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Here. Los Tuxtlas Biological Station in Veracruz, Mexico. Closest "city" of note, Catemaco. The station is run by UNAM (Mexico's largest and arguably best university), and I'm here with researchers from UCLA studying damselfly behavior and mating.
I spend 9-5 kneedeep in a creek, catching and marking damselflies (Hetaerina titia and Hetaerina occisa). How do you mark an insect? With some kind of fancy high tech marking techniques? Nope. With paint pens. Each damselfly gets a four digit color code, which then gets painted onto their abdomen. We record it's sex, species, and location and then take a picture of its wings (often the hardest part of the process) and let it go where we found it.
Why? Because there are two species of damselflies in this area with some interesting behavior. The two species are very closely related, close enough that even they will confuse each other. This could be a major problem when it comes time to mate, as wooing the wrong female could cost you a lot of time and energy. So it appears that one of the species, titia (above) starts developing black wings during the mating season, and only during the mating season. This only happens when both titia and occisa are found in the same stream. When the species are apart, they both keep their clear wings.
What we're interested in finding out is How do titia know when to develop those black wings? and Is it really used for identification of their species? To test the first question we set up one section of the stream where we're darkening the males' wings earlier than usual, to see if newly emerged damselfly males take their cue from seeing older males with darker wings. To test the second question, we conduct tethering tests. We (and by we I mean the infinitely dextrous J.P.) attach a female damselfly to the end of a fishing line with some duct tape. Then we "fly" her past a territorial male to see if he's interested. To make it interesting we darken some of the females' wings, to see if a) he's still interested in a titia female whose wings are darkened earlier than usual, and b) if he can be duped into believing an occysa female is a titia, if her wings are darkened. We use a similar process to see if territorial males will defend their territory against males of the other species, with and without darkened wings.
Stay tuned for results. For awhile. Because we won't know anything until, like, this Fall when J.P. analyzes the data.
