Distribution and preferred plants. The red-headed sharpshooter, Xyphon (formerly Carneocephala) fulgida, along with the green sharpshooter, is considered to be one of the important species of insect vectors for Pierce’s disease and alfalfa dwarf diseases in California’s Central Valley. It occurs from Mexico and western Arizona north to northern California. It is similar in appearance to the green sharpshooter but is smaller and has reddish coloration on the pointed crown of its head. This sharpshooter also occurs in coastal areas in grasses and sedges along streams. Although it has been found on numerous species of grasses and sedges, by far its most common host plant for feeding and laying eggs is Bermuda grass (Cynodon dactylon). It inserts small groups of eggs just below the leaf epidermis of its host grasses. Its most common habitats in California are ditch banks, orchard cover crops; weedy hay fields and permanent irrigated pastures, anywhere that its preferred grasses continue to grow throughout the year. It can also be found on grasses in sunny areas of riparian zones. The red-headed sharpshooter prefers more open or sparser plant growth on drier soils than the green sharpshooter. The red-headed sharpshooter may be found in small patches of Bermuda grass along roadsides, ditches, or the margins of alfalfa fields where the grass growth is not succulent or dense enough to support high populations of the green sharpshooter. Like the green sharpshooter, it is only rarely seen feeding on grape. It flies for a short period (30-45 minutes) at dusk until full darkness and can be found at nearby lights at this time. Its role as a Pierce’s disease vector is based on the consistent occurrence of its breeding habitats near vineyards.
In Baja California, Mexico, the red-headed sharpshooter is the most important vector for Pierce’s disease on sandy, heavily irrigated soils where Bermuda grass is lush throughout the growing season. Control of Bermuda grass eliminates high populations of the vector.
Life cycle. There are usually four generations per year in central California. Eggs of each generation are laid in mid-March, mid-May, early July, and mid-August. Approximately 25 days are required for development from egg to adult. Adults are active during winter, but they are much less abundant and more widely scattered than green sharpshooter adults during this time.
Control: Spatial patterns of the occurrence of Pierce’s disease in vineyards shows that most disease is spread by red-headed or green sharpshooters flying into vineyards from nearby (usually adjacent) vector breeding areas such as irrigated pastures, weedy alfalfa fields or ditch banks. Grasses within vineyards do not seem to be a major problem in spreading Pierce’s disease if the grasses die out or are removed by cultivation in fall or winter. Bermuda grass are breeding hosts of the green and the red-headed sharpshooters, and may contribute to the spread of Pierce’s disease if they harbor overwintering adults within the vineyard.
For more infomation. You may find more details on the red-headed sharpshooter and its relation to Pierce’s disease, in the reference section by referring to scientific papers by DeLong and Severin 1949; Freitag and Frazier, 1946; Goodwin and Purcell, 1992;Hewitt et al., 1942; 1949; Purcell and Frazier, 1985.