Karyotypes and Meiosis of the Morabine Grasshoppers. I. Introduction and Genera Moraba, Spectriforma and Filoraba.

Abstract

Moraba, with four species, has two showing the primitive 2nB = 17 karyotype and two in which the large metacentric AB autosome has undergone dissociation into separate acrocentrics. Spectriforma, also with four species (one cytologically unknown) shows the primitive karyotype. The single species of Filoraba likewise shows 2nB = 17, but its karyotype is distinctive, since one of the small autosomes has undergone an evolutionary diminution in size and is exceedingly minute. Members of these genera all have XO males. No cytological material of Drysdalopila, the fourth genus of the tribe Morabini (Key 1977), was available.