Sex ratio and the chromosomes of Apus aecqualis Packard (Phyllopoda, Crustacea)

Abstract

In this paper are described the results of the observations on the sex ratio and the chromosomes of Apus aecqualis (Fam. Apodidae) collected from a paddy field in the suburb of Numazu, Sizuoka-ken. Of 43 individuals collected, 34 were males, and 9 females. It has previously been reported that the males are rare in the member of this family, but the data at hand are incompatible with this general rule since there occur more males than females.
It was found that the spermatogonial complement contained 12 chromosomes which consisted of a pair of large V-shaped elements and 5 pairs of small rod and V-shaped ones. The chromosomes are generally very small in size.