Development of Ischnura verticalis (Coenagrionidae: Odonata): Effects of Temperature and Prey Abundance

Abstract

Increased food availability increased rate of development within an instar, head width ratio (ratio of headwidth of later instar over head width in previous instar), and weight per unit head width of newly molted larval Ischnura verticalis (Say) (Coenagrionidae: Odonata) reared in the laboratory. Temperature affected rate of development but not weight per unit head width or head width ratio. Mortality was not affected by any treatment. Rate of development was negatively correlated with both weight per unit head width and head width ratio. Results suggest that the developmental process has evolved to reduce risks associated with small size at the expense of a more rapid development.