Identification Challenge #14 Reveal: Arched Hooktip

April 7th, 2012 - 11:00 AM | Filed under Identification Challenges | No comments

27mm wide | March 24, 2012 | Twelvestones, Roswell, GA, USA

No one commented on the latest identification challenge. Despite showing just the tip of the forewing, the image provided showed the distinctive feature of a subfamily of moths commonly called hooktip moths. If you got that far, it’s a pretty simple process of elimination since there are only a handful of North American species, each one easily distinguished from the other. This species is the Arched Hooktip, Drepana arcuata.

This individual appears to be a male, based on the widely bipectinate antennae.

Male, based on antennae

As I mentioned in the original post, this moth was reared from a caterpillar I encountered late last year. They feed on alders and birches. I found this one on alder, within a leaf it had folder over using its own silk.

Sheltered within a folded alder leaf | 20mm long | October 29, 2011 | Buford, GA, USA

I raked my fingertip through the silk, in order to get a clearer view.

Clearer view

These caterpillars have enlarged warts, shown here.

Closeup of enlarged warts

It’s actually quite a handsome caterpillar. Note the bands on the head capsule, which no doubt inspired its common name, Masked Birch Caterpillar.

Frontal view

One other interesting thing about these caterpillars is that they scrape or beat parts of their anatomy against the leaf in order to advertise their presence to neighboring individuals. In this way they can space themselves out and avoid unnecessary competition.

Reference:

Caterpillars of Eastern North America
by David L. Wagner

Identification Challenge #14

March 24th, 2012 - 3:57 PM | Filed under Identification Challenges | 1 Comment

March 24, 2012 | Twelvestones, Roswell, GA, USA

Today I found my first moth in the overwintering container I keep outside. Can you identify it from this wing fragment? I’ll keep the comments hidden for awhile, but this should be an easy one.

Identification Challenge #13 Reveal: Spotted Apatelodes Proleg

October 16th, 2011 - 5:15 PM | Filed under Identification Challenges | 4 Comments

Spotted Apatelodes Caterpillar | October 2, 2011 | Twelvestones, Roswell, GA, USA

Did you guess that the caterpillar above was the critter featured in Identification Challenge #13? Both commenters for this challenge were on the right track, guessing that it was a caterpillar. Here’s the photo again from the challenge.

Proleg closeup

Here’s an even closer look at the proleg so I can point out a few interesting things.

Proleg showing crochets in two different sizes

All those little claws on the proleg are called crochets. This particular species, Apatelodes torrefacta, is one of just a handful of species in my area that belong to the family Bobycidae. The most famous member of that family is the domesticated silkworm moth. One feature of caterpillars in this family is that they have crochets of two different lengths, as shown above.

An identifying characteristic of Apatelodes torrefacta is its vivid red legs. They contrast with the overall color, which varies from white to yellow. Here’s some more interesting compositions of those distinctive feet from the individual featured in this challenge.

Pair of prolegs

In the next shot, note how the middle pair of prolegs appear to be missing crochets. In fact, this shot was taken as the caterpillar was moving forward. The crochets are hidden behind the prolegs, not retracted but bent backwards out of view. The front top proleg is just starting to lift.

Prolegs, showing crochet action

Here’s all the midabdominal prolegs.

All the midabominal prolegs (anal claspers not shown)

Compare the prolegs above with the true legs shown below. It’s easy to see how the prolegs would have significantly more grasping power with all those extra claws.

Head and legs

If you’re familiar with this species, you might have noticed that it’s missing one of its front lashes (the longer sets of hairs). This individual was readily losing hairs as I photographed it. Based on size and time of year, this individual was almost certainly prepupal. At that stage, they easily shed their hairs and are apt to lose their lashes as well. If you look carefully, you can just see the red prolegs grasping the twig.

Side view showing missing lash

Here’s a few notes on the photos. The two images showing the full caterpillar were taken in front of some attractive foliage in my yard. The rest were taken through glass, allowing me to capture the underside. I wasn’t sure the caterpillar would be able to grip the glass if I flipped it over. To my surprise, it held fast once I did. It immediately started laying down silk on the glass though. I thought at first it might be spinning a cocoon, but in fact it was just laying down a silk track to walk on. At the end of the photo session, there was a small trail of silk on the glass where it had slowly made its way forward. You can see some of those silk strands on the glass in the photo above showing all the midabdominal prolegs as well as the one after that showing the true legs.

