Fleas are common ectoparasites of vertebrates worldwide and vectors of many pathogens causing disease, such as sylvatic plague in prairie dog colonies. Development of fleas is regulated by environmental conditions, especially temperature and relative humidity. Development rates are typically slower at low temperatures and faster at high temperatures, which are bounded by lower and upper thresholds where development is reduced. Prairie dogs and their associated fleas (mostly Oropsylla spp) live in burrows that moderate outside environmental conditions, remaining cooler in summer and warmer in winter. We found burrow microclimates were characterized by stable daily temperatures and high relative humidity, with temperatures increasing from spring through summer. We previously showed temperature increases corresponded with increasing off-host flea abundance. To evaluate how changes in temperature could affect future prairie dog flea development and abundance, we used development rates of O. montana (a species related to prairie dog fleas), determined how prairie dog burrow microclimates are affected by ambient weather, and combined these results to develop a predictive model. Our model predicts burrow temperatures and flea development rates will increase during the twenty-first century, potentially leading to higher flea abundance and an increased probability of plague epizootics if Y. pestis is present.

跳蚤是全世界脊椎动物的常见体外寄生虫，也是许多致病病原体的载体，例如土拨鼠群中的森林鼠疫。跳蚤的发育受环境条件的调节，尤其是温度和相对湿度。发展速度通常在低温下较慢，在高温下较快，这受到发展减少的下限和上限的限制。土拨鼠及其相关的跳蚤（主要是Oropsyllaspp) 生活在缓和外部环境条件的洞穴中，夏季保持凉爽，冬季保持温暖。我们发现洞穴微气候的特点是每日温度稳定，相对湿度高，温度从春季到夏季不断升高。我们之前表明温度升高与离宿主跳蚤丰度的增加相对应。为了评估温度变化如何影响未来土拨鼠跳蚤的发育和丰度，我们使用了O. montana的发育率（一种与土拨鼠跳蚤有关的物种），确定了土拨鼠洞穴微气候如何受到环境天气的影响，并结合这些结果开发了一个预测模型。我们的模型预测洞穴温度和跳蚤发育率将在 21 世纪增加，如果存在鼠疫耶尔森氏菌，则可能导致跳蚤数量增加和鼠疫流行的可能性增加。