Synopsis

The availability of resources is an important consideration when studying the reproductive behaviors of animals and the survival of offspring. When environmental conditions result in limited resources, juvenile growth and offspring survival may be poor due to limited food resources and competition for those resources. In response to limited resources animals will often change reproductive patterns in an attempt to enhance reproductive success. One adaptive strategy seen in a number of insect species is to produce more eggs and/or larger eggs when environmental conditions do not favorably support larval growth and offspring survival.

In this laboratory exercise, students will design and implement experiments examining the impact of limited resources on egg production and egg laying behavior of C. maculatus. Typical student experiments included observing female egg laying behavior and the collection of data on the number of eggs laid and the size of eggs laid. This experiment could be extended to allow students to evaluate the success of the female egg laying strategies by examining parameters such as emergence success and offspring size.

Topic: Reproductive Behavior, Ecology

Level: Introductory – Upper-level majors

Class time: One 2-3 hour class period plus 2-3 hours one week later

Mary Byrne and Kimberly Heiman

Biology Department, Muhlenberg College, Allentown PA 18104