Grillet M E, Barrera R, Conn J
Instituto de Zoología Tropical, Universidad Central de Venezuela, Caracas.
Med Vet Entomol. 1995 Apr;9(2):195-201. doi: 10.1111/j.1365-2915.1995.tb00178.x.
Simulium metallicum sibling species E was identified cytotaxonomically from an onchocerciasis focus at Altamira in northern Venezuela. S. metallicum E larvae were sampled monthly from two small mountain streams over a 15-month period (July 1990 to September 1991) and eleven habitat variables were measured at two altitudes. One stream consistently harboured much higher densities of S. metallicum E larvae than the other, with three annual peaks of abundance: during the dry season and at the beginning and end of the rainy season. These peak densities were correlated with high rainfall 4 months previously. Larvae were most abundant on submerged rocks and fallen leaves, in small shallow areas characterized by slow water current, high conductivity and sparse terrestrial vegetation cover. Stream variables which best explained the temporal changes in abundance were water discharge and conductivity. The population dynamics of S. metallicum E appeared to be influenced primarily by interactions between stream discharge and substrate stability. Relevance of these results to vector control with larvicides is discussed.
金属蚋E姐妹种是通过细胞分类学方法，从委内瑞拉北部阿尔塔米拉的盘尾丝虫病疫源地鉴定出来的。在15个月的时间里（1990年7月至1991年9月），每月从两条山间小溪采集金属蚋E幼虫，并在两个海拔高度测量11个栖息地变量。其中一条小溪中金属蚋E幼虫的密度始终比另一条小溪高得多，有三个年度丰度峰值：分别出现在旱季以及雨季的开始和结束时。这些峰值密度与4个月前的高降雨量相关。幼虫在淹没的岩石和落叶上最为丰富，分布在水流缓慢、电导率高且陆地植被覆盖稀疏的小而浅的区域。最能解释丰度随时间变化的溪流变量是水流流量和电导率。金属蚋E的种群动态似乎主要受溪流流量与底物稳定性之间相互作用的影响。本文讨论了这些结果与使用杀幼虫剂进行病媒控制的相关性。
