Surveillance of Host-Seeking Ticks in the Flint Hills Region (USA) and Associations with Environmental Determinants

Abstract

Diversity and phenology of host-seeking ticks were studied in the Flint Hills region of the USA, which is a prominent region for raising beef cattle. Between a two-year period from 2015–2017, ticks were collected using the dragging method from 9 distant locations, 6 of which were studied seasonally and 3 continuously throughout the study period. Of the 10,055 ticks collected, 76.5% were the Lonestar tick (Amblyomma americanum), 14% were American dog tick (Dermacentor variabilis), and 9.1% were Gulf Coast tick (A. maculatum). The blacklegged tick, Ixodes scapularis were also found, albeit in low numbers. The host-seeking activity of all three predominant tick species peaked once during the late spring, summer months in the region. The phenology of all ticks was positively associated with accumulated temperature and photoperiod. Additionally, the Normalized Vegetation Difference Index (NDVI) was associated with A. americanum, and saturation deficit and relative humidity were negatively associated with D. variabilis and A. maculatum tick phenology, respectively. This finding is useful to predict the times during a year in which cattle are at higher risk for exposure to these ticks and associated pathogens.