Back at basecamp, things were pretty quiet. I was reunited with lots of people I hadn’t seen in a long time which was nice, and as we were getting to the end of the season, we had fewer school students and research assistants, plus some of the staff started to leave. So the atmosphere became a bit more relaxed and fun. Unexpectedly, I got to go back to Guanales for a few days which was really nice. Since I didn’t do anything new this week, I thought I’d tell you a bit more about the light trapping we do each night.
For those of you who don’t know, light trapping is one of the main techniques entomologists use to sample insects. It involves using a powerful UV globe set up against some white sheets, then waiting for the insects to come to you.
Each night, we run a light trap from 7:30 – 9:30 pm. We were looking for three main groups of insects.
Jewel Scarabs are a group of extremely rare, beautiful beetles from the family scarabidae. They’re coveted by collectors, who pay in excess of $1000 for single specimens. Unsurprisingly, this has contributed to their declining populations in a lot of areas. Cusuco has approximately 8 species, including an endemic one, Chysina spectabilis, which is found nowhere else in the world. At the light trap, we record the species and appearance time, then keep them in a little container for the duration of the light trap (to avoid duplicating records) before releasing them.
Longhorn beetles are named, as you might expect, after their extremely long horns (antenna). The ones in Cusuco are very large, and very aggressive. They’ve got big sharp mandibles and aren’t afraid to use them. These guys were not as lucky as the jewel scarabs, as we killed them using ethanol. They’ll be used for DNA analysis back in the UK.
Cusuco has a long-term, comprehensive data set for two families of moths. Sphingidae and Saturnidae. Sphingids have chunky bodies and uneven wings, while saturnids have narrower bodies and look more butterfly-like. We study these two families because they are abundant in the area, relatively easy to identify, easy to attract, and can be used as bio-indicators of ecosystem health. Unfortunately we would have to inject each month with ethanol to kill and preserve it, so they can be formally identified later in the UK (There’s lots of data to show that populations are high enough for this to have no impact).
Here are some photos of other awesome things that come to our light trap.
If you enjoyed this, you should definitely check out Matt’s (one of the other invert team members) flickr page or Instagram. He takes really incredible photos which obviously put my slap dash phone camera photos to shame!