A Characterization of the Egg Capsules of Anacroneuria starki and A. talamanca (Plecoptera: Perlidae), with a Suggestion about the Distribution of Stoneflies in the Tropics

In this study, the structure of egg capsules of two species of Neotropical Perlidae: Anacroneuria starki FENOGLIO and MORIS1 (2001a) and A. talamanca STARK (1998), were examined. Eggs were studied using a scanning electron microscope. A morphological characterization of these eggshells is presented: layers, attachment structures and other anatomical features are described. The egg capsules of the two species differ in some aspects, but both are characterized by thin-layered egg coverings (vitelline envelope, chorion and extrachorion). On the basis of these observations, the importance of eggshell structure for the biogeographical distribution of Plecoptera in the tropics is discussed. A key role for egg capsules in the adaptation process of Plecoptera to aquatic environments of the Neotropics is hypothesized.