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

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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

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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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Army Ant Week Post #2

Posted on February 9, 2011 by Troy Bartlett

July 20, 2006 | Ilhabela, Sao Paulo State, Brazil

These two photos are from my first trip to Brazil. I spent a week on the island of Ilhabela, a few hours drive from Sao Paulo.

I probably wouldn’t even have noticed these ants if not for the calling of antbirds. The birds were making quite a fuss so I moved in to investigate. That’s when I started to hear a light rustling noise and then noticed the ants carpeting the leaf litter. The rustling is not just the ants, but all of their potential prey trying to escape.

Below, they’ve managed to overwhelm a spider, er, well, actually just a shed spider skin. Honestly, I always believed this was a captured spider until reviewing it yesterday when I noticed something was off. read more

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Army Ant Week Post #1

Posted on February 8, 2011 by Troy Bartlett

In honor of Army Ant Week, I’m going to take a short break from my recent Costa Rica photos to post a few army ant photos.

June 7, 2004 | Barro Colorado Island, Panama

The only time I’ve ever seen an army ant bivouac was on a trip to Panama. I don’t recall if the photo above was of part of the bivouac or just an ant bridge somewhere along a foraging trail. My field notes were unfortunately lost in a house fire several years ago.

This could be Eciton hamatum, based on Alex Wild’s post today on that species. They are definitely orange, and I don’t recall being bitten or stung. If they are some other species, I’m sure I’ll be set straight in short order. 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.

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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

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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

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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

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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