Two new grasshopper species in the texanus group of the genus Melanoplus(Orthoptera : Acrididae : Melanoplinae) with biological notes on the group

摘要

Melanoplus alexanderi n. sp. from South-Central Texas Counties centered around Bastrop County and Melanoplus dakini n.sp. from west central Louisiana are described. These two short wing species are part of the 7 member allopatric Melanoplus texanus species group. Distinguishing structure, distribution, habitat, food preferences and egg pods are described and compared. Evidences for hybridization between Melanoplus warneri, having the neo-XY + 10 pairs autosomes karyotype, and Melanoplus angularis, having the XO + 11 pairs of autosomes karyotype, are noted. Characteristics of populations of intergrades between Melanoplus angularis and Melanoplus dakini in four far southeast Texas (Jasper, Newton, Sabine and San Augustine Counties) are delineated.