A(i)nt and gast(e)ropost

While at the Los Tuxtlas field station I had the opportunity to be attacked by numerous arthropods, including trombiculid mites (chiggers), numerous species of ants, and an urticating caterpillar. Don’t laugh about the caterpillar!  They can kill you. But the one that got me only left a caterpillar-shaped welt on my shoulder. I’ll describe two ant attacks of note. One involved an invasion of sleeping quarters by male and female ants after a hot day and heavy rainstorm induced a flight of reproductives. The bedroom walls and ceiling were covered in winged ants, which proceeded to fall down on the bed at night. One added both injury and insult by biting my bottom.

winged ant queen like the one that bit me in bed Los Tuxtlas 18 July 2014 sml

One of many reproductive female ants that swarmed the bedroom in Los Tuxtlas. Unfortunately, I don’t know the genus.

The next morning I took some photos of the remaining reproductives, which revealed that the males have grotesquely enlarged and protuberant ocelli.  A cursory Googling revealed that ocelli tend to be larger in reproductives of night-flying ant species, but I couldn’t find a good explanation for the sexual difference. This paper suggests that males of Myrmecia (a genus different from the that of the ants that fell on me) may have to engage in more intense visual tracking to find the females for mating.

ocelli of female vs male reproductive ants Los Tuxtlas 18 July 2014 sml

Heads of female (left) and male (right) reproductive ants showing the difference between the sexes in relative size and sphericality of the three ocelli.

The second ant attack occurred when I was peaceably watching a lecture on salticid taxonomy in the lab. Suddenly I felt a burning pain on my throat. Remnants of the crushed body of the perpetrator revealed that it was a Pseudomyrmex, probably P. salvini.  This ant was many times larger than the other species of Pseudomyrmex that had attacked my hand near Chamela, and it produced a goiter-like swelling commensurate with its size. I don’t know what induced it to stab me in the neck – sheer viciousness, perhaps. But on the bright side, the nasty nature of the Pseudomyrmex is probably why a particularly striking species of jumping spider mimics it. The a(i)nt pictured below with its model is a species of Synemosyna. They were common on the station walls and foliage.

Pseudomyrmex most likely salvini and Synemosyna mimic Los Tuxtlas 14 July 2014

Pseudomyrmex ant on left and a mimicking Synemosyna salticid on the right.

 So there is the gasteropost – on to the gastropost.  In Morelia we had much enjoyable food and drink, including a surprisingly good Mexican IPA, but there was also some awful stuff. One meal resulted in a three day trial of having my Edmontonian gut flora violently replaced with a Morelian community. After that had settled down, I decided I was digestively robust enough to sample a mysterious drink called a ‘Michelada’, which was advertised everywhere, but I had no idea what it might be. When the beverage arrived, this is what it turned out to be:

Michelada trimmed

Creating the Michelada – beer plus Clamato juice. Urgh. (photo by Wayne Maddison)

I managed to drink about a fifth of the concoction before the guts said ‘no’! Tastebuds concurred. But as odd as this beer+Clamato sounds, there is an equivalent in Alberta: the Red Eye. Why someone decided to replace the vodka in a Caesar with beer is unclear to me.

A more pleasant food experience took place in Mexico City after I had given my talk at UNAM. My host, Dr. Tila Pérez, took me and some other arachnologists to a traditional restaurant for lunch. There in addition to delicious moles (poblano, negro, verde and rojo), we sampled some unusual appetizers. My favourite was escamoles – fried ant juveniles (maybe a mixture of larvae and pupae) served with guacamole and eaten with tortillas. They tasted like buttery fried things, and I enjoyed them maliciously.

escamoles - fried ant pupae raised on agave roots Mexico City 28 July 2014

Fried baby ants – delicious revenge! (photo by Grislda Montiel)

Arachnids at Los Tuxtlas


students collecting Los Tuxtlas 14 July 2014 B sml

Students collecting around the field station.

