Leafhopper

Leafhopper (patafading) name applied to the numerous species of plant-sucking insects of the family Cicadellidae (=Jassidae), order Homoptera. Over 15,000 species of leafhoppers are known worldwide. They are of various forms, colours, and sizes. They rarely exceed 13 mm in length, and many are only a few millimetres. They have sucking type of mouthparts with four piercing stylets (the mandibles and maxillae). The beak arises from the back of the head. They have four wings, the front wings are slightly thickened and the hind wings membranous. Many are marked with beautiful colour pattern. Antennae are very short, bristle like. They have one or more rows of small spines extending the length of hind tibiae.

Leafhoppers occur on almost all types of plants, including forest, shade and orchard trees, shrubs, grasses, and many field and garden crops. There are many economically important pest species in this group and more than 150 species are known to infest different crops and economic plants in Bangladesh. From rice crop alone nearly 25 species have been described.

Leafhoppers cause injury to plants in a number of different ways. Some species remove excessive amount of sap and reduce or destroy the chlorophyll in the leaves. Some species interfere with the normal physiology of the plant by mechanically plugging the phloem and xylem vessels in leaves so that transport of food materials is impaired. Many leafhopper species act as vectors of organisms that cause plant diseases. Tungro disease of rice, potato yellow dwarf, maize stunt and maize chlorotic dwarf virus, tobacco mosaic etc are transmitted by the leafhoppers. Some species cause stunting and leaf curling that results from the inhibition of growth on the under surface of the leaves where the leafhoppers feed.

Some of the most notable pest species of different crops recorded in Bangladesh are the rice green leafhopper, Nephotettix virescens and N. nigropictus; Zigzag leafhopper, Recilia dorsalis, organge-headed leafhopper, Thaia oryzivora; tea green fly, Empoasca flavescens; patato leafhopper, Amrasca devastans (also attacks cotton, okra, chilli etc); and mango hopper, Idioscopus atkisoni, I. clypealis and I. niveosparsus.

Being a very large family, Cicadellidae is often divided into as many as 19 subfamilies by some authorities. Most leafhoppers have a single generation a year, but a few have two or three. Under favourable environmental conditions some species may build up enormous population in short time and produce a typical feeding damage symptom known as 'hopperburn'. [SM Humayun Kabir]

See also rice.