Acridoidea is the largest superfamily of grasshoppers in the order Orthoptera with over 11,000 species found on every continent except Antarctica.
Orthoptera Species File includes the following families:
Among the families Acrididae, Ommexechidae and Romaleidae there is reported to be chromosomal stability with a high frequency of species harbouring diploid number (2n) of 23âÂÂ/24â chromosomes. In species of Acrididae and Romaleidae it is common to have acrocentric chromosomes with a fundamental number (FN), i.e. number of chromosome arms, of 23âÂÂ/24âÂÂ. However, chromosomal rearrangements are frequently found as deviations from the standard acrocentric karyotype. In the subfamily Ommexechinae most species show a unique karyotype (2n = 23âÂÂ/24âÂÂ, FN = 25âÂÂ/26âÂÂ) due to the occurrence of a large autosomal pair (L1) with submetacentric morphology. There is some support for 'Mesa's hypothesis' of an ancestral pericentric inversion in the ancestor of Ommexechinae to explain this karyotype variation.