Steelman C D, Gbur E E, Tolley G, Brown A H
Department of Entomology, University of Arkansas, Fayetteville 72701.
J Med Entomol. 1993 Mar;30(2):414-20. doi: 10.1093/jmedent/30.2.414.
Weekly estimates of populations of horn fly, Haematobia irritans (L.), were made on individual purebred Charolais, Chianina, Hereford, Polled Hereford, and Red Poll cows in 1988, 1989, and 1990 with Angus included in 1989 and 1990. During the study period, 94 of approximately 200 individual cows were classified as either fly resistant or fly susceptible. In general, individuals retained the same classification over the 3-yr study period. The mean number of flies on individual susceptible cows in all breeds was at least twice the number of flies on resistant cows. Susceptible Chianina cows averaged > 4.5 times as many flies as resistant cows of the same breed. Individual cows within all breeds classified as fly resistant ranged in age from 2 to 12 yr, whereas fly-susceptible cows ranged in age from 2 to 14 yr; therefore, cow age did not influence the abundance of horn flies on individual cows within breeds. Two-year-old fly-resistant cows were identified accurately according to their horn fly-population density, showing the potential of host resistance in horn fly-population management.
1988年、1989年和1990年，对夏洛来、契安尼娜、赫里福德、无角赫里福德和红白花牛等纯种母牛个体的角蝇（Haematobia irritans (L.)）数量进行了每周估计，1989年和1990年的估计中还包括安格斯牛。在研究期间，约200头个体母牛中有94头被分类为抗蝇或感蝇。总体而言，在3年的研究期内，个体保持相同的分类。所有品种中个体易感母牛身上的苍蝇平均数量至少是抗性母牛身上苍蝇数量的两倍。易感契安尼娜母牛身上的苍蝇平均数量是同品种抗性母牛的4.5倍以上。所有品种中被分类为抗蝇的个体母牛年龄在2至12岁之间，而感蝇母牛年龄在2至14岁之间；因此，母牛年龄不影响各品种内个体母牛身上角蝇的数量。两岁的抗蝇母牛根据其角蝇种群密度被准确识别，这表明宿主抗性在角蝇种群管理中的潜力。
