RANA, RAJINDER SINGHTHAKUR, PRIYANKA2019-08-052019-08-052019-07http://krishikosh.egranth.ac.in/handle/1/5810119233ABSTRACT Himachal Pradesh is one of the hubs of biological diversity with varied agro climatic conditions and elevation ranging from 350 to 7000m amsl. The congenial atmospheric conditions are the natural abode and homeland for large number of insects. Despite being one of the most diverse habitats, several insect families remain poorly studied in the state. Cicadellidae one of the largest insect families of order Hemiptera distributed worldwide is one among them. The diversity, species richness, abundance and distribution pattern os f leafhopper speciein all the four agro-climatic zones of the state was explored. The sweep net as well as light traps were used for collecting leafhoppers from all the 12 districts of the state covering 25 locations. A total of 85 leafhoppers species belonging to 61 genera of 12 subfamilies of Cicadellidae were recorded. Of these four species, Gurawa monorcephala Pruthi, Leofa pulchellus Distant, Olidiana kirkaldyi (Walker) and Paralimnellus cingulatus (Dlabola) from subfamilies appeared to be new records from Himachal Pradesh and one species, Pseudosubhimalus sp. 1 was recorded to be new from India. Species richness of leafhopper species increased with the altitude with a hump of the highest species richness as well as diversity in the mid hills zone (651-1800m amsl) following declining trend towards the cold dry zone. Morphological characters taken under consideration for identification of leafhopper species which included: crown, face, compound eyes, ocelli, frontoclypeus, pronotum, scutellum, hind tarsi, hind tibial spinulation, forewing appendix and venation. The male genitalia was the key and the most important taxonomic feature for species identification based on the variation in distinguished features of pygofer, valve, subgenital plate, style, connective and aedeagus. Checklist for the leafhopper species of Cicadellidae collected from all the four agro-climatic zones of Himachal Pradesh was prepared along with the lists of economically important leafhopper species that are well known pests of crops as well as vectors of serious plant pathogenic diseases. The photographs of each recorded specimen were provided along with the diagnostic keys which were prepared for their identification. The distribution of the species might be very useful in future to sketch good pest management practices and policies designed specifically for the particular region. The information generated through this study will be useful for further revision and taxonomical updating of higher level classification of leafhopper fauna of the hill statefor their identification.ennullThesis