Abstract Botflies (Diptera: Cuterebra sp.) are widely distributed and seasonally abundant parasites of small mammals in North America. To assess their effect on rodent survival, we studied the demography of botfly parasitism on small mammals in northeastern Kansas during 1995–1999. Additional comparisons on botflies parasitizing small mammals were made to a nearby old-field grid where mark–recapture studies continued from 1975 to 2003. White-footed mice, Peromyscus leucopus, were infected by botfly larvae (Cuterebra fontinella) each year during our study. The period of infection for P. leucopus was June–December, with the highest proportion of mice infected in July and August. A smaller, second peak of infection in October and November indicated that C. fontinella reproduced bimodally at this latitude with distinct summer and autumn population peaks. During the botfly seasons of the 5 years, 140 (23.3%) of 602 P. leucopus captured were infected. The percentages of individuals infected during 1995, 1996, 1997, and 1999 were not significantly different (22.4%, 17.3%, 17.1%, and 22.7%, respectively). However, in 1998, 32.4% individuals were infected with a higher incidence of multiple infections and a greater number of botfly larvae per host. Nearly half (47%) of the infected individuals caught in 1998 had infections in both summer and autumn, compared with 25% during the 1995–1997 seasons. In 1999, 63% of infected mice had at least a 2nd infection during the autumn. For all 5 years, 82%, 14%, and 4% of the infected mice had one, two, or three botflies, respectively. In 1998, 24% of the infected mice carried two or more botflies at one time, compared to 14% from 1995–1997 and 11% in 1999. Overall 94% of the infected mice were adults, with no differences between sexes. The variation seen in the prevalence of botfly parasitism of white-footed mice correlates to yearly weather fluctuations. Other demographic aspects of the infected mice, such as sex ratio, age, and longevity of those infected, did not change year to year. Our data suggest that infection with Cuterebra has little negative or positive impact upon populations of white-footed mice.

中文翻译：

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堪萨斯州白足鼠 (Peromyscus leucopus) 寄生蝇 (Cuterebra fontinella) 的人口统计

摘要 Botflies (Diptera: Cuterebra sp.) 是北美小型哺乳动物广泛分布且季节性丰富的寄生虫。为了评估它们对啮齿动物生存的影响，我们研究了 1995-1999 年间堪萨斯州东北部小型哺乳动物的蝇蛆寄生人口统计。在 1975 年至 2003 年期间，对寄生于小型哺乳动物的蝇蛆进行了额外的比较，在该网格中进行了标记-重新捕获研究。在我们的研究期间，白足鼠（Peromyscus leucopus）每年都被蝇蛆幼虫（Cuterebra fontinella）感染。P. leucopus 的感染期为 6 月至 12 月，7 月和 8 月感染的小鼠比例最高。10 月和 11 月的较小的第二个感染高峰表明 C. fontinella 在这个纬度以双峰方式繁殖，夏季和秋季人口高峰明显。在 5 年的 botfly 季节，捕获的 602 只 P. leucopus 中有 140 只 (23.3%) 被感染。1995 年、1996 年、1997 年和 1999 年期间感染的个人百分比没有显着差异（分别为 22.4%、17.3%、17.1% 和 22.7%）。然而，在 1998 年，32.4% 的个体感染了更高的多重感染发生率，并且每个宿主的蝇蛆幼虫数量更多。1998 年抓获的感染者中有近一半（47%）在夏季和秋季都有感染，而在 1995-1997 年期间这一比例为 25%。1999 年，63% 的受感染小鼠在秋季至少发生了第二次感染。在所有 5 年中，82%、14% 和 4% 的受感染小鼠分别有一只、两只或三只蝇蛆。1998 年，24% 的受感染小鼠同时携带两只或更多只蝇蛆，而 1995-1997 年为 14%，1999 年为 11%。总体而言，94% 的受感染小鼠是成年小鼠，性别之间没有差异。白足鼠蝇蛆寄生率的变化与每年的天气波动有关。受感染小鼠的其他人口统计学方面，例如受感染小鼠的性别比例、年龄和寿命，并没有逐年变化。我们的数据表明，Cuterebra 感染对白足小鼠种群几乎没有负面或正面影响。白足鼠蝇蛆寄生率的变化与每年的天气波动有关。受感染小鼠的其他人口统计学方面，例如受感染小鼠的性别比例、年龄和寿命，并没有逐年变化。我们的数据表明，Cuterebra 感染对白足小鼠种群几乎没有负面或正面影响。白足鼠蝇蛆寄生率的变化与每年的天气波动有关。受感染小鼠的其他人口统计学方面，例如受感染小鼠的性别比例、年龄和寿命，并没有逐年变化。我们的数据表明，Cuterebra 感染对白足小鼠种群几乎没有负面或正面影响。