Here’s a a smaller white caterpillar I found in my yard a few years ago. I photographed this one against sun-dappled pine straw. This one has all its lashes.

September 18, 2008 | Twelvestones, Roswell, GA, USA

White individual with all three lashes

The red prolegs must develop in later instars, because this one still has white prolegs.

White prolegs in this earlier instar

I’ve certainly seen adults of this species, but I couldn’t find an image of one among my photos. If you’re curious, there’s plenty on BugGuide.

Reference:

Caterpillars of Eastern North America
by David L. Wagner

Identification Challenge #13

October 9th, 2011 - 5:33 PM | Filed under Identification Challenges | 4 Comments

October 2, 2011 | Twelvestones, Roswell, GA, USA

Despite appearances, I promise this is not an underwater shot of some strange anemone. I brought this critter home from a recent walk in the park.

This could be a difficult challenge. Nonetheless, I bet someone will be able to identify the species shown here. To give you some sense of scale, I had my 65mm macro lens maxed out at 5x for this shot.

Identification Challenge #12 Reveal: Emesinae

June 21st, 2011 - 6:31 PM | Filed under Identification Challenges | No comments

30mm (body) | January 20, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

Only one reader commented on the latest identification challenge. Bryan Reynolds found it easy to identify this as a thread-legged bug in the subfamily Emesinae (family Reduviidae). Be sure to check out Bryan’s new non-profit, The Butterflies of the World Foundation.

This thread-legged bug was spotted in some leaf litter, finishing off some sort of nondescript prey.

Identification Challenge #12

June 17th, 2011 - 8:57 PM | Filed under Identification Challenges | 2 Comments

30mm (body) | January 20, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

Can you identify this critter as far as subfamily?

Identification Challenge #11 Reveal: Derbidae

May 30th, 2011 - 8:24 PM | Filed under Identification Challenges | No comments

15mm (wingspan) | January 20, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

Both commenters on the last identification challenge correctly identified the critter above as a planthopper in the family Derbidae.

At a glance, you might mistake these hemipterans for lepidopterans. The first thing you might notice as being a bit off are those antennae. If you look closely enough, you’ll see the typical hemipteran rostrum.

Here’s another one, with what appears to be an abdominal injury.

Another derbid

Reference:

500 Insects:
A Visual Reference

by Stephen A. Marshall

Identification Challenge #11

May 27th, 2011 - 6:13 PM | Filed under Identification Challenges | 4 Comments

15mm wingspan | January 20, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

Can you identify what family this critter belongs to? Comments will be held in moderation until the answer is revealed in a few days.

Identification Challenge #10 Reveal: Phiale guttata

May 7th, 2011 - 8:08 PM | Filed under Identification Challenges | 2 Comments

15mm | January 19, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

Only Ted C. MacRae ventured a guess for this most recent identification challenge. He was exactly right, though a bit confused by his source which indicated this species might not occur in Costa Rica. This is indeed Phiale guttata.

The World Spider Catalog lists the distribution for this wide ranging species as Costa Rica to Paraguay. The Global Species Database of Salticidae site lists all the species for Costa Rica, and allowed me to eliminate the possibility of similar spiders in the same genus. There are also some good photos and illustrations there.

This specimen was impressively large, perhaps the largest salticid I’ve ever encountered. A snippet from “A mimicry complex between mutillid wasps (Hymenoptera: Mutillidae) and spiders (Araneae)”  states that this is the largest Salticid from the study area. I can’t access the article, but the title suggests this species might mimic velvet ants (Mutillidae). The snippet also mentions two color morphs, yellow and black as here, as well as red and black. It must be quite variable, because there’s a photo here of a white and black morph as well.

This female’s abdomen appears even larger than normal. I’d guess she’s gravid.

She was quite photogenic, so here’s some more photographs.

Dorsolateral facing right

Lateral facing left

Face on

Stealth attack

Ready to pounce

Identification Challenge #10

May 5th, 2011 - 8:47 PM | Filed under Identification Challenges | 2 Comments

15mm | January 19, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

I was able to identify this to species and determine the sex. Can you? Luckily there’s lots of online resources for this family. Comments will be held in moderation and I plan to reveal the answer sometime this weekend.