The effects of algae leaf coverage and flow rate on oviposition choice in Calopteryx maculata

Abstract

Female Calopteryx maculate are endophytic egg layers; they place their eggs within floating aquatic vegetation. In this study artificial oviposition leaf patches were created and placed in different sites along the Maple River near Pellston, MI. The varying flow rates were recorded and after 48 hours the leaf patches were collected. The egg number or oviposition sites were counted on each leave along with the percent algae leaf coverage. The effect of algae leaf coverage and flow rate on oviposition preference were statistically measured; algae leaf coverage did not affect oviposition frequency (p>0.05) and intermediate stream flow was preferred over slower and faster flow rates as oviposition sites (p<0.05). The reason for this correlation is unknown, however, it could relate to the optimal conditions for egg growth and development. It is impossible to know whether oviposition flow‐rate preference is the result of the male or female’s choice. More research of egg development and observational data would provide more insights into the reasoning for intermediate flow oviposition preference.