Department of Animal Health, NEIKER-Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Bizkaia, Spain.
Applied Zoology and Animal Conservation Research Group, Department of Biology, University of the Balearic Islands (UIB), Palma de Mallorca, Spain.
Parasit Vectors. 2022 Jun 11;15(1):199. doi: 10.1186/s13071-022-05297-5.
Aquatic ecosystems provide breeding sites for blood-sucking insects such as Culicoides biting midges (Diptera: Ceratopogonidae), but factors affecting their distribution and host choice are poorly understood. A study was undertaken at two nature reserves in northern Spain to examine the abundance, species composition, population dynamics and feeding patterns of biting midges between 2018 and 2019.
Culicoides were captured by light suction traps baited with CO and by sweep netting vegetation. Blood meals and species identification of blood-fed specimens were determined using cytochrome c oxidase I subunit (COI) DNA barcoding. Multivariate generalized linear models were used to evaluate the associations between the abundance of Culicoides, the species richness and other parameters.
The 4973 identified specimens comprised 28 species of Culicoides. These included two species reported for the first time in northern Spain, thus raising to 54 the number of Culicoides species described in the region. Specimens of all 28 species and 99.6% of the total specimens collected were caught in suction traps, while sweep netting vegetation revealed just 11 species and 0.4% of the total specimens. Midge abundance peaked in June/early July, with five species comprising > 80% of the captures: Culicoides alazanicus (24.9%), Culicoides griseidorsum (20.3%), Culicoides poperinghensis (16.2%), Culicoides kibunensis (10.7%) and Culicoides clastrieri (9.6%). DNA barcode analysis of blood meals from eight Culicoides species revealed that they fed on 17 vertebrate species (3 mammals and 14 birds). Species in the subgenus Avaritia were primarily ornithophilic, except for C. griseidorsum and C. poperinghensis. Host DNA from blood meals was successfully amplified from 75% of blood-fed females. A pictorial blood meal digestion scale is provided to accurately assess the blood-fed status of female Culicoides.
The large number of different blood meal sources identified in the midges captured in this study signals the likely importance of wild birds and mammals (e.g. red deer and wild boar) as reservoir/amplifying hosts for pathogens. Available hosts are more exposed to being bitten by biting midge populations in aquatic ecosystems in late spring and early summer.
水生生态系统为吸血昆虫（如库蠓属吸血蠓，双翅目：蠓科）提供了繁殖场所，但人们对影响它们分布和宿主选择的因素知之甚少。本研究于 2018 年至 2019 年在西班牙北部的两个自然保护区进行，以检查吸血蠓的丰度、物种组成、种群动态和摄食模式。
使用 CO 诱饵的光吸力陷阱和扫网采集植被来捕获库蠓。使用细胞色素 c 氧化酶 I 亚基（COI）DNA 条形码确定吸血标本的血餐和物种鉴定。使用多元广义线性模型评估库蠓丰度、物种丰富度和其他参数之间的关联。
鉴定出的 4973 个标本包括 28 种库蠓。其中包括在西班牙北部首次报道的两种，从而使该地区描述的库蠓物种数量增加到 54 种。所有 28 种和 99.6%的总采集标本均在吸力陷阱中捕获，而扫网采集植被仅发现 11 种和 0.4%的总采集标本。蠓类丰度在 6 月/7 月初达到峰值，有 5 种占总捕获量的 80%以上：阿拉扎尼库蠓（24.9%）、灰色库蠓（20.3%）、波佩林根库蠓（16.2%）、基布恩库蠓（10.7%）和克拉斯特里库蠓（9.6%）。对 8 种库蠓的血餐 DNA 条码分析表明，它们以 17 种脊椎动物（3 种哺乳动物和 14 种鸟类）为食。亚属 Avaritia 的物种主要是嗜鸟性的，除了灰色库蠓和波佩林根库蠓。从 75%的吸血雌性中成功扩增出了血液餐中的宿主 DNA。提供了一个直观的血液餐消化尺度，以准确评估雌性库蠓的吸血状态。
本研究中捕获的吸血蠓中鉴定出的大量不同的血液餐来源表明，野生鸟类和哺乳动物（如马鹿和野猪）作为病原体的储存/扩增宿主可能很重要。在春末和初夏，水生生态系统中的吸血蠓种群可能会使可用宿主更容易受到叮咬。
