Female ticks (Ixodes scapularis) infected with Borrelia burgdorferi have increased overwintering survival, with implications for tick population growth

We demonstrate that adult ticks (Ixodes scapularis) infected withBorrelia burgdorferi, the bacterium that causes Lyme Disease, have greater overwintering survival than uninfected ticks.Adult ticks were placed in individual microcosms and allowed to overwinter. In the spring we collected the ticks and tested both dead and living ticks forB. burgdorferi DNA. We also performed lab tests to show that we could accurately identifyB. burgdorferi DNA in ticks 10 weeks after their death. The study was repeated over 3 years, and infected ticks were more likely to survive the winter than uninfected ticks in each of the 3 winters in two different microclimates (i.e., dune grass and forest). Increased overwintering survival of infected ticks will lead to an enrichment of infected adult ticks in the early spring relative to the fall, and this has important public health implications. Moreover, the increased winter survival of adult female ticks could have a large impact on tick population growth. Our results suggest that, in addition to climate change,B. burgdorferi infection itself may be promoting the northern range expansion ofI. scapularis. This is a novel insight. Our study highlights how pathogens could promote host range expansion. AbstractThe tick,Ixodes scapularis, vectors pathogens such asBorrelia burgdorferi, the bacterium that causes Lyme disease. Over the last few decadesI. scapularis has expanded its range, introducing a novel health threat into these areas. Warming temperatu...
Source: Insect Science - Category: Biology Authors: Tags: ORIGINAL ARTICLE Source Type: research