Meiotic studies in two species of chrysopids (Chrysopidae: Neuroptera)

Abstract

The spermatogenesis of two chrysopids, Chrysoperla argentina and C. Externa, used as biological controls of numerous agricultural plagues, was analyzed based on cytological studies. They are characterized by a simple system of sex determination XY (n = 5A + XY). The sexual chromosomes show positive heteropicnosis during early prophases and distance segregation in latter stages. The comparative analysis performed between the two species show similar cytological behavior to other neuropterous insects.