Kar Surajit, Mondal Biswajit, Ghosh Joydeep, Mazumdar Shuddhasattwa Maitra, Mazumdar Abhijit
Entomology Research Unit, Department of Zoology, The University of Burdwan, Burdwan, West Bengal 713104, India.
Tata Consultancy Services, Ecospace 2A, AA II, Newtown, West Bengal 700135, India.
Acta Trop. 2022 Nov;235:106648. doi: 10.1016/j.actatropica.2022.106648. Epub 2022 Aug 9.
Determination of host choice of Culicoides species (Diptera: Ceratopogonidae), the vectors of bluetongue virus (BTV), is pivotal to ascertain the role of each species in the transmission of pathogens, pest management and enumeration of disease prediction models. Host preference of livestock associated Culicoides midges was investigated in West Bengal, India with four replicates of a 3 × 3 Latin square design during August and September 2021. Adult Culicoides were mouth aspirated from three BTV hosts viz., cattle, sheep and goats. Mouth aspirating was validated by the sweep net collections. The host-baited collections recorded seven Culicoides species; with the highest landing rate on cattle (n = 5,667; 92.9%) followed by sheep (n = 365; 6.0%) and goat (n = 67; 1.1%). Based on the Jacob's selectivity index, all midge species, except for Culicoides fulvus Sen & Das Gupta, encountered, preferred cattle over other mammalian hosts. Culicoides oxystoma Kieffer, the subgenus Trithecoides Wirth & Hubert and Culicoides actoni Smith, predominated on the ventral region (belly/flank) of the cattle. However, Culicoides peregrinus Kieffer and C. actoni were observed to be prevalent in the leg region of sheep. A significantly higher percentage of female (99.9%) with only 0.3% of male were trapped in aspiration based animal baited collections. On the other hand sweep net and light trap catch comprises of 50.7%, 89.7% female and 49.2%, 10.2% male respectively. Surprisingly, DNA based blood meal analysis revealed human blood from the midges trapped in UV-LED light traps. Supplying the first evidence that Culicoides similis Carter, Ingram & Macfie, C. fulvus and Culicoides palpifer Das Gupta & Ghosh, feed on humans.
库蠓属（双翅目：蠓科）是蓝舌病病毒（BTV）的传播媒介，确定其宿主选择对于明确每种库蠓在病原体传播、害虫管理及疾病预测模型计数中的作用至关重要。2021年8月至9月，在印度西孟加拉邦，采用3×3拉丁方设计进行了四次重复实验，对与家畜相关的库蠓的宿主偏好进行了研究。从牛、羊和山羊这三种BTV宿主身上用口吸法采集成年库蠓。通过扫网采集对口吸法进行了验证。宿主诱捕采集记录到七种库蠓；落在牛身上的比率最高（n = 5667；92.9%），其次是羊（n = 365；6.0%）和山羊（n = 67；1.1%）。根据雅各布选择性指数，除了富库蠓（Sen & Das Gupta）外，所有捕获的蠓种都更喜欢牛而不是其他哺乳动物宿主。尖喙库蠓（Kieffer）、特里特库蠓亚属（Wirth & Hubert）和阿克托库蠓（Smith）主要集中在牛的腹部（腹部/侧腹）区域。然而，观察到远飞库蠓（Kieffer）和阿克托库蠓在羊的腿部区域较为常见。在基于动物诱饵的口吸法采集中捕获的雌性库蠓比例显著更高（99.9%），雄性仅占0.3%。另一方面，扫网捕获和灯光诱捕捕获的雌性分别占50.7%、89.7%，雄性分别占49.2%、10.2%。令人惊讶的是，基于DNA的血餐分析显示，在紫外线发光二极管诱捕器中捕获的蠓体内有人类血液。这首次证明了相似库蠓（Carter、Ingram & Macfie）、富库蠓和触须库蠓（Das Gupta & Ghosh）会以人类为食。