I spent an enjoyable week of this July at the UNAM Los Tuxtlas field station in Vera Cruz, Mexico, sitting in on a field course and taking a macrophotography holiday. The course was on the taxonomy and biology of Salticidae jumping spiders, and was run by Wayne Maddison from the University of British Columbia (Canada) and Gustavo Ruiz from the Universidade Federal do Pará (Brazil).


Seventeen undergraduate and graduate students from Mexico, Central America, and South America were eager vessels for the instructors’ salticidological wisdom.

classroom Los Tuxtlas 16 July 2014

Classroom at Los Tuxtlas.

Jumping spiders were abundant and conspicuous at Los Tuxtlas.  Quite a contrast from the situation in Alberta, where hunting salticids requires a vast amount of patience and belief in divine intervention. Here is a small selection of the beautiful jumping spiders we saw.

big male Freya regia on leaf Los Tuxtlas 14 July 2014 sml

Despite being named for the Norse goddess of love, this Freya is all man.

Corythalia on wall Los Tuxtlas 16 July 2014 sml

One of about a dozen species of Corythalia from Los Tuxtlas.

Lyssomanes male Los Tuxtlas 17 July 2014 sml

Male Lyssomanes maddisoni court via semaphore.

There was a great diversity of other families of spiders at Los Tuxtlas. Large wandering spiders of the genus Cupiennius (Ctenidae) were everywhere. Less common, but a great treat for me as I hadn’t seen them since I lived in Australia more than a decade ago, were two-tailed spiders (Hersiliidae). Neither is as flashy as most salticids, but they have a subtle beauty of their own.

ctenid Cupiennius on wall UNAM Los Tuxtlas 14 July 2014 trimmed sml

Cupiennius on retaining wall.

two-tailed spider Hersiliidae Los Tuxtlas 17 July 2014 sml

Two-tailed spider (Hersiliidae)

In addition to Araneae, I saw many other orders/superorders of arachnids at the field station including Acariformes, Opiliones, Palpigradi, Parasitiformes, Pseudoscorpiones, Ricinuleida, Schizomida and Scorpiones. The only terrestrial ones I didn’t see were Solfugida, Amblypygi and Uropygi, though the latter two were no doubt there. I was particularly excited to photograph live ricinuleids. At one point they were thought to be the sister group to mites because they shared with the Acari a 6-legged larval stage, among other things. Molecules say otherwise, though, both with regard to the relationship between mites and ricinuleids and the monophyly of mites themselves. Unfortunately, the post-larval ricinuleid got tangled up in residual spider webbing from the vial it was held in, and was too hobbled to walk naturally.

trombidioid Los Tuxtlas 15 July 2014passalid venter with mites Los Tuxtlas 15 July 2014 sml

gonyleptid sl opilionid Los Tuxtlas 14 July 2014scorpion prob Chactidae 16 July 2014 sml

ricinuleid larva and HPs pinkie finger Los Tuxtlas 16 July 2014 smlricinuleid adult unfortunately webbed up Los Tuxtlas 16 July 2014 A

Non-spider arachnids, starting at top left: acariform mite, parasitiform and possibly also acariform mites on the venter of a passalid beetle, opilionid, scorpion, 6-legged larval ricinuleid and my pinkie finger, post-larval ricinuleid.

There and back again

Two days ago I got back from another trip to Mexico!  The first destination was Los Tuxtlas, one of the two large UNAM field stations (Chamela being the second of the pair). This station is located in rainforest in Vera Cruz on the Atlantic side of the country. After a week there it was off to the old city of Morelia in Michoacan to attend an arachnological conference. Morelia’s history and amazing architecture definitely justify its being a World Heritage Site. The trip ended with my giving a talk at UNAM in Mexico City. But despite the many wonderful opportunities for photography of landscape, buildings and people, most of my tourist shots were taken with a cell phone from the vans and buses in which we traveled. A compilation of such images arranged in rough temporal order is below. Posts on arthropods will follow.

collage of on-the-road travel pix Mexico July 2014 reduced