Written by Joe Montgomery on ksu.edu.

MANHATTAN — Climate change may have a new way of getting under your skin.

Researchers in the College of Veterinary Medicineat Kansas State University have validated a model showing growth in Kansas for the habitat of the troublesome lone star tick. Previously thought only to live in the eastern third of the state, computational modeling and live specimens have revealed the existence of these ticks as far west as Colby, which is only 55 miles from the Colorado state line.

Ram Raghavan, assistant professor in the Kansas State Veterinary Diagnostic Laboratory anddiagnostic medicine and pathobiology department, published the findings in the March 2016 issue of Vector-Borne and Zoonotic Diseases. He collaborated on the article “Maximum Entropy-Based Ecological Niche Model and Bio-Climatic Determinants of Lone Star Tick (Amblyomma americanum) Niche” with faculty from Kansas State University’s entomology and geography departments as well as other experts in the College of Veterinary Medicine.

Raghavan said the best-known diseases resulting from pathogens transmitted by the lone star tick include human monocytic ehrlichiosis and human ewingii ehrlichiosis, tularemia, southern tick-associated rash illness and feline cytauxzoonosis.

“The number of cases of feline tularemia and cytauxzoonosis in the region diagnosed at the Kansas State Veterinary Diagnostic Laboratory have increased steadily over the years, at least partly owing to the wider geographic distribution of Amblyomma americanum, or the lone star tick,” Raghavan said. “The model also suggests ongoing warming of global temperatures will likely influence the ecology and distribution of such medically important ticks, favoring more tick-borne diseases among people and pets. Climate conditions in Kansas have already been noted to have changed in noticeable ways, and many such conditions are known to favorably affect tick phenology and spatial distribution.”

Raghavan listed specific examples of climate factors.

“For instance, diurnal temperature range, a climate-change index that influenced the model, has been decreasing steadily since the 1950s,” he said. “Similarly, increased atmospheric humidity during spring and summer months over the Northern Plains was noted for roughly the same time period. Other ixodid ticks occurring in northern latitudes have already shown shifts in their distribution and abundance that have been linked to warming climate.”

Several researchers at Kansas State University and a researcher at the University of Kansas assisted with the study.