Among the hematophagous genera, Culicoides have assumed significance and notoriety worldwide due to its ability to transmit a wide range of pathogens of public and veterinary importance . Presently India records 535.8 million as major farm animals i.e cattle, buffalo, poultry, sheep and goat including indigenous and exotic breeds, with a total bovine population of 302.8 million (buffalo, cattle, mithun, yak) . The presence of large and diverse populations of livestock increases transmission risk of bluetongue virus (BTV) by Culicoides which may lead to outbreak of bluetongue (BT). This virus causes BT in goats, sheep, cattle and other small and wild ruminants . Although the disease was dominant in temperate zones, introduction of non-native breeds in virus endemic tropical and subtropical zones also caused BT outbreak . The spread of range of BTV in the temperate was also attributed to global warming . Presently seroprevalence of BTV has been reported across all the Indian states . The BT outbreak has been witnessed frequently owing to the significant density of livestock, high prevalence of the Culicoides along with conducive climatic conditions helping in propagation of vectors and the virus [7, 8].
BTV was first recorded from the state of Maharashtra  and also occurrences of BTV from Indian states covering western, northern and southern regions followed [10, 11]. Although eastern and north eastern India is yet to witness an outbreak, high seroprevalence in livestock has appeared in several scientific articles [11, 12]. Presently 22 of the 28 serotypes (worldwide) have been recorded from India . Moreover BTV seropositivity in different animals depicts 34.0 % in bufalo, 16.0 % in caml, 38.0 % in catle, 43.0 % in goa, 39.0 % in shep and 66.0 % in mitun . The state of West Bengal shares 6.9% of total livestock population comprising of 8.3% cattle, 0.8% sheep and 10.9% goats’ population. The economy of West Bengal, especially in Burdwan district was agriculture based (mixed farming) in which livestock and animal husbandry plays a pivotal role. The villagers form a cluster of self help groups (SHG) which market livestock products to generate revenue . The seroprevalence in goat (67.0 %), shee (57.7 %) and cttle (52.0 %) has ben reported across 7 districts of West Bengal [15, 16]. Despite such high seroprevalence, BT outbreak remains unreported from West Bengal . BT outbreak and its economic implications has been well documented from the southern Indian states, however, there remains critical knowledge gaps and understanding of biology of the potent vector species prevalent in this tropical region. Few studies on biology, ecology and taxonomy of the Culicoides spp. were carried out [8, 17]. It has been reported prevalence of 7 putative vectors C. oxystoma, C. fulvus, C. orientalis, C. dumdumi, C. imicola, C. peregrinus and C. brevitarsis from southern India . In the eastern state of West Bengal, C. fulvus, C. peregrinus and C. oxystoma were the prevalent species in mixed farms and cattle sheds [8, 17] thereby posing considerable risk in the spread of disease. Further a coloured LED light trap based extensive surveillance program was also conducted in the same site to ascertain the prevalence of the aforesaid species in the cattle sheds .
Information available on host seeking activity, ecology and biology of Culicoides are limited across the globe [19, 20]. The aforesaid information was imperative for implementation of control measures in disease epidemiology . Although the disease causing pathogens vectored by Culicoides were a matter of concern, relatively scant information on its bionomics exists in India  and Europe [20, 21, 22]. In the light of forecasting disease transmission, limited information on the host-vector association has led to assumptions that all the Culicoides species prevalent in the cattle sheds fed on host with equal facility on which various predictions were based . Difficulty in aspirating Culicoides from the host body also limits studies on host seeking activity of the Culicoides .
In the present study the catch data obtained by two different methods (light trap and aspirator) were evaluated and compared in order to separate two adult activity of Culicoides spp. in real time: flight activity and biting activity. The midges may undertake flight for foraging, mating, seeking of resting place or to oviposit. Biting activity points to the association of vectors to its host, probable route of transmission of disease depicted. The two study sites were selected at Burdwan district of West Bengal due to report of seroprevalence of BTV from this region  as well as high seasonal abundance of potent vector species of Culicoides associated with livestock from this district . Moreover, the evaluation enables validation of the time and preferential landing of Culicoides on cattle body parts which is critical at farmer’s level to reduce the host-vector contact.