I work on a groups of bugs that aren't very common or well known. Not only are they cryptically colored but you can only find them in the tropics where they're not particularly abundant. This combination means they happen to be pretty infrequently collected and observed even less often. Even if you did spot one, you’d probably have no idea that these cryptic bugs can possess such interesting biology and behavior
The insects I’m talking about are assassin bugs in the subfamily Salyavatinae. At least one species, Salyavata mcmahanae, has been comparatively well studied. Check out this amazing documentary clip below.
The genus Salyavata is the only salyavatine that you can find in the New World, but there’s a whole group of other genera in Africa and Asia; check out the diversity of the group in the pictures below. You can see that some have strange enlarged fore legs often covered with unique hairs, and that sometimes the females possess larger forelegs than males by quite a bit. Intriguing right? Unfortunately, we have no idea why (in an evolutionary sense) and no one has ever observed these bugs “use” their uniquely modified legs. Like S. mcmahanae, a meager handful of species in Africa and Asia have literature reports recording them as being observed near or feeding on termites, but unlike S. mcmahanae, none has ever had any special study devoted to it. Another subfamily, Sphaeridopinae (also pictured), is thought to be a close relative of this family and might specialize on termites, as one species has been caught near a termite nest and fed on those termites in captivity (P. Wygodzinsky pers. comm. in McMahan ).
After spending some time thinking about this problem, I decided to try and find a solution, at least partly and at least for my group, where all the members were suspected to be specialist termite predators. I designed three pairs of primers, or small chunks of DNA, that matched the sequence of termite genes but not the corresponding gene in assassin bugs. Then tried to amplify small chunks of termite DNA out of the guts of ~50 specimens of Salyavatinae from around the world including the E. tarandus specimen I collected in Cameroon. This had the potential to definitively prove that that specimen had been feeding on termites!
The extraoral digestion and liquid diet of assassin bugs probably hastens the degradation of DNA in gut contents (as has been noted in other related sucking predators) so I wasn’t as successful as theoretically possible, but overall, I found out that quite a few specimens seemed to have been recently feeding on termites. Some of the genes I amplified were even variable enough to be able to be matched down to a species of termite, as long as someone had catalogued that DNA sequence before on GenBank. I also found that my success rate for adult females was higher than for adult males in line with the theory that females may be consuming more as adults for egg production. I also used some other primers for two hyperdiverse insect orders to check to see whether the bugs might be generalists.
I gathered even more evidence of termite specialization by these bugs using another online resource: flickr.com. Everyday hundreds of potentially scientifically valuable images are uploaded to flickr and other online resources and this represents a huge untapped resource for scientific studies. There are a growing number of photographers who are based right in the tropics and have the ability to document natural history relatively inexpensively. Check out some of the fantastic photographs below.
Nicky Bay (http://sgmacro.blogspot.com/), Paul Bertner (https://pbertner.wordpress.com/), Steen Dupont, Bruce Gill, Stéphane de Greef (http://www.stephanedegreef.com/), Hock Ping [Kurt] Guek (orionmystery.blogspot.com), John Hash (https://twitter.com/phoridfly), James Koh (https://www.flickr.com/photos/jameskoh/), Gernot Kunz (http://gernot.kunzweb.net/), Steve Marshall, Aaron Pomerantz (https://twitter.com/aaronpomerantz) and Melvyn Yeo (http://melvyn-yeo. blogspot.com/).
My name is Eric Gordon and I'm a graduate student researcher at the University of California, Riverside who works with Christiane Weirauch and systematics of assassin bugs and the bacterial symbionts of Heteroptera.
Gordon, E.R.L., Weirauch C. 2016 Efficient capture of natural history data reveals prey conservatism of cryptic termite predators. Mol. Phylogenet. Evol. 94: 65-73.
McMahan, E.A., 1982. Bait-and-capture strategy of a termite-eating assassin bug.
Insect. Soc. 29, 346–351.