Morphological and genetic diversity studies among populations of tea mosquito bug, Helopeltis theivora from Assam, India.

Abstract

Multilocus DNA fingerprinting and morphometry were compared to evaluate genetic diversity of tea mosquito bug, Helopeltis theivora Waterhouse (Hemiptera: Miridae). Eighty-one female individuals representing 27 populations of H. theivora from tea plantations of different regions of Assam, India were collected and evaluated. Observation of 12 characters i.e. body length, antennae length, head width, stylet length, thorax width, forewing length, forewing width, hind wing length, hind wing width and length of foreleg, middle leg, hind leg revealed distinct pattern in different population of H. theivora. On the basis of morphological traits, six different types of population groups have been identified. Genetic analysis produced a total number of 262 bands, of which 221 (84.35 %) were polymorphic. The number of bands produced per primer varied from 2 to 17. The dendrogram derived from UPGMA cluster analysis indicates three clusters containing 24 populations at 63 % of similarity while three populations viz. H23, H19 and H14 excluded from the major cluster and come out as a discrete cluster. The cluster 1 includes populations from 9 different districts of Assam, cluster 2 again included 5 populations, cluster 3 constitute 3 populations and cluster 4 again consist of 3 populations. Both marker (morphological and molecular) systems indicated that genetic variability within populations examined was significantly high. Appropriate quality and quantity of chemical pesticides used in pest control programmes is a fundamental goal in the tea industry. It is supported by the knowledge of patterns of population connectivity and historical demography.