A parthenogenetic species of grasshopper with complex structural heterozygosity (Orthoptera: Acridoidea).

A rare species of morabine grasshopper (Moraba virgo Key, sp. nov.) is described from New South Wales. This is the only known all-female member of the Acridoidea, reproducing exclusively by parthenogenesis. It has a karyotype of 15 chromosomes, heterozygous for various rearrangements, including a pericentric inversion, several fusions, and a dissociation; these rearrangements are not quite the same in the three known colonies of the species. The mechanism of parthenogenesis involves a premeiotic doubling of the chromosome number, followed by a normal meiosis in which pairing is restricted to sister-chromosomes, so that there are 15 structurally homozygous bivalents.