Seasonal Incidence of Indigenous Leafhoppers (Homoptera: Cicadellidae) on Corn and Several Winter Crops in Mississippi1

Abstract

At least 36 species of leafhoppers were collected on corn and from plots of winter grasses and grains (oat, ryegrass, wheat, and bahia grass) in the vicinity of State College, Miss., in 1965–66. Of the 33 that were found on corn (30 species in 1965, 26 in 1966), 12 were sufficiently numerous so that each constituted 1% or more of each season's total leaf hopper collections. The other 21 (15 species in 1965, 14 in 1966) were considered miscellaneous species which occurred only incidentally on corn. Graminella nigrifrons (Forbes) and Macrosteles fascifrons (Stal) accounted for 36.5% and 12.5%, and 54.0% and 23.0%, of the total seasonal leafhopper collections in 1965 and 1966, respectively. They were the predominant species in both years, and were collected during every semimonthly collection period. In general, leafhopper populations on corn reached high levels in late May and June, declined in July, and increased to high levels again in August and September. Bahia grass was an excellent winter host for M. fascifrons , but most leafhoppers preferred oat and ryegrass. G. nigrifrons , M. fascifrons , Deltocephalus sonorous Ball, and Balclutha sp. were the predominant leafhoppers during the winter. Five other species— Exitianus exitiosus (Uhler), Draeculacephala portola Ball, D. balli Van Duzee, Empoasca sp., and Aceratagallia sp.—were present in the test area throughout the year. Agallia constricta Van Duzee, Carncocephala flaviceps (Riley), Stirellus bicolor (Van Duzee), and Chlorotettix viridius (Van Duzee), on the basis of seasonal occurrence and population levels on corn, are other species which may be considered of significance in investigations of possible vectors of corn stunt virus.