The horn fly Haematobia irritans (Diptera: Muscidae) is a blood obligate ectoparasite of bovids that causes annual losses to the U.S. beef cattle industry of over US$1.75 billion. Climate warming, the anthropogenic dispersion of bovids and the cross-breeding of beef cattle with other bovid species may facilitate novel horn fly-host interactions. In particular, hybridizing yaks [Bos grunniens (Artiodactyla: Bovidae)] with beef cows (Bos taurus) for heterosis and carcass improvements may increase the exposure of yak × beef hybrids to horn flies. The present paper reports on the collection of digital images of commingled beef heifers (n = 12) and F1 yak × beef hybrid bovids (heifers, n = 7; steers, n = 5) near Laramie, Wyoming (∼ 2200 m a.s.l.) in 2018. The total numbers of horn flies on beef heifers and F1 yak × beef heifers [mean ± standard error (SE): 88 ± 13 and 70 ± 17, respectively] did not differ significantly; however, F1 yak × beef steers had greater total horn fly abundance (mean ± SE: 159 ± 39) than female bovids. The present report of this experiment is the first such report in the literature and suggests that F1 yak × beef bovids are as susceptible as cattle to horn fly parasitism. Therefore, similar monitoring and treatment practices should be adopted by veterinarians, entomologists and producers.

中文翻译：

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F1 y牛×肉牛（Bos grunniens×Bos taurus）杂种的嗜血性铁血寄生虫。

角蝇血红血球（Diptera：Muscidae）是牛的血液专性外寄生物，每年给美国肉牛业造成超过17.5亿美元的损失。气候变暖，人为传播的牛科动物的传播以及肉牛与其他牛科动物的杂交可能促进新的角蝇-宿主相互作用。特别是，将牛[Bos grunniens（Artiodactyla：Bovidae）]与肉牛（Bos taurus）杂交以提高杂种优势和car体品质，可能会增加牛×牛肉杂种对角蝇的暴露。本文报道了在怀俄明州拉勒米（〜2200 m asl）附近混合的牛肉小母牛（n = 12）和F1 ak牛×牛肉杂交牛（小母牛，n = 7 ；;牛，n = 5）的数字图像的收集。 2018。牛小母牛和F1 ak牛×牛小母牛的苍蝇总数[平均值±标准误差（SE）：分别为88±13和70±17]没有显着差异；但是，F1 ak牛×ste牛的牛角蝇总丰度（平均值±SE：159±39）要高于雌性牛。该实验的本报告是文献中的第一个此类报告，表明F1 ak牛×牛牛像牛一样易受角蝇寄生。因此，兽医，昆虫学家和生产者应采用类似的监测和治疗方法。该实验的本报告是文献中的第一个此类报告，表明F1 ak牛×牛牛像牛一样易受角蝇寄生。因此，兽医，昆虫学家和生产者应采用类似的监测和治疗方法。该实验的本报告是文献中的第一个此类报告，表明F1 ak牛×牛牛像牛一样易受角蝇寄生。因此，兽医，昆虫学家和生产者应采用类似的监测和治疗方法。