The other weaver ants

A Camponotus worker stands guard over her leaf nest.

Say “Weaver Ant” to an ant enthusiast and I guarantee you most will imagine the charismatic genus Oecophylla from tropical Africa, Asia, and Australia. Even wikipedia would agree.

But the American tropics also has weaver ants. Several species, in fact.

Wikipedia’s muddled definition aside, weavers are tree-dwelling ants that bind living leaves together with larval silk. These structures remain cool and humid, a perfect refuge from the tropical heat. As weaver ants are defined by behavior, and since the behavior has evolved repeatedly among ants, this is not a taxonomic grouping but a functional one.

During our recent Ecuador excursion we encountered one of the lesser-known weavers. Here’s a nest:

This species is in the genus Camponotus, a group best known for the pesty carpenter ants.

When the nest is disturbed, guards rush out with their gasters facing forward and ready to shoot a stream of formic acid at the intruder. This less-than-endearing habit makes them unpleasant photographic subjects. I had to clean acid off my lenses after taking these shots.

I bring all this up as a suggestion for aspiring myrmecologists. Weaving behavior has evolved enough times to form a replicated natural experiment. Because there are so many separate inventions of weaving (at least 5 or 6), statistical techniques can be used to infer the characteristics that predispose lineages to evolving a weaving lifestyle. If you are looking for a good ant evolution project, say, the sort of work one might do for a Ph.D. dissertation, this topic is ripe for the picking.

photo details:
(top, bottom) Canon 100mm f/2.8 macro lens on a Canon EOS 7D
ISO 200, f/13-14, 1/200 sec exposure, indirect strobe
(middle)Tamron 11-18mm wide-angle zoom on a Canon EOS 7D
ISO 200, f/9, 1/250 sec, hand-held fill flash.

14 thoughts on “The other weaver ants”

    1. That’s a good question, Andrew, with a complicated answer. Not all advisors are good for all people- some of it is academic, but other parts just come down to personality and can be difficult to predict.

      You could start by look at the labs that produce the studies that most interest you. If you like leafcutter ant work, for example, you might look at labs at the Smithsonian, the University of Texas, or the University of Wisconsin. If you were more into the theoretical aspects of evolution, there are dozens of potential labs producing top-notch work.

      With a list of potential advisors, you could start inquiring at each as to whether the lab is taking on new students, has funding to support you, and any admissions requirements.

      1. I don’t think Ted Shultz, Ulrich Mueller, and Cameron Currie are strangers after reading your blog! Actually Alex, you’ve inspired me to pursue a Ph.D. in studying ants, as opposed to one in biomed(which I was more inclined to do like 2 years ago!).

        I do have a list of advisors, but I meant to ask who would be good ones for studying weaver ants?

  1. Oh Man, now you tell me! This is similar to my MS project on burrow and door construction of some of the mygalomorph spiders…

  2. I wonder if this is the right size for undergrad research? When I go to college I’m really looking for an opportunity to do undergrad research, and so far I’m looking at UChicago, Emory, and Harvard (ha, like I’ll get in there) as good places for entomological research. Any pointers on research for undergrads?

    1. Check out….UC Davis, Univ of Illinois Urbana-Champaign, NCSU, Boston University, Penn State University Entomology(David Hughes does the ophiocordycep parasites on camponotus ants), Arizona State U, Cornell…I’m prolly missing a lot, but off the top of my head, these schools do really cool research!

      I had trouble as undergrad to get into a lab with a prof…so you have to read papers, kiss a lot of ass, have good grades, and be enthusiastic…and it seemed like the more you pester the profs, the more likely you’d get into their lab.

      1. You raise an important point, Andrew. The big R1 institutions are not aimed at undergrads, and it takes an especially ambitious person to get solid research training at a University geared towards graduate students.

    2. Too much for an undergrad project. The trouble is we know very little about weaver ants other than Oecophylla, so someone needs to spend the time and the money to live a few months up in tree canopies in various places just working out their basic natural history. That’s definitely PhD fodder, rather than something you can do between coursework.

      If the data already existed, that’d be another matter. You’d merely need to generate a phylogenetic tree, map the characters to it, and perform the requisite statistics.

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