Synopsis

Female bean beetles discriminate among different beans during oviposition. The choice that they make influences the growth and survivability of their offspring. Typically they show a preference for natal beans, however even among a large selection of different beans they favor a particular subset. The question is how do beetles determine an appropriate bean on which they could lay their eggs. This experiment ideally follows an experiment where students determine that female bean beetles are somewhat choosy in regards to their prey bean. In this experiment, students are encouraged to design an experiment where they determine what sensory structures would be important in discriminating among bean species. By prompting them to think about how they discriminate the qualities of items in their environment, they can explore the role that beetle sensory structures play in discriminating bean qualities. Experiments that examine sensory detection include ablation of antenna, distal or whole antenna, ablation of the palps, and/or painting of the eyes. Evaluation of the role of sensory structures includes examining on which beans eggs are laid and changes in the placement of the eggs.

Topic: Sensory Systems

Level: Introductory – Intermediate majors

Class time: One class period of 1.5 hours to set up experiment and another class period of 2 hours to collect and analyze data. The experiment runs 48 hours and for a once a week lab, students can remove the beetles at that time and collect their data on their assigned lab day.

Barbara Musolf

Department of Natural Sciences, Clayton State University, Morrow, GA 30260