Submitted to: CAPCA Adviser Magazine
Publication Type: Trade Journal
Publication Acceptance Date: 5/20/2004
Publication Date: 6/20/2004
Citation: Phillips, P.A., Damsteegt, V.D., Brlansky, R.H. 2004. The glassy-winged sharpshooter is confirmed as a vector of CVC. CAPCA Adviser Magazine. May/June 2004. pp 22-25. Interpretive Summary: Citrus variegated chlorosis (CVC) is a bacterial disease of citrus that is not found in the United States and is transmitted by several species of leafhopper insects. One species, Homalodisca coagulata, the glassy-winged sharpshooter, has become a serious pest of grapes and citrus in California. It is a good transmitter of the bacterial agent that causes Pierce's disease of grape. We tested the ability of this insect to transmit the causal agent of CVC. Adult sharpshooters were collected in California and shipped overnight to Ft. Detrick, MD where transmission experiments were conducted in a biologically safe containment facility. It was important to transport the insects on young, rooted citrus seedlings to maintain water transport pressure for the insects. The glassy-winged sharpshooters were shown to be inefficient transmitters of CVC.
Technical Abstract: Citrus variegated chlorosis (CVC), a bacterial disease of citrus that is not found in the United States, is caused by Xylella fastidiosa. It is transmitted by several species of leafhoppers. The glassy-winged sharpshooter (leafhopper) (Homalodisca coagulata) has become a serious pest of grapes and citrus in California and is an efficient vector of the strain of X. fastidiosa causing Pierce's disease of grapes. In a study jointly coordinated among the USDA, University of Florida, and University of California, adult glassy-winged sharpshooters from California were shipped directly from the field to Fort Detrick, MD, where transmission studies were conducted in a BSL3-P greenhouse facility. Survival of the sharpshooters was strongly influenced by the type of carrier plants during shipment to reduce moisture stress for the insect. Breaks in xylem pressure and lack of active pumping of xylem exudates by the insects lead to increased mortality. The glassy-winged sharpshooter was shown to be a vector of CVC although the efficiency of transmission was relatively low.