Leafhoppers

Leafhopper are found in warm, dry regions of North America. They are wedge-shaped, can be up to 3mm long and are green to greenish-yellow to brown. Nymphs are similar to adults except they lack fully developed wings. Leafhoppers have a wide host range, including numerous weeds and vegetables. They have sucking mouth parts, and feed on phloem tissue, leaving pale, circular spots or peppery specks in leaves. Adult females make hatch cuts across leaf veins and stems to insert eggs. The life cycle can be completed in 40-45 days if environmental conditions favorable In California, leafhoppers overwinter in weeds, especially those in the foothills of the Sierra Nevada and Coast ranges. In the spring, as weeds die out, leafhoppers move into adjacent tomato fields.

The beet leafhopper (Circulifer tenellus), vectors the curly top virus. This virus is picked up and transmitted persistently by inmature and adult stages of the insect. Once acquired, the virus is carried to the next instar stage, and can be transmitted throughout the adult life. Beet curly top does not multiply in the vector, nor is it carried to the next generation via the egg. The California Department of Food and Agriculture conducts yearly surveys of beet leafhopper and conducts a spray program for eradication of this vector to help manage curly top disease in tomatoes. The common brown leafhopper, Orosius argentatus, vectors big bud, a disease cause by phytoplasma.