Pierce's Disease
Research Updates

piercesdisease.cdfa.ca.gov

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

Dispersal adaptations of immature stages of three species of leafhopper (Hemiptera : Auchenorryncha : Cicadellidae)


  • Author(s): Andersen, Peter; Mizell, Russell; Tipping, Christopher;
  • Abstract: Xylem-feeding leafhoppers have evolved several behavioral and physiological adaptations to utilize xylem fluid of variable composition, including polyphagy and high assimilation efficiency. They also display high vagility coupled with excellent visual acuity. We investigated the spectral frequency responses of the nymphal stages of three leafhopper species: Homalodisca coagulata, H. insolita, and Oncometopia nigricans. Under laboratory conditions, the nymphs of H. coagulata and O. nigricans discriminated spectra and were highly attracted to hues of yellow, with safety yellow being the most attractive. The nymphs of H. insolita were also attracted to yellow hues, but were more attracted to cream yellow. In the laboratory, maximum jumping distances of third instar H. coagulata, H. insolita, and O. nigricans were 68.0, 49.7, and 39.2 cm respectively, when provided a target. The fifth instars of H. coagulata, H. insolita, and O. nigricans had maximum jumping distances of 78.8, 29.2, and 45.5 cm, respectively. Additionally, all nymphal stages of H. coagulata dispersed up to 10 meters after three days under field conditions when released into an outdoor grass-covered arena. The neonates of H. coagulata, H. insolita, and O. nigricans survived on average, 83.5, 70.5, and 83.0 h without plant feeding, respectively.
  • Publication Date: Sep 2004
  • Journal: Florida Entomologist