, multi-colored scales in orange and white and black and their rotund little bodies, with legs retracting into grooves, mak them look something like carnival balloons.  Pretty adorable for something that can leave a trail of carnage and destruction in its wake.

The legs of the dermestid beetle can tuck back into grooves.

The legs of the carpet beetle can tuck back into grooves.

Luckily, the damage was fairly limited (the two specimens pictured here were by far the worst off) so I can consider the whole incident with amusement and interest.  The pictures were fun.  The collection?  Is cycling through the freezer.  Only dead bugs welcome in these boxes.

Pinned dermestid beetle with hand for scale.

Pointed carpet beetle with hand for scale. (Thanks to Loriann Garcia for providing the pointed specimen for the impromptu photo shoot.)

A/N:

Can we talk for a minute about the fact that I took all these pictures with my cell phone?  Forget hoverboards; we are living in the futureRight now.

It would never have occurred to me to point an iPhone down a dissecting scope without Alex Wild’s recent post over at Myrmecos.  Clearly, I had tons of fun with this.  I highly recommend it.

Fire ants vs. Rasberry crazy ants

2 Mar

Here’s an interesting video for you of some interactions between fire ants (the invasive ant species closest to my heart) and a newly invasive ant species beginning to spread across Texas.  Rasberry crazy ants (Nylanderia sp. nr. pubens) were first noticed in the Houston area around 2002.  (For people who don’t keep up with the world of ant taxonomy, most of the genus Paratrechina was moved into Nylanderia in 2010.)

Crazy ants take their name from the way in which they run about very quickly while turning frequently.  The common name is applied to a number of ant genera.  As you can see in the video these ants are fast.  I’ve personally witnessed another invasive “crazy ant” (Paratrechina longicornis) fall into my fire ant colonies and become trapped many times.  Although they can’t climb out again and they are vastly overnumbered they’ll hang out in little groups by the water tube for days, apparently too fast for the fire ants to catch.  Trying to squish them is like playing whack-a-mole.  They also got into the sterile buffer and the coffee.

Thanks to Danny McDonald for providing the Rasberry crazy ants and helping to referee their valiant battle.  Danny is one of the few researchers working in this system right now.