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Alpaida species?

Posted on February 21, 2011 by Troy Bartlett

5mm | January 17, 2011 | Cahuita National Park, Limon Province, Costa Rica

One of my books (below) has a picture of a very similar looking spider identified as a spiny flag spider, Alpaida cornuta, also from Costa Rica. I wasn’t able to find anything online though using either the common name or the scientific name. The World Spider Catalog doesn’t seem to recognize that name at all, but I saw two species there from Costa Rica, A. bicornuta and A. championi. Perhaps this is one of those.

Here’s a similar looking unidentified Alpaida from Ecuador, so I think the genus is probably correct. read more

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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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Gonyleptid Harvestman

Posted on November 22, 2010 by Troy Bartlett

January 28, 2010 | Caraça Natural Park, Minas Gerais, Brazil

This image of a harvestman in the family Gonyleptidae is one of my favorites from my trip to Caraça Natural Park.

As a kid, I cherished my Golden Guide to Spiders and Their Kin. Ever since I saw an illustration therein of a wild looking Gonyleptid, I’ve wanted to find one. I got excited early in the trip when I found a shed skin. On the last night, I was out with my headlamp and I encountered not just one but two!

They were both difficult to photograph. Although slow moving, they just wouldn’t stand still. I had to keep herding them back onto the trail. Eventually, this one stopped in an area that made for a relatively uncluttered background. read more

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Silver Argiope with Wasp Prey

Posted on November 20, 2010 by Troy Bartlett

January 27, 2010 | Caraça Natural Park, Minas Gerais, Brazil

This spider was on an exposed ridge overlooking the sanctuary. She appears to have caught a nice sized wasp.

This species often creates an X-shaped design (stabilimentum) in their web, and you can just see a hint of one extending to the lower right.

The common name Silver Argiope is consistent with the scientific name (argentata = silvery). Even the common name in Portuguese, Aranha-de-prata, translates as Silver Spider. It is indeed silvery.

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Orb Weaver

Posted on November 6, 2010 by Troy Bartlett

January 27, 2010 | Caraça Natural Park, Minas Gerais, Brazil

This orb weaver was safely tucked away inside a leafy retreat.

The general shape puts me in mind of Acanthepeira species here in the US. There is at least one species, A. labidura, in Brazil. I couldn’t find any information on it though.

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Pelecinid Wasp

Posted on November 1, 2010 by Troy Bartlett

January 28, 2010 | Caraça Natural Park, Minas Gerais, Brazil

Wasps in the family Pelecinidae are distinctive and easily recognized by that long thin abdomen. I’ve see them closer to home as well, but I can’t recall if I’ve ever gotten a decent photo. I do remember chasing after quite a few in vain or watching as one teased me from someplace just out of reach. I got lucky with this one.

What I thought was a red marking turns out to be a small mite.

There’s only one genus, Pelecinus, for this family. There appears to be at least two described species in the tropics. read more

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Tick Anatomy Lesson

Posted on October 25, 2010 by Troy Bartlett

January 28, 2010 | Caraça Natural Park, Minas Gerais, Brazil

This tick is one of the largest I’ve ever encountered. I’m happy to say it was the only one I saw.

Ticks often wave around their forelegs while perched like this, hoping to grab on to some passing potential host.

When viewed from the side, there’s an interesting bit of anatomy exposed.

Side view (do you see the smaller mite bringing up the rear?)

I wondered about the purpose of that large hole on the tick’s side so I did some research. It’s called the spiracular plate, and it’s basically a tube into the tick’s breathing system. Calling it breathing might be a stretch though. It’s really more of a passive gas exchange. The shape of spiracular plates are also used by taxonomists as a way of distinguishing various types of ticks. read more

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Dueling Salticids

Posted on August 17, 2010 by Troy Bartlett

Standoff | January 26, 2010 | Caraça Natural Park, Minas Gerais, Brazil

I first spotted just one of these male jumping spiders. As I prepared to take some photos, it became aware of another male nearby. They approached one another and were obviously sizing each other up in preparation for a fight. Neither backed down, and so the fight was on.

Fight!

I like how they raise their pedipalps like boxing gloves. Or maybe that’s just to keep them away from the others fangs? Which would you bet wins this bout?

Knockout!

According to the timestamps on my images, they fought for around seven minutes. It looked like the object was simply to dislodge the opponent and send them tumbling away. You can see how they are using their long front legs to try and grab the other’s hind legs and pull them out from beneath each other. This is the knockout shot, as the one on the left has succeeded in grabbing the right one’s hind leg and right after pushed it off the leaf. read more

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Acrobatic Harvestman

Posted on July 26, 2010 by Troy Bartlett

This harvestman was climbing amongst some leaves, no doubt searching for prey.

January 25, 2010 | Caraça Natural Park, Minas Gerais, Brazil

Wandering in search of prey

Here’s some other interesting shots of this individual. If you look carefully, you can see some white mites.

Mouthparts closeup

Abdomen closeup

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Trechaleid Spider with Young

Posted on July 19, 2010 by Troy Bartlett

The first thing I photographed after arriving in Caraça Natural Park was this hunting spider, found wandering in an unpaved parking area.

Trechaleid Spider with Young | January 25, 2010 | Caraça Natural Park, Minas Gerais, Brazil

Up until I started preparing to write this post, I figured this was a wolf spider. After reading to learn more about the parenting behavior shown here, I’m now convinced it is instead a species in the family Trechaleidae. What first tipped me off was a similar photograph in this little book:

[book:0060849746]

Several identifying characteristics are mentioned for the particular species pictured. After some online searching, most appear to be shared by other species of the family. read more

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