Bot flies (Oestridae: Cuterebrinae) are obligate mammalian parasites that complete the larval stage of their life cycle under the skin of their host. Most detailed studies of bot fly larval disease ecology have been conducted in temperate deciduous zone rodent systems. To understand the relative importance of seasonal and spatial factors, as well as factors intrinsic to the host, in underpinning the likelihood and extent of parasitism by bot flies in non-rodent hosts as well as in arid-land ecosystems, we examined the dynamic for black-tailed jackrabbit (Lepus californicus) and desert cottontail (Sylvilagus audubonii) parasitism by bot fly larvae (Cuterebra spp.) across 7 repeatedly sampled sites spread across approximately 500 km of the Chihuahuan Desert ecoregion of southern New Mexico. This environment is characterized by a climate that includes hot dry summers and cool to cold dry winters, as well as strongly seasonal summer monsoonal rains. Lagomorphs are a common mid-sized mammal in these landscapes. Bot fly parasitism was strongly seasonal, with peak prevalence and abundance in the spring, and there was spatial variation in the extent of parasitism between collection sites. Additionally, jackrabbits in better body condition were less likely to be parasitized (as indicated by kidney fat index). We did not find sex-based differences in bot fly parasitism between male and female jackrabbits. Thus, in arid-land ecoregions, abiotic factors are likely the primary driver of the bot fly–host interaction, whereas factors intrinsic to the host were of secondary importance for characterizing the interactions of bot flies and lagomorphs.

肉蝇（Oestridae：Cuterebrinae）是专性哺乳动物寄生虫，在宿主皮肤下完成其生命周期的幼虫阶段。最详细的蝇幼虫疾病生态学研究是在温带落叶区啮齿动物系统中进行的。为了了解季节和空间因素以及宿主固有因素在支持非啮齿动物宿主以及干旱地区生态系统中蝇寄生的可能性和程度方面的相对重要性，我们研究了黑尾长耳大野兔 ( Lepus californicus ) 和沙漠棉尾兔 ( Sylvilagus audubonii ) 被肉蝇幼虫 ( Cuterebra spp.) 寄生在新墨西哥州南部奇瓦瓦沙漠生态区约 500 公里长的 7 个重复采样点上。这种环境的特点是气候炎热干燥，冬季凉爽至寒冷干燥，以及强烈的季节性夏季季风降雨。兔形目动物是这些地区常见的中型哺乳动物。蝇类寄生具有很强的季节性，在春季发病率和数量达到高峰，并且收集地点之间的寄生程度存在空间差异。此外，身体状况较好的长耳大野兔被寄生的可能性较小（如肾脂肪指数所示）。我们没有发现雄性和雌性长耳大野兔之间的蝇寄生存在性别差异。因此，在干旱地区，非生物因素可能是蝇类与宿主相互作用的主要驱动因素，而宿主固有的因素对于表征蝇类和兔形类动物的相互作用而言是次要的。