Pierce's Disease
Research Updates


What is Pierce's Disease?

Pierce's Disease is a bacterial infection, which is spread by bugs that feed on grapevines, particularly the "glassy winged sharpshooter." Grapevines that become infected with PD can quickly become sick and die.

glassy-winged sharpshooter

Egg Load Dynamics of Homalodisca vitripennis

  • Author(s): Sisterson, MS;
  • Abstract: Homalodisca vitripennis, the glassy-winged sharpshooter, poses a serious threat to grape production because of its ability to vector Xylella fastidiosa, the causal agent of Pierce's disease. The glassy-winged sharpshooter is native to the southeastern United States, and over the last 20 yr has expanded its range into Texas and California and more distantly into French Polynesia. A better understanding of the reproductive dynamics of H. vitripennis will aid in assessment of the invasiveness of this insect and may aid in refinement of control strategies. First, females of known age were dissected to determine egg maturation schedules. Females did not produce mature eggs until at least 1 wk after adult emergence. Oviposition reduced the number of mature eggs carried by females, suggesting a continuous cycle of egg deposition followed by egg maturation where females may experience transient egg limitation. Second, males and females were monitored over their entire lifetimes to determine longevity and fecundity. Males,Old females were long lived with all average lifespan of 4 mo. Females displayed one of three temporal patterns of oviposition: (I) no oviposition, (2) oviposition began <40 d after emergence, or (3) oviposition began >40 d after emergence. In general, oviposition was independent of female age. Finally, egg maturation rates of field-collected females were determined. Egg maturation rates varied with time of year and maximum egg maturation rates coincided with periods when oviposition was expected to be high. The highest egg maturation rate observed was five eggs per female per day.
  • Publication Date: Oct 2008
  • Journal: Environmental Entomology