Submitted to: International Congress of Entomology
Publication Type: Abstract Only
Publication Acceptance Date: 1/27/2016
Publication Date: 7/1/2016
Citation: Sisterson, M.S., Wallis, C.M., Krugner, R., Stenger, D.C. 2016. Egg maturation by the glassy-winged sharpshooter (Hemiptera: Cicadellidae); a vector of Xylella fastidiosa. International Congress of Entomology. Available: https://esa.confex.com/esa/ice2016/meetingapp.cgi/Paper/111154.
Technical Abstract: Rates of spread of insect-transmitted plant pathogens are a function of vector abundance. Despite this, factors affecting population growth rates of insects that transmit plant pathogens have received limited attention. The glassy-winged sharpshooter (Homalodisca vitripennis) feeds on xylem-sap and has a broad host range. As a result, the glassy-winged sharpshooter is capable of transmitting the xylem-limited bacterial pathogen Xylella fastidiosa, which causes disease in a wide range of perennial crops. Studies to identify factors affecting egg production by the glassy-winged sharpshooter have been conducted over the past decade. Results indicate that females emerge without mature eggs and must feed to produce mature eggs. During oviposition events, females deposit the majority of their egg load, thereby requiring another feeding bout to produce additional mature eggs. Low levels of feeding (<12 ml of excreta) were associated with an increase in female dry weight and body lipid content, but little egg production. As levels of feeding increased (>12 ml of excreta), females diverted resources to egg production. As a result, there was an exponential relationship between feeding (as measured by excreta production) and egg load. Rates of egg maturation varied with host plant species, suggesting that host plant species vary in quality for providing nutrients to produce mature eggs. Xylem-sap chemical profiles of plants used in egg maturation assays vary, although it is unclear if differences in egg maturation rates were due to feeding stimulants, feeding deterrents, or quantity of limiting compounds.