Spiders

Face of the Brown Recluse

Loxosceles reclusa, the brown recluse
Loxosceles reclusa, the brown recluse

Among the more interesting animals to appear at the BugShot photography workshop was a Loxosceles reclusa caught wandering about the basement of the assembly building. I had never seen one before.

Most of us are taught to recognize the famously venomous recluse by a violin-shaped pattern on the spider’s back. But other species, including some common wolf spiders, sport similar markings, so it is better to make use of eye arrangement to confirm the identification. The recluse’s eyes are grouped, unusually, into three clusters: a central pair and two lateral pairs, clearly visible in the photograph above. (more…)

Not the ant I thought it was…

High on my to-do list in Ecuador was Pachycondyla villosa. This is a large, wasp-like predatory ant coated with fine golden hairs. After some looking, one morning I finally spotted a worker foraging in the understory at Jatun Sacha. I came in for a closer look:

Sphecotypus niger

Approaching within ten inches I realized something wasn’t right. Even though the animal moved just like P. villosa, and even though the sun glinted off its elongate body at just the right hue, the antennae were slightly…weird. (more…)

The Ant that Wasn’t (Aphantochilus rogersi)

Aphantochilus rogersi (left) with prey

The most astounding arthropod I found in Ecuador last month wasn’t an ant, believe it or not, although it looks just like one from a few feet away.

Aphantochilus is a crab spider slightly over a centimeter long.  The species isn’t exactly uncommon in the Neotropics- in fact, Aphantochilus has appeared previously on Myrmecos. Rather, it is spectacular for its color, size, shape, texture, and movement. Aphantochilus is a convincing stand-in for Cephalotes atratus, the giant turtle ant, and every time I see one lurking about the margins of a turtle ant trail I do a double take and gleefully pass the next half hour watching it work.

Last month’s encounter was the first time I had a camera handy. Thus, some photographs to share with you folks.

A quiet moment

Although it may seem that the spider uses its impressive camouflage to fool its prey, I am not convinced.

The vision of most ants is rather rudimentary, enough that I think it unlikely such remarkable visual mimicry would yield enough of a payoff to be worthwhile. Ants perceive their environment predominately in a chemical medium. Instead, I suspect the spider intends to fool other visual predators- birds, maybe- that would normally pass up acidic chitinous ants but would happily take a spider. For more detailed explorations of the topic, see here and here.

Which is the spider, and which is the ant?

photo details
Canon EF 100mm f/2.8 macro lens & 12mm extension tube on a Canon EOS 7D
ISO 200, f/16, 1/250 sec. Indirect strobe bounced off white paper