The Larval Plate Assay

Abstract

The larval plate test has been used by researchers as a choice test to study the response of terrestrial larvae to various external cues. We describe here a laboratory exercise using third instar larvae of wild-type Drosophila to study the response toward multiple cues including olfactory as well as physical environmental cues such as light. The experiment can be easily carried out in an undergraduate lab and does not require any sophisticated instruments or equipment. The results of a series of experiments indicate the extent of response that each of the cue generates relative to the other. The highlight of the article however is the pre-lab discussion that can be done with students by putting forth various possible designs followed by discussion regarding the benefits and/or errors that could creep into the results obtained by using a particular design. Such a discussion would prove to be helpful in enhancing student understanding of experimental design, especially in designing experiments in animal behavior. The article also includes an extended theoretical problem set that can be used by facilitators in an undergraduate classroom activity.