Culicoides imicola (Culicoides imicola Kieffer, former name C. pallidipennis Carter) is a species of Ceratopogonidae that transmits the bluetongue virus (BTV) and the African horse sickness virus. This particular species has been recorded in Africa, Asia and Europe. African midges feed on animal blood, including horse, cattle, and sheep. Unlike other species within the Culicoides genus, this species prefers drier habitats for egg laying but retains a preference for moist soil to support larvae growth. Other suspected BTV vectors are Culicoides (Culicoides) pulicaris and species in the Culicoides (Avaritia) obsoletus complex.
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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starts withThere are many species in the family, and it is difficult to physically distinguish between them. This has historically been a source of confusion in studies involving C. imicola.
Historically, Culicoides imicola has been found in Africa and southwestern Asia, but their distribution has been increasing, as human activity has catalyzed this spread. Because of the connection between cattle and C. imicola, C.imicola can be found where cattle are densely populated. Coupled with irrigation in farms which provides damper more habitable soil, C.imicola population has been able to rise.
Unlike other species of Culicoides, C. imicola has been shown to prefer drier environments in multiple studies. A likely reason is that C. imicola pupa are especially prone to drowning, so their eggs are often laid in surfaces free of running water. However, the larvae need moist soil, so there tends to be a trade-off between dry and wet areas.
There are 4 main stages of development: egg, larvae, pupa, and imago. Eggs are laid in batches and darken quickly once laid.
The life cycle of C. imicola depends largely on the temperature at which pregnant females lay their eggs. In laboratory-tested flies, it was found that at 20 °C it takes up to 2 months to go from egg-laying to adulthood, up to 21 days at 25 °C, and up to 16 days at 28 °C. However, at higher temperatures there were fewer hatchings and higher variability in fecundity. It is also interesting to note that more males emerge from pupae than females, although the exact reasons are unknown. Some possible explanations are that the female larvae have higher mortality rates, or that the sex ratio is temperature dependent.
Culicoides imicola, like most other biting midges, feed on animal blood. In Africa, C. imicola is known to feed on horse, cattle, and sheep. Nonetheless, their feeding preferences haven't been studied extensively in Europe but should be similar to those in Africa.
Culicoides imicola and humans usually do not interact directly, but they do so through their capabilities as disease vectors for many farm animals such as cows, horses, and sheep. Cattle drives have thus been identified as a man-made mechanism for the spread of infectious disease vectors, such as C. imicola. These vectors rely on cattle dung, and their introduction into different areas has led to C. imicola and viral spread across the world.
