Foraging range of arthropods with veterinary interest: New insights for Afrotropical Culicoides biting midges (Diptera: Ceratopogonidae) using the ring method

Abstract

The identification of blood meal source of arthropod vector species contributes to the understanding of host-vector-pathogen interactions. The aim of the current work was to identify blood meal source in Culicoides biting midge species, biological vectors of internationally important arboviruses of livestock and equids, using a new ecological approach. We examined the correlation between blood meal source identified in engorged Culicoides females collected in a suction light trap and the available vertebrate hosts along four rings (200, 500, 1000 and 2000 m) centered at the trap site and described the foraging range of the three main vector species of veterinary interest present in the study area, Culicoides imicola, Culicoides kingi and Culicoides oxystoma. The study was performed in four sites localized in the Niayes region of Senegal (West Africa) where recent outbreaks of African horse sickness occurred. Blood meal source identification was carried out by species-specific multiplex PCRs with genomic DNA extracted from the abdomen of engorged females collected during nine night collections for twenty-six collections. The four most abundant hosts present in the studied area (horse, cattle, goat and sheep) were surveyed in each ring zone. The blood meal source varied according to Culicoides species and host availability in each site. C. oxystoma and C. imicola females mainly fed on horses readily available at 200 m maximum from the trap location whereas females of C. kingi fed mainly on cattle, at variable distances from the traps (200 to 2000 m). C. oxystoma may also feed on other vertebrates. We discuss the results in relation with the transmission of Culicoides-borne arboviruses and the species dispersion capacities.

Insight on the larval habitat of Afrotropical Culicoides Latreille (Diptera: Ceratopogonidae) in the Niayes area of Senegal, West Africa

“…No species-specific habitats were identified although C. kingi was particularly abundant in lake edge habitats in horse farms of Mbao and Niague; just one individual emerged from puddle edge in horse farm of Pout. Since the last outbreak of AHSV in 2007 in Senegal, several studies have been conducted in the same horse farms in the Niayes area to characterize Culicoides species diversity [21, 41, 42], trophic behaviour [42, 49–51] and population dynamics [21, 22] at the adult stage. These surveys conducted on adult populations in these three horse farms using suction black-light traps revealed a high species diversity with at least 18 species collected [21, 42], whereas 10 species emerged from the collected substrates in our study.…”

First molecular identification of the vertebrate hosts ofCulicoides imicolainEurope and a review of its blood‐feeding patterns worldwide: implications for the transmission of bluetongue disease andAfrican horse sickness

“…In the case of C. imicola, animals found within 200 m of traps were the most common sources of bloodmeals for midges (Bakhoum et al, 2016), which may explain why the present study failed to identify any wild species as a host of C. imicola in the study area. Wild ruminants are considered to represent common hosts of C. imicola in southern Spain in view of the relatively high prevalence of C. imicola-borne pathogens in these vertebrate species (Ruiz-Fons et al, 2014).…”

“…Species of the subgenus Avaritia, which includes the BT vectors C. imicola and C. obsoletus, use mammals as their preferred hosts, although the host species used and the frequencies of their use vary among studies (Table 2) (Martínez-de la . For instance, in Senegal, most C. imicola were found to feed on horses, but a percentage of the identified midges also fed on cows (Bakhoum et al, 2016). By contrast, humans were by far the most common hosts of C. imicola in Tunisia, although midges of this species also fed on goats, sheep, dogs and a single bird species (Slama et al, 2015).…”

“…Despite their importance in pathogen amplification, very little is known about the vertebrate hosts of C. imicola in Europe (Martínez‐de la Puente et al ., ; Ruiz‐Fons et al ., ). To the present authors' knowledge, extensive molecular studies have been conducted only in Africa, specifically in Tunisia, where C. imicola feeds mainly on humans [93% of 96 bloodmeals identified based on the amplification of the cythocrome b (cyt b ) and PNOC genes (Slama et al ., )] and in Senegal, where 96% of 26 identified bloodmeals derived from horses [based on cyt b amplifications (Bakhoum et al ., )].…”

Feeding behavior of Aedes (Aedimorphus) vexans arabiensis, a Rift valley fever virus vector in the Ferlo pastoral ecosystem of Senegal

“…Earlier investigations had used immunological assays [13, 19, 23] that have several inherent problems such as efficacy and reliability of blood meal identification [22, 24]. PCR based assays using different genetic markers have been developed for vectors targeting potential hosts for malaria, West Nile (WN) fever, African Horse Sickness or bluetongue research purposes (pig, human, goat, dog, cow; and avian) [17, 25–27]. PCR-based technology using host mitochondrial DNA provides a more direct approach to the identification of host species and increases sensitivity and specificity [22].…”