Meiswinkel R, Braack L E
Department of Entomology, Onderstepoort Veterinary Institute, South Africa.
Onderstepoort J Vet Res. 1994 Jun;61(2):155-70.
During the culling of elephants (Loxodonta africana) at five sites in the Kruger National Park, South Africa, a total of 682 Culicoides of five species of the subgenus Avaritia were found live either behind the ears of elephants or attracted to the freshly disembowelled intestinal dung of elephants. The species are Culicoides tororoensis Khamala & Kettle, 1971; C. kanagai Khamala & Kettle, 1971; C. loxodontis Meiswinkel, 1992, and two undescribed species, i.e. Culicoides sp. #50 and Culicoides sp. #54 pale form (p.f.). Of 511 female midges found behind ears, 39.9% were nulliparous, 57.3% empty parous, 2.5% freshly bloodfed and 0.2% gravid. The age composition of this subpopulation indicates that the Culicoides were behind the ears to suck blood and, furthermore, would do so in broad daylight. The age composition of 171 Culicoides of three species attracted to dung was entirely different: 1.8% nulliparous, 14.6% empty parous, and 83.0% gravid, indicating that the great majority of midges captured at dung were about to oviposit or had just oviposited. Immediately after culling, light-traps were operated at two of the sites. Of 4,023 Culicoides of 21 species captured, 93% were of the same five species found on the ears and at the dung of elephants. Using these and other unpublished data pertaining to the rearing of these five Avaritia species from elephant dung over the past seven years, we broadly sketch the life cycle of these Culicoides, the first for any Afrotropical species of the genus. We also discuss the implications the close association between elephant and midge has for the dispersal and geographic distribution of the latter, and how it may influence the involvement of midges in the transmission of diseases such as African horsesickness. Owing to difficulties in identifying species of the subgenus Avaritia in the Afrotropical Region, the taxonomy of each of the five above-mentioned species is briefly appraised. Of the remaining 16 species (7%) captured in light traps 15 (6%) belong to that sector of the genus Culicoides whose immature stages develop in groundwater habitats and include C. imicola, which comprised only 2% of the light-trap collections. The large disparity in the adult abundance patterns of the "dung" and "groundwater" species in the middle of dry bushveld, is probably the result of differences in host and larval habitat preferences, and is briefly discussed. Finally, the few reports extant on the wild-host preferences of Afrotropical Culicoides are reviewed. Five tables and five figures accompany the text.
在南非克鲁格国家公园的五个地点对大象（非洲象）进行扑杀期间，共发现682只属于阿瓦里蒂亚亚属五个物种的库蠓，它们要么活在大象耳朵后面，要么被刚开膛取出的大象肠道粪便吸引。这些物种包括1971年发现的托罗罗库蠓（Culicoides tororoensis Khamala & Kettle）、1971年发现的金贝库蠓（C. kanagai Khamala & Kettle）、1992年发现的象库蠓（C. loxodontis Meiswinkel），以及两个未描述的物种，即库蠓50号物种（Culicoides sp. #50）和库蠓54号物种淡色型（Culicoides sp. #54 pale form, p.f.）。在耳朵后面发现的511只雌性蠓中，39.9%未产过卵，57.3%已产过卵但体内无卵，2.5%刚吸食过血液，0.2%怀有身孕。该亚种群的年龄组成表明，这些库蠓待在大象耳朵后面是为了吸血，而且，它们会在大白天这么做。被粪便吸引的171只三个物种的库蠓的年龄组成则完全不同：1.8%未产过卵，14.6%已产过卵但体内无卵，83.0%怀有身孕，这表明在粪便处捕获的绝大多数蠓即将产卵或刚产过卵。扑杀后，立即在其中两个地点设置了诱虫灯。在捕获的21个物种的4023只库蠓中，93%与在大象耳朵和粪便处发现的五个相同物种一致。利用这些以及过去七年中从大象粪便饲养这五个阿瓦里蒂亚物种的其他未发表数据，我们大致勾勒出这些库蠓的生命周期，这是该属任何非洲热带物种的首个生命周期。我们还讨论了大象与蠓之间的密切关联对后者扩散和地理分布的影响，以及它可能如何影响蠓在诸如非洲马瘟等疾病传播中的作用。由于在非洲热带地区难以鉴定阿瓦里蒂亚亚属的物种，对上述五个物种的分类学进行了简要评估。在诱虫灯中捕获的其余16个物种（7%）中，15个（6%）属于库蠓属中未成熟阶段在地下水生境中发育的部分，包括伊米库蠓（C. imicola），其仅占诱虫灯捕获量的2%。在干旱灌木丛中部，“粪便”和“地下水”物种成虫丰度模式的巨大差异，可能是宿主和幼虫栖息地偏好不同的结果，并对此进行了简要讨论。最后，对现存的关于非洲热带库蠓野生宿主偏好的少数报告进行了综述。文本配有五张表格和五幅图表。
