MSc

Leafhoppers are one of the important groups of insect pests on agricultural crops. Vegetables and rice crop are subjected to infestation by a number of leafhopper species, leading to heavy economic loss. These leafhoppers suck sap from crops and inject toxic saliva into plant tissues resulting in hopper burn symptoms. They also cause damage when they oviposit into plant tissues. Some species act as vectors of plant pathogens viz., viruses, phytoplasmas, spiroplasmas and bacteria Eg. rice green leafhoppers. Nielson (1985) reported 151 species of leafhoppers as vectors of plant diseases and nearly 70 per cent of insect species transmitting plant disease agents are leafhoppers. The present study on “Diversity of leafhopper fauna associated with rice and vegetable ecosystems” was undertaken at Department of Agricultural Entomology, College of Horticulture, Vellanikkara during 2014-16 with the objectives to document the diversity of leafhoppers in rice and vegetable ecosystems in Thrissur district and to develop a dichotomous taxonomic key for their identification.
Purposive surveys were carried out in the Kole lands of Thrissur district and Paddy fields of Vadakkanchery for collecting leafhoppers in rice ecosystem. Leafhoppers were collected from vegetable crops like brinjal, bitter gourd, ash gourd, cowpea, lab lab bean and okra, in major vegetable growing tracts of Thrissur district. Leafhoppers collected from field were sorted out into different groups based on the morphological characters and mounted on card points using insect gum. Wings and genitalia were dissected out and studied. Drawings were made using camera lucida attached to research microscope (Olympus BX 51, 100x). Photographs were taken using stereomicroscope with digital camera attached (binocular stereo zoom microscope- Leica EZ4 HD, 35x). Based on the characters studied and species identified, a dichotomous taxonomic key was prepared for the identification of leafhopper species associated with rice and vegetable ecosystems. A total of 17 species of leafhoppers were collected from rice and vegetable ecosystems belonging to three subfamilies, eight tribes and 12 genera. One species belonging to tribe Erythroneurini of subfamily Typhlocybinae could not be identified.
Nine species of leafhoppers belonging to two sub families, viz, Cicadellinae (Tribe: Cicadellini- two species) and Deltocephalinae (Chiasmini- three species, Deltocephalini- one species, Hecalini- two species and Stenometopiini- one species) were collected from rice ecosystem. Seven species of leafhoppers were collected from rice plants viz, Cofana spectra (Distant), C. lineata (Distant), Nephotettix nigropictus (Stal), N. virescens (Distant), Exitianus indicus (Distant), Maiestas dorsalis (Motschulsky) and Hecalus porrectus (Walker). Another two species, viz., H. lutescens (Distant) and an unidentified species of leafhopper in the genus Doratulina were collected from the weed Eragrostis tenella Linn. associated with rice ecosystem. Occurrence of Hecalus lutescens (Distant) is a new record for Kerala. Cofana lineata and Hecalus porrectus are new records on rice in Kerala.
The survey on leafhopper fauna associated with vegetable ecosystem revealed the presence of eight species belonging to three sub families, Cicadellinae (Tribe Cicadellini- one species), Deltocephalinae (Tribe Opsiini- one species) and Typhlocybinae (Tribe- Empoascini-three species, Tribe- Erythroneurini- three species). These leafhoppers were found associated with six major vegetable crops. Amrasca biguttula biguttula (Ishida) on brinjal and okra, Empoasca (Empoasca) kerri Pruthi on cowpea, E. (E.) motti Pruthi on bitter gourd, Seriana jaina (Distant) on cowpea, Tautoneura (Tautoneura) mayarami Mathew and Ramakrishnan on lab lab bean, Kolla ceylonica (Melichar) on brinjal, okra and cowpea, Hishimonus phycitis (Distant) on brinjal and an erythroneurine species (unidentified) on brinjal and ash gourd. Infestation of K. ceylonica (Melichar) on brinjal, okra and cowpea is a new record for Kerala.
Mathew (2004) had listed 154 species of leafhoppers from Kerala. Present study added two more species. Considering the rich flora of Kerala, this number is meagre. Hence detailed survey on all agro climatic zones is required to enrich the database on leafhopper fauna of Kerala.