For our first full day of collecting, Arturo Casasola guided us south of Ixtlán, to the community of Lachatao. The winding mountain road brought us to a pine-oak forest that looks a lot like Canada — until you see the bromeliads decorating the trees. It wasn’t quite wet enough to be a cloud forest, but it had some of the elements — not only the bromeliads, but also many other epiphytes (plants growing on other plants) on the branches of the oaks, especially lichens and mosses.
I brought to this collecting expedition a particular concept of where Mexigonus jumping spiders live: mostly on the litter of dry fallen leaves beneath trees. I had formed this idea from previous collecting of other jumping spiders. As I’d collect Habronattus, one of my favourite groups, on such leaf litter, I’d often find a few Mexigonus along the way.
Given this preconception, when we got to the Lachatao forest, I started looking on the leaf litter, and promptly found a little humble brown and tan Mexigonus species quite common there. Good! I decided to try something bold, to look on leaf litter not on the ground, but accumulated in the crooks of branches of the trees. I found a strange cryptically-coloured Mexigonus and was motivated to keep looking above ground. In the end, the team found this cryptic Mexigonus to be common on the epiphyte-covered branches of the oaks — not the habitat of my preconceptions.
We call this species “triste” (sad) for the melancholy expression on their little faces. Here is a male.
It turned out that that wasn’t the only Mexigonus living above ground in the forest. We found a small peppery black species by beating dead branches of trees in shadow. (Beating is a technique we use a lot — we hold a kite-like sheet under a bush or tree and shake or hit it with a stick. For more details see here: https://www.youtube.com/watch?v=oZ1P_3fHtPk)
In the end we found two species of Mexigonus on the ground, as I’d expected, but three species beating bushes and trees (sad face, black pepper, and a third that I’ll describe next post: purple tomato). All 5 of the species are most likely new to science. This is a happy way to dash one’s preconceptions.