Lab 9 - Invasive Species and Biological Control

The invasive species and biological control lab easily becomes one of the most interesting labs of the semester. To start things off, the teaching assistant first gave his lecture over invasive species and biological controls. This included a discussion of the difference between invasive and introduced species, as well as displaying numerous picture examples of foreign and local invasive species. One of the prime examples shown that students grasped without difficulty was kudzu, due to its notorious spread across the south.

Students then proceeded to look at examples of invasive species and biological controls around the room. They also had to call upon their microscopy skills to make a wet mount of entomopathogenic nematodes and diatomaceous earth in order to view both under a microscope. The diatomaceous earth was easily seen, but the concept gave some students trouble when determining if it was a biological control. This proved to be the most asked question of the class but also the easiest answered. I would point out to the student that biological control meant a living organism was being used to control other organisms, and then I asked if the diatomaceous earth was living. From there the students were able to answer it for themselves. The topic was a good way to lead the students to find their own answer, and thus remember the path to how they got their answer later on.

The examples in the class included some living organisms, as the pictures below show. Almost in a “show and tell” fashion, the examples were spread out around the room with information sheets next to them that students had to read and examine. I say “show and tell” because bringing in specimens like a brown widow or aphids is always has a unique interest factor that peaks the students’ curiosity. By seeing the specimen up close, later on they can picture that specimen in their mind and hopefully be able to remember the role and impact it plays in the environment. As such, the lab is one of the most memorable for students for all the specimens they viewed. The only thing that could have improved this lab is perhaps adding a section in the lab manual specifically for the impact that invasive species have. Here students would read what an invasive species does to an environment and then predict what that species would do to certain crops or other environments. It would be a good way to conclude the lab and send off the students with a thought of how critically destructive invasive species can be.

Below are pictures of some of the examples that were laid out around the classroom.

The brown widow parasitoid, a biological control.

Pea aphids, an invasive species.

The eastern mosquito fish and the decapitating phorid fly, both biological controls.

The parrot feather, an invasive species.