Diversity, Morphometry and Phylogenetic relationship of Orthopterans in Coimbatore, Tamil Nadu, India

Abstract

Orthopterans are important components of a wide range of habitats and key players in ecological processes. Understanding the distribution of species in ecosystem is an important step for identifying biodiversity hotspots and designing effective conservation strategies. The main objectives of this research work is to evaluate the status of Orthopterans community and to characterize the different morphometric and genetic relationship of dominant acridids in Coimbatore, Tamil Nadu, India. Orthopterans were collected using the sweep net and handpicking method. Different diversity indices and morphometric parameters were calculated using MS Excel, PAST and SPSS software. Based on the landmark coordinates, the wing shape of acridids were examined using morphometric software namely tps-Util, tps-Dig, tps-Relw and tps-Small. Phylogenetic relationship of acridids was assessed using MEGA and DAMBE software. Overall, 45 Orthopterans were collected under 16 subfamilies and four families from the different regions and seasons of the study area. The highest species diversity was recorded from the family of Acrididae and subfamily of Oedipodinae. Simpson index, Shannon diversity index and Margalef richness were recorded maximum in site I (Marudhamalai) during monsoon season. Totally, 38 host plants of Orthopterans were collected under 16 families from the study area. Orthopterans were recorded maximum in the host plant, Cynodon dactylon and minimum in Ipomea pes tigridis. Highest number of Orthopterans were recorded in the Poaceae family. Correlation coefficient showed a positive relationship between plant and Orthopterans composition. Population dynamics of acridids were noted high in site I during monsoon season and acridids population positively correlated with rainfall. The morphometric parameters such as body length, head length, pronotum length, antenna length, fore wing length and hind femur length showed inter-and intra-specific variation among acridids. Totally, 19 homologous landmarks were identified in the wing of ac