I am one of the Applied Plant Ecology fellows this summer at the San Diego Zoo Institute for Conservation Research. My project is to establish baseline arthropod diversity in a planned coastal sage scrub restoration at San Diego County’s Lake Hodges. In other words, we want to know what’s out there currently, so that years down the road, after restoration is complete, the plant ecology scientists will be able to see what has changed. This project is part of a larger experiment that aims to determine the ecological effects of the shrub diversity in coastal sage scrub restoration.
The restoration project will begin this fall. The site has been marked out with 11 X 11-meter plots, which will each receive a certain number of species of native plants, ranging from none (control) to 8. The arthropod samples focused on the extremes: control, one species, and eight species.
We started by collecting arthropods using pitfall traps and pan traps. This was done in mid-June. The traps had to stay open for exactly 24 hours. Unfortunately, we had issues with animal and human interference with our traps, which meant that we had to exclude over a quarter of our samples from our analysis. Then all of our specimens were sorted by morphospecies, meaning that those that look the same are assumed to be the same species even if we weren’t sure what exactly they were. This, of course, is not always accurate; some males and females of the same species can look completely different (sexual dimorphism) or some species can look very similar to each other. We then attempted to identify each morphospecies to the family level.
We just finished with the long process of identifying and are now in the process of analyzing what it all means. Currently, there should be no difference between future treatment sites; however, when they sample again after restoration is complete, there will, theoretically, be very clear differences between plots with no restoration, plots with one shrub species, and plots with eight shrub species.
Here are some of our most exciting finds so far:
Tarantula hawk: Pompilidae
The female uses her powerful stinger to immobilize a tarantula and drag it back to her nest. Then she lays an egg in the tarantula. When the larva hatches, it eats its way out. Their sting has a relatively low mortality rate in humans (honey bees are higher), but it is supposed to be one of the most painful! Fortunately, they are not very aggressive.
Fairyfly wasp: Mymaridae
This family contains the smallest known flying insects. This little guy is no bigger than the tip of the ballpoint pen in the corner of the picture. I found him tangled in the legs of another bee when I was looking at it under the microscope.
Flies are very difficult to identify (for me, anyway). Does anyone out there know what this is?
Samantha Bussan is an Applied Plant Ecology fellow at the San Diego Zoo Institute for Conservation Research.