Circadian activity of Culicoides oxystoma (Diptera: Ceratopogonidae), potential vector of bluetongue and African horse sickness viruses in the Niayes area, Senegal

Abstract

Culicoides biting midges (Diptera: Ceratopogonidae) are important vectors of arboviruses in Africa. Culicoides oxystoma has been recently recorded in the Niayes region of Senegal (West Africa) and its high abundance on horses suggests a potential implication in the transmission of the African horse sickness virus in this region. This species is also suspected to transmit bluetongue virus to imported breeds of sheep. Little information is available on the biology and ecology of Culicoides in Africa. Therefore, understanding the circadian host-seeking activity of this putative vector is of primary importance to assess the risk of the transmission of Culicoides-borne pathogens. To achieve this objective, midges were collected using a sheep-baited trap over two consecutive 24-h periods during four seasons in 2012. A total of 441 Culicoides, belonging to nine species including 418 (94.8 %) specimens of C. oxystoma, were collected. C. oxystoma presented a bimodal circadian host-seeking activity at sunrise and sunset in July and was active 3 h after sunrise in April. Daily activity appeared mainly related to time periods. Morning activity increased with the increasing temperature up to about 27 °C and then decreased with the decreasing humidity, suggesting thermal limits for C. oxystoma activity. Evening activity increased with the increasing humidity and the decreasing temperature, comprised between 20 and 27 °C according to seasons. Interestingly, males were more abundant in our sampling sessions, with similar activity periods than females, suggesting potential animal host implication in the facilitation of reproduction. Finally, the low number of C. oxystoma collected render practical vector-control recommendations difficult to provide and highlight the lack of knowledge on the bio-ecology of this species of veterinary interest.Electronic supplementary materialThe online version of this article (doi:10.1007/s00436-015-4534-8) contains supplementary material, which is available to authorized users.

Abundance, diversity and temporal activity of adult Culicoides spp. associated with cattle in West Bengal, India

“…The temporal activity of C. peregrinus , C. oxystoma and C. fulvus observed here is similar to that observed for those species in Australia(Bellis et al ., ) although our finding further suggests that C. fulvus is more nocturnal than Australian populations. Crepuscular activity of C. oxystoma has also been noted in Senegal, with a feeding preference for horses and sheep (Fall et al ., , ). Several factors such as trap type, time of sampling, location of the trap relative to the breeding site and the presence of hosts in the vicinity of the trap can influence the catch composition (Mullens, ).…”

Spatial distribution modelling of Culicoides (Diptera: Ceratopogonidae) biting midges, potential vectors of African horse sickness and bluetongue viruses in Senegal

“…Both the Institut Sénégalais de Recherches Agricoles (ISRA) team and veterinary services’ officers carried out trapping over two consecutive collection nights in each site at the end of the rainy season (between September and October). This timeframe was chosen because it corresponds to the peak of abundance of Culicoides in the Niayes region [ 13 – 15 , 28 ]. Geographical coordinates of sampling sites (Fig.…”

The effect of ambient temperature fluctuations on Culicoides biting midges population dynamics and activity in dairy farms: a longitudinal study

“…Finding relatively more males of C. schultzei gp. during the peak time may indicate on preferred swarming location of this species near the animal as was suggested for C. oxystoma in Senegal (Fall et al ., 2015).…”