Steelman C D, Brown A H, Gbur E E, Tolley G
Department of Entomology, Arkansas Agricultural Experiment Station, University of Arkansas, Fayetteville 72701.
J Econ Entomol. 1991 Aug;84(4):1275-82. doi: 10.1093/jee/84.4.1275.
Statistically significant differences were observed in the population density of the horn fly, Haematobia irritans irritans (L.), on different breeds of beef cattle. The European breed Chianina had a population density of horn flies generally less than or equal to 50% than that of the British cattle breeds (Angus, Hereford, Polled Hereford, and Red Poll) and another European breed (Charolais). Generally, no significant difference existed among numbers of horn flies on Hereford, Polled Hereford, and Red Poll cows in 1988 or among Angus, Hereford, Polled Hereford, and Red Poll cows in 1989. Factors other than color appeared to be involved in the selective process between the horn fly and its host. Population densities on two white European breeds (Charolais and Chianina) were significantly different on all weekly intervals except for 4 wk in both 1988 and 1989. No significant difference existed among Charolais and British breeds except during 4 wk in 1988 and 3 wk in 1989. When weaning weights of all calves were adjusted for the effects of age to 205 d, sex of calf, and age of dam, the indirect effect of the horn fly on weaning weight showed a significant linear regression. Each 100 flies per cow caused a reduction of 8.1 kg in calf weaning weight. Cows within each breed with low numbers of horn flies weaned significantly heavier calves than cows with higher numbers of horn flies.
在不同品种的肉牛上，观察到角蝇（Haematobia irritans irritans (L.)）的种群密度存在统计学上的显著差异。欧洲品种契安尼娜牛的角蝇种群密度通常比英国肉牛品种（安格斯牛、赫里福德牛、无角赫里福德牛和红白花牛）以及另一个欧洲品种夏洛莱牛的种群密度低50%或更低。一般来说，1988年赫里福德牛、无角赫里福德牛和红白花牛的角蝇数量之间以及1989年安格斯牛、赫里福德牛、无角赫里福德牛和红白花牛的角蝇数量之间没有显著差异。除颜色外，其他因素似乎也参与了角蝇与其宿主之间的选择过程。在1988年和1989年，除了4周外，两个白色欧洲品种（夏洛莱牛和契安尼娜牛）在所有每周间隔的种群密度都有显著差异。除了1988年的4周和1989年的3周外，夏洛莱牛和英国品种之间没有显著差异。当对所有犊牛的断奶体重进行调整，以消除年龄至205天、犊牛性别和母牛年龄的影响时，角蝇对断奶体重的间接影响显示出显著的线性回归。每头母牛多100只角蝇会使犊牛断奶体重减少8.1千克。每个品种中角蝇数量少的母牛所产犊牛的断奶体重显著高于角蝇数量多的母牛所产犊牛。
