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Mysterious Sign

Posted on February 13, 2011 by Troy Bartlett

15mm | January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

I’m still puzzling over this. Has anyone seen anything like this before? It’s certainly distinctive, but I can’t come up with any theories for what could have done this. It’s on the underside of a live leaf.

Updated: I’m adding a crop from the above photo (from the upper right, rotated a bit).

Crop

Maybe this will help. There’s a tiny tiny critter about one third of the way from the left, near the bottom. I suspect it’s unrelated, but maybe not. I’ve also been thinking that maybe the clumps perpendicular to the main leaf vein might be concealing some sort of hemipteran nymphs. But then what about the oval perimeter? Maybe that serves to discourage predators, like a sort of fence? read more

Posted in Featured Photos | 3 Comments

Reddish Tortoise Beetles

Posted on February 13, 2011 by Troy Bartlett

4mm | January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

There were quite a few of these reddish tortoise beetles feeding on this banana plant.

Banana plant

They feed on the large leaves, scarring them in a distinctive way.

Sign from feeding

Here you can see one munching its way forward, carefully feeding only between the leaf veins.

Machinelike feeding precision

Did you notice the little hitchhiker above? Looks like some sort of parasitic wasp to me. I suspect this is probably a female beetle, and the wasp is just hanging out until she lays eggs, which the wasp will then parasitize. Here’s a closer look.

Parasitic wasp closeup

They’d often fly away from me once I started taking pictures, but it was no trouble to find another one. read more

Posted in Featured Photos | 5 Comments

Hypsiboas rufitelus

Posted on February 12, 2011 by Troy Bartlett

18mm | January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

I photographed quite a few frogs in Costa Rica, but I’m having a hard time identifying them.

My first thought for this attractive little one was that it might be a glass frog of some type (family Centrolenidae), because it appears to be somewhat transparent. Brian Kubicki of the Costa Rican Amphibian Research Center was nice enough to respond to an email and identify it instead as an immature tree frog (family Hylidae), Hypsiboas rufitelus.

Looking around for online photos (here’s one of Brian’s), it looks like they must lose that bold red dorsal coloring as they mature. read more

Posted in Featured Photos | 2 Comments

Army Ant Week Post #3

Posted on February 10, 2011 by Troy Bartlett

January 23, 2003 | Rincón de la Vieja National Park, Guanacaste Province, Costa Rica

OK, I admit it’s not a great photo. What I was trying to show here though was how thoroughly the army ants at the raid front carpet an area, looking for prey. They go in, under and over everything. I usually just step over the raid trails when I encounter them. In this case though, they were very thoroughly blocking the trail I was on. I eventually tip-toed through them, followed by some vigorous foot stomping.

Seeing a raid front really is quite a spectacle though. There are often antbirds flitting around, and it’s amazing to see all the stuff that the ants scare from the leaf litter. I’ve been surprised by just how many hidden critters are suddenly forced into revealing themselves. As potential prey flees the ants, you can’t help but notice how some are immediately set upon by parasitic flies. read more

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Ant, Victimized by Fungus

Posted on February 7, 2011 by Troy Bartlett

Ant, 10mm | Fungal stalk, 5mm | January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

This unfortunate ant fell victim to a fungus, Cordyceps perhaps.

This short sequence from an episode of the Planet Earth series gives a nice introduction to the phenomenon.

Posted in Featured Photos | 6 Comments

Colorful Snout Beetle

Posted on February 6, 2011 by Troy Bartlett

12mm | January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

I really love the colors on this snout  beetle. Check out the detail. The image is not quite as sharp as I’d like, but just look at all those little colorful scales.

Detail

Posted in Featured Photos | 3 Comments

Identification Challenge #8 Reveal

Posted on February 5, 2011 by Troy Bartlett

15mm | January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

I knew the photo above would be difficult to identify, but I was happy that everyone at least figured out it was a spider. As a side note, I hope everyone realizes you can click on the photo to see a larger version.

One commenter, biozcw, ventured that it might be an Argyrodes species. That’s close, because the species I believe I have here, Ariamnes attenuatus, was formerly placed in that genus.

This spider was hiding beneath a large leaf. At only 15mm as shown in the initial photograph, it’s small and virtually disappears when assuming that cryptic position. Here’s a decidedly more spider-like pose. You can just barely see a strand of silk stretching from the spinnerets towards the upper right corner of the image. read more

Posted in Identification Challenges | 1 Comment

Crypsis Challenge #8 Reveal

Posted on February 4, 2011 by Troy Bartlett

January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

Well, this challenge was certainly more difficult than I anticipated. Nonetheless, several people did find the frog in the image above. Below, I’ve outlined it.

Frog Revealed

Now that you know it’s there, I bet you can’t look at the image without it standing out.

Andrea J. went on to suggest it might be a Leptodactylid. I agree. Here’s a close crop from the photo above.

Overhead crop

I picked up this book while in Costa Rica:

[book:0970567804]

According to that book, all Costa Rican leptodactylids lack webbing between their fingers. In the crop above, I don’t see any webbing. There are only three genera in Costa Rica. One genus has only large species, and this one is small. Another has only a single species, easily dismissed because it has extremely warty skin. So by deduction this must be an Eleutherodactylus species. There are 40 highly variable species in that genus that the book calls a “taxonomic nightmare”, so I won’t speculate further on the species. I might even be wrong about the family :). See comments below… I was fooled by the size. Turns out it’s the first genus I dismissed based on size, and it’s just a baby. read more

Posted in Crypsis Challenges | 3 Comments

Identification Challenge #8

Posted on February 3, 2011 by Troy Bartlett

15mm | January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

How specific can you get with an identification for what’s shown above?

Posted in Identification Challenges | 9 Comments

Crypsis Challenge #8

Posted on February 2, 2011 by Troy Bartlett

January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

It’s tough for me to know just how  difficult these crypsis challenges are, since I obviously know what’s in them. I would think this is very easy, but then a coworker commented that others that I thought were easy were in fact hard for him.

Anyway, see how challenging it is for you to spot the critter camouflaged in the photo above. A general identification is fine, since I haven’t yet determined anything more specific.

Posted in Crypsis Challenges | 16 Comments