title: Influences of weather on Ixodes scapularis nymphal densities at long-term study sites in Connecticut.
abstract: Tick species worldwide are implicated in transmission of pathogens that cause mild to severe diseases in humans and livestock. Although tick population densities are often highly correlated with tick-borne disease rates, we currently know little about which factors underlie annual changes in those tick population densities. We used a 25-year dataset of Ixodes scapularis drag-sampling surveys at two locations in CT, USA, to investigate the relationship between average nymphal density from mid-May to mid-August and monthly, lagged regional weather variables. The dataset was randomly split into two data subsets, one for hypothesis development and one for hypothesis testing. Nymphal density showed the strongest association with the Standardized Precipitation Index for January of the same year that density data were collected in the analysis based on the hypothesis development data subset. This association was positive; nymphal tick density increased with regional winter precipitation. Nymphal density was positively associated with this same weather variable in the hypothesis testing data subset. Weather conditions during the coldest months of the year may serve as a bottleneck to tick populations, thereby functioning as an important correlate of not only annual blacklegged tick nymphal densities the following summer, but also entomological risk associated with tick-borne pathogens transmitted by this species.
authors: Department of Entomology, The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT 06504-1106, United States. Electronic address: laura.hayes@ct.gov.
authors: Laura E
authors: LE
authors: Hayes
authors: Department of Community Medicine, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030-6325, United States.
authors: Jennifer A
authors: JA
authors: Scott
authors: Department of Entomology, The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT 06504-1106, United States.
authors: Kirby C
authors: KC
authors: Stafford
mesh_terms: D000818:Animals; D001096:Arachnid Vectors / Q000254:growth & development*; D025065:Borrelia burgdorferi / Q000502:physiology*; D003237:Connecticut / Q000453:epidemiology; D006801:Humans; D018884:Ixodes / Q000254:growth & development*; D008193:Lyme Disease / Q000382:microbiology / Q000635:transmission*; D009758:Nymph; D011156:Population Density; D012621:Seasons; D017282:Tick-Borne Diseases / Q000382:microbiology / Q000635:transmission*; D014887:Weather
keywords: Borrelia burgdorferi; Ixodes scapularis; Standardized Precipitation Index; Tick-associated disease; Winter precipitation