Recent epidemics of Pierce’s disease of grapevine in California vectored by Homalodisca coagulata (Say), an invasive vector species, have characteristics that differ from epidemics involving native vectors. Among these differences are the longer distances and greater speed that the disease is spread by H. coagulata. In this investigation, we used yellow sticky traps to study the seasonal dispersion activity of H. coagulata in a southern California grape-growing area in which an epidemic of Pierce’s disease has caused large losses. For 21 mo, we monitored adult H. coagulata at the edges of vineyards bordering citrus, an important crop host, natural coastal sage scrub vegetation, and natural riparian vegetation. We also monitored H. coagulata dispersion from 0 to 40 m into vineyards. Finally, we examined the vertical dispersion of H. coagulata adults into grapevines through a season. This investigation showed that H. coagulata is associated with citrus, from where it disperses deep into vineyards, and not just the vineyard edge as with Pierce’s disease vectors that are native to California. Peak dispersion into vineyards occurred in the summer. Another period of H. coagulata activity occurred in the winter in vineyards bordering citrus. Through the period of peak flight activity, 97% of all H. coagulata adults trapped between 1 and 7 m were caught at an altitude of 5 m or lower, suggesting the potential of a barrier as a management tactic to keep H. coagulata out of vineyards.
Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.