Leafhopper is any member of the family Jassidae, which includes a very large number of small bugs greatly varying in form and often grotesque. Leafhoppers are especially numerous in grass and grain, which they are believed to injure to a greater extent than is usually supposed. Among the best-known species is the grape-vine leafhopper (Erythroneura vitis), which is often so abundant in vineyards that the leaves may turn brown from- the insects punctures. They have been effectively caught by lapping the vines to make the insects jump against a screen smeared with tar or a fan similarly covered and kept in constant motion close lo the vines. This species of leafhoppers is sometimes erroneously called «thrips.» Among the best known of the grass-feeding host of species is the destructive leafhopper (Cicadula or Limotettix exitosa). This is somelimes caught in wide pans covered with tar and dragged across the field.