Guglielmone A A, Volpogni M M, Quaino O R, Anziani O S, Mangold A J
Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela, CC 22, CP 2300 Rafaela (Santa Fe), Argentina.
Parasite. 2001 Dec;8(4):369-73. doi: 10.1051/parasite/2001084369.
The seasonal distribution of Haematobia irritans (Linnaeus, 1758) was evaluated at 31 degrees 12' S-61 degrees 29' W, Santa Fe, Argentina from November 1992 to August 2000 by weekly fly counts on 20 Holstein cows not treated against ectoparasites. The analysis was mainly focused on winter fly abundance. Two peaks of abundance were found from spring to autumn. Adults of H. irritans were consistently found on cattle during winter, with increasing numbers from the end of July to late August. The only climatic parameter soundly correlated with the four week period, before each winter fly count, was the mean air temperature with the exception of year 1998. No significant relationship was found between level of cow infestation and relative humidity, saturation deficit and rainfall. Horn fly infestation on cows was lower than 20% from end of June to end of August only in 1995, when mean air temperature was consistently lower than 11 degrees C during the four week period previous to most fly counts. Conversely, the mean temperature was higher than 12 degrees C previous to fly counts in 1998, when most cows remained infested. The results indicate that a proportion (unknown) of immature stages of H. irritans were insensitive to diapause inducing factors and developed through winter.
1992年11月至2000年8月，在阿根廷圣达菲南纬31度12分、西经61度29分的地区，通过对20头未进行体外寄生虫防治的荷斯坦奶牛每周进行苍蝇计数，评估了血蝇（Linnaeus，1758）的季节分布。分析主要集中在冬季苍蝇的数量上。从春季到秋季发现了两个数量高峰。冬季期间，在牛身上始终能发现血蝇成虫，从7月底到8月底数量不断增加。除了1998年外，在每次冬季苍蝇计数前四周，唯一与苍蝇数量密切相关的气候参数是平均气温。在奶牛的感染水平与相对湿度、饱和差和降雨量之间未发现显著关系。仅在1995年，6月底至8月底奶牛的角蝇感染率低于20%，当时在大多数苍蝇计数前的四周内平均气温持续低于11摄氏度。相反，1998年在苍蝇计数前平均气温高于12摄氏度，当时大多数奶牛仍受到感染。结果表明，血蝇的一部分（未知比例）未成熟阶段对滞育诱导因素不敏感，并在冬季发育。
