Homalodisca coagulata (Hemiptera, Cicadellidae) transmission of Xylella fastidiosa to almonds

• Author(s): Almeida, Rodrigo; Purcell, Alexander;
• Abstract: Almond leaf scorch is a disease caused by Xylella fastidiosa, a xylem-limited bacterium transmitted by leafhopper sharpshooters. We studied some characteristics of Homalodisca coagulata transmission of X. fastidiosa to almonds. The susceptible almond variety Peerless was used for the experiments. H. coagulata adults were collected on citrus in Bakersfield CA. Acquisition efficiency of X. fastidiosa from infected almonds was low: 3/30, 2/30 and 1/30 individually tested insects transmitted to healthy plants after acquisition access periods of 1, 2 and 4 days respectively. After a 4-day acquisition access period on infected almonds, groups of 4 H. coagulata were transferred to healthy plants. Efficiency of transmission per group was 16, 27 and 51%, for 1, 2 and 4 days of test plant access period respectively. Groups of 4 infective insects were also caged on 1-year-old wood or green shoots of almonds; plants inoculated in both tissues became symptomatic.
• Publication Date: Jun 2002
• Journal: Phytopathology