It was a successful year for science and wildlife.
Once again, I joined Dr. Drew Talley and Dra. Dr Natalia Rodriguez Revelo for a summer survey of the islands in Bahia de los Angeles, Baja California.
The work on the islands went well, and we got data regarding beetle populations from twelve islands. It is also a highlight of my year to spend the time with my best friend and our wonderful colleague.
Although work on the islands can be challenging, we are usually done by late morning, and there is time for other activities. This year, I thought it would be interesting to test the thermal resilience of some of the beetle species. The specific idea is that beetles that produce defensive chemicals (like Eleodes does) would be more sensitive to extreme conditions such as high temperature when compared with undefended beetles (such as Philolithus in Santa Fe or Cryptoglossa in Bahia). This has been assumed to be the case, but has not been tested rigorously.
My idea was simple: collect beetles from two species, one defended and one undefended, and test their survival at temperatures ranging from benign to lethal. My prediction would be that the undefended beetles would survive at higher temperatures than those that invest energy and water in defensive scent glands.
We decided it was better to collect the experimental beetles on the mainland. The project was added to the permit application along with the other, ongoing projects. However, the permit only allowed us to survey the beetles on the mainland, not collect or test them. Nonetheless, sampling would allow us to determine where it would be best to find enough beetles for experiments in the future.
For our first sampling location, we set traps at the local dump. We reasoned that we could avoid protected areas and private property by sampling at the dump.
We set nine pitfall traps, baited with oatmeal along an arroyo. After checking back every afternoon for three days, we had caught six Cryptoglossa muricata. It was good to find beetles that would be appropriate for experiments, but we needed at least two species, and about 40 of each. We thought it best to look elsewhere.
We thought that the Glendale Community College field station might be a better location, so we asked Jared Ocampo, an old friend and the station manager, for permission to set traps around the station. He agreed, and even helped us set the traps.
We set a total of 24 traps in three sets of eight. One group was set in an arroyo to the south of the station, one set was placed in desert to the west, and the last was placed near the beach to the north. Rather than checking every day, we left the traps for two nights.
The results were pleasing. We trapped more than sixty C. muricata, and ten Eleodes loretensis, along with a number of Stibia. This is an almost ideal result, in that E. loretensis is chemically defended, whereas C. muricata is not, and they are well-matched n terms of size and mass.
The traps in the arroyo were the most productive, and those in the desert also caught a good number of beetles. Interestingly, those by the beach only trapped a few Cryptoglossa.
Assuming that all goes equally well next year and we have the proper permit, we should be able to compare the temperature sensitivities of these two species that are highly similar except for the presence of chemical defense.
As always, there is more to come.