title: Spatial and temporal dynamics of overwintering Homalodisca coagulata (Hemiptera: Cicadellidae).
abstract: A 4-yr landscape-scale study was conducted to investigate spatial and temporal dynamics of overwintering Homalodisca coagulata (Say) (Hemiptera: Cicadellidae) in the lower San Joaquin Valley, California. Spatial structures of H. coagulata distributions were characterized with Moran's I index, and spatial associations between H. coagulata and the surrounding environment were investigated with a geographic information system. H. coagulata was caught consistently with sticky traps throughout the winter, and trap catches formed a distinctive peak in December or January, indicating active flight of H. coagulata during the winter. In 2000-2001, the mean +/-SE trap count was 4.8 +/- 1.21 per trap per wk, and H. coagulata trap catches were spatially autocorrelated within approximately 1.3 km. Approximately 49% of H. coagulata were caught in citrus, 23% in stone fruit, and 11% in grape. After a control program began in spring 2001, the mean trap count was considerably lower (0.041 +/- 0.0004 per trap per wk), and no spatial autocorrelations were detected in 2001-2004. H. coagulata trap catch-crop associations also changed after initiation of the control program. Between 25 and 38% of H. coagulata trap catches were from citrus, between 8 and 20% were from stone fruit, and between 11 and 25% were from grape. Potential for winter-season spread and management of Xylella fastidiosa Wells et al., a pathogen causing Pierce's disease, are discussed.
authors.affiliation: Department of Entomology, University of California, Riverside, CA 92521, USA.
authors.forename: Yong-Lak
authors.initials: YL
authors.lastname: Park
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Perring
authors.forename: Rosie
authors.initials: R
authors.lastname: Yacoub
authors.forename: David W
authors.initials: DW
authors.lastname: Bartels
authors.forename: David
authors.initials: D
authors.lastname: Elms
mesh_terms: D000818:Animals; D002140:California; D016208:Databases, Factual; D003710:Demography; D006430:Hemiptera / Q000502:physiology*; D007303:Insect Vectors; D010935:Plant Diseases / Q000382:microbiology*; D011156:Population Density; D012621:Seasons; D013997:Time Factors; D027843:Vitis; D044167:Xylella