Survey, Distribution Patterns and Abundance of Pyrgomorphid Fauna (Orthoptera: Pyrgomorphidae) in Agro-ecosystems of South Western Rajasthan

Abstract

Survey conducted in the five districts of Rajasthan viz., Banswara, Dungarpur, Rajsamand, Sirohi and Udaipur during 2005-06 and 2006-07 under the present investigation indicated that five species of short homed grasshoppers belonging to the family Pyrgomorphidae were regularly abundant in the agro-ecosystems. The diversity comprised four genera (Chrotogonus, Atractomorpha, Pyrgomorpha and Poekilocerus) and five species i.e. Chrotogonus trachypterus (Blanchard), Chrotogonus oxypterus (Blanchard), Atractomorpha crenulata Fabricius, Pyrgomorpha bispinosa Walker and Poekilocerus pictus Fabricius. The genus Chrotogonus, represented by C. trachypterus (33.34±7.63) and (C. oxypterus 29.45±6.93), were relatively more abundant in Udaipur district than in the other four districts surveyed. The species A. crenulata (07.09±1.66) and P. bispinosa (06.35±1.54) had a relatively equal representation in all the districts, but their numerical abundance was a little more in the district Banswara as compared to the other four districts surveyed. The species P. pictus (07.00±2.82) was relatively more in district Rajsamand and was not recorded from the district Banswara. The mean hopper population of the surface grasshopper species C. trachypterus and C. oxypterus was relatively more in Udaipur district with a respective mean population of 6.50 and 5.58 per 25 stops followed by that in Sirohi (5.17 & 4.80/ 25 stops). They were least abundant in Banswara (4.10 & 3.73 25 stops) district during both the years. The hoppers of the genus Atractomorpha was almost equally represented in all the five districts surveyed. However, their population was relatively more in Banswara district (3.83/ 25 stops). The genus Pyrgomorpha also had a similar representation from all the five districts surveyed, though the hopper population was relatively more at Banswara with a mean population of (3.42 hoppers/ 25 stops). The hopper population of Poekilocerus was relatively more in district Rajsamand with 2.43 hoppers per 25 stops.