ARS | Publication request: Seasonal Population Dynamics of Draeculacephala minerva (Hemiptera: Cicadellidae) and Transmission Efficiency of Xylella fastidiosa

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 15, 2008
Publication Date: August 15, 2008
Citation: Cabrera-La Rosa,, J., Johnson,, M., Chen, J., Civerolo, E.L., Groves,, R. 2008. Seasonal Population Dynamics of Draeculacephala minerva (Hemiptera: Cicadellidae) and Transmission Efficiency of Xylella fastidiosa. Journal of Economic Entomology. 101(4):1105-1113.

Interpretive Summary: The green sharpshooter is a very common and often abundant grass-feeding leafhopper in California. Its population dynamics and ability to transmit the Pierce’s disease bacterium were monitored over a 2-year period in California’s San Joaquin Valley. Collections of green sharpshooters from natural populations breeding within irrigated pastures and alfalfa fields adjacent to almond leaf scorch affected orchards indicated the occurrence of three discrete generations per year that peaked during the summer months. Insects captured on intercepting various trap types indicated local movement of these insects into surrounding affected orchards. Local dispersal and transmission of the bacterium indicated that this insect may be partly responsible for the slow spread of the almond leaf scorch (ALS) pathogen recently observed in California’s San Joaquin Valley. Our primary focus in this research has been to accurately identify the natural vectors of the ALS pathogen. This research has provided fundamental, research-based information to document which vector species transmit the ALS pathogen, where they likely acquire the pathogen, when they move into orchards, and when they spread the pathogen to almonds.

Technical Abstract: The green sharpshooter, Draeculacephala minerva Ball, is a very common and often abundant grass-feeding leafhopper in California. Its population dynamics and ability to transmit Xylella fastidiosa were monitored over a 2-year period in California’s San Joaquin Valley. Collections of individuals from natural populations breeding within irrigated pastures and alfalfa fields adjacent to X. fastidiosa-infected almond orchards indicated the occurrence of three discrete generations per year that peaked during the summer months. Population densities varied significantly among experimental field survey sites. Insects captured on intercepting mesh traps, yellow sticky cards, and UV-light traps indicated local movement of these insects into and surrounding X. fastidiosa-infected, almond orchards. Local movement and seasonal transmission efficiency indicated that this insect may be partly responsible for the slow spread of almond leaf scorch now recently observed in California’s San Joaquin Valley.