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Submitted to: Pacific Northwest Vegetable Association Proceedings
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/1/2003 Publication Date: 11/20/2003 Citation: Munyaneza, J.E. 2003. Leafhopper identification and biology. Pacific Northwest Vegetable Association Proceedings. pp 89-91 Interpretive Summary: Leafhoppers are common pests of several agricultural crops produced in the Pacific Northwest, including carrot, potato, sugarbeet, tomato, lettuce, celery, cucumber, pumpkin, squash, and onion. Their direct feeding damage, while plant disfiguring, is minor in comparison to the damage caused to numerous vegetable crops by transmission of several important diseases, including curly top virus, aster yellows, purple top, and beet leafhopper transmitted virescence agent (BLTVA). The Columbia Basin potato growing area has recently experienced serious outbreaks of leafhopper-transmitted potato diseases. Good knowledge of the leafhopper species vectoring these diseases in potatoes and their source is needed to manage these diseases. Carrot fields in the Pacific Northwest are host to several leafhopper species, including the aster leafhopper (Microsteles fascifrons) and the beet leafhopper (Circulifer tenellus). These two leafhopper species are known to be the most serious pests of carrot because they transmit aster yellows phytoplasma and BLTVA. Both diseases can also be devastating to potatoes. Both leafhoppers species have been found to be abundant in the Pacific Northwest. Given the pest status and economic impact of the aster and beet leafhoppers in the Pacific Northwest, proper identification, knowledge of their biology, and monitoring sampling are essential to the management of these two economically important leafhopper species in vegetable crops, including potatoes and carrots. Technical Abstract: Adult aster leafhoppers are greenish yellow and are about 0.125 inch long, with transparent wings that are light smoky green to yellowish green. They are also called six-spotted leafhoppers because of the three pairs of dark spots on the top of their head. Adults are extremely active and jump, fly, or crawl away when disturbed. Primarily a desert species, the beet leafhopper is found in largest numbers and is damaging throughout the western United States from southwest Texas to Washington. Adults are about 0.125 inch long and variable in color, ranging from pale green to gray or brown color. During the summer, adults are usually uniform whitish or greenish; in fall, they acquire some dark spots dorsally, particularly on the forewings; during the winter, they become mostly dark. They can be distinguished from the aster leafhopper by the lack of the black spots on the forehead. The phenology of the aster and beet leafhoppers from sample data we collected from carrots in the lower Columbia Basin (Alderdale, WA) throughout the 2003 growing season indicated that both leafhopper species were abundant in Washington carrot fields. Both leafhoppers appear in carrots in early May and persist until late in the season. These leafhoppers are well sampled using yellow or orange sticky traps to monitor their movement to the carrot fields and sweep net samples help estimate the population density, information needed for management decision making. |
