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The Schultzei group of Culicoides Latreille (Diptera: Ceratopogonidae) is distributed throughout Africa to northern Asia and Australasia and includes several potential vector species of livestock pathogens. The taxonomy of the species belonging to this species group is confounded by the wide geographical distribution and morphological variation exhibited by many species. In this work, morphological and molecular approaches were combined to assess the taxonomic validity of the species and morphological variants of the Schultzei group found in Senegal by comparing their genetic diversity with that of specimens from other geographical regions. The species list for Senegal was updated with four species: Culicoides kingi, C. oxystoma, C. enderleini and C. nevilli being recorded. This is the first record of C. oxystoma from Africa south of Sahara, and its genetic relationship with samples from Israel, Japan and Australia is presented. This work provides a basis for ecological studies of the seasonal and spatial dynamics of species of this species group that will contribute to better understanding of the epidemiology of the viruses they transmit. [ABSTRACT FROM AUTHOR]

The Schultzei group of Culicoides Latreille (Diptera: Ceratopogonidae) is distributed throughout Africa to northern Asia and Australasia and includes several potential vector species of livestock pathogens. The taxonomy of the species belonging to this species group is confounded by the wide geographical distribution and morphological variation exhibited by many species. In this work, morphological and molecular approaches were combined to assess the taxonomic validity of the species and morphological variants of the Schultzei group found in Senegal by comparing their genetic diversity with that of specimens from other geographical regions. The species list for Senegal was updated with four species: Culicoides kingi, C. oxystoma, C. enderleini and C. nevilli being recorded. This is the first record of C. oxystoma from Africa south of Sahara, and its genetic relationship with samples from Israel, Japan and Australia is presented. This work provides a basis for ecological studies of the seasonal and spatial dynamics of species of this species group that will contribute to better understanding of the epidemiology of the viruses they transmit.

Feeding success of free-living hematophagous insects depends on their ability to be active when hosts are available and to reach places where hosts are accessible. When the hematophagous insect is a vector of pathogens, determining the components of host-seeking behavior is of primary interest for the assessment of transmission risk. Our aim was to describe endo/exophagy and circadian host-seeking activity of Palaearctic Culicoides species, which are major biting pests and arbovirus vectors, using drop traps and suction traps baited with four sheep, as bluetongue virus hosts. Collections were carried out in the field, a largely-open stable and an enclosed stable during six collection periods of 24 hours in April/May, in late June and in September/October 2010 in western France. A total of 986 Culicoides belonging to 13 species, mainly C. brunnicans and C. obsoletus, was collected on animal baits. Culicoides brunnicans was clearly exophagic, whereas C. obsoletus was able to enter stables. Culicoides brunnicans exhibited a bimodal pattern of host-seeking activity with peaks just after sunrise and sunset. Culicoides obsoletus was active before sunset in spring and autumn and after sunset in summer, thus illustrating influence of other parameters than light, especially temperature. Description of host-seeking behaviors allowed us to discuss control strategies for transmission of Culicoides-borne pathogens, such as bluetongue virus. However, practical vector-control recommendations are difficult to provide because of the variation in the degree of endophagy and time of host-seeking activity.