The African Chrysops

Abstract

African Chrysops are less studied than their European and American counterparts. The bionomics of only Chrysops silacea and Chrysops dimidiata is frequently reported. These two species feed on mammals in general but humans remain their main host. From the resting place in the canopy of the natural and secondary forest, they locate their hosts as they move but smoke of wood is a much better attractant than the movement. Other species live either in the rain forest or in the wooden savannah feeding on mammals and reptiles. Chrysops are biological and mechanical vectors of diseases in human and livestock. They also cause painful bites often resulting in open wounds, which can serve as open door for bacterial infections. In the past, control relied on the use of insecticides and clearing of vegetation around the habitations. Nowadays, recourse to repellents, trappings and destruction of the canopy around houses is recommended. The detailed geographical distribution of African Chrysops is still to be elucidated, as well as any genetic variability within and among species. The aims of the chapter are to provide the reader with the state-of-the-art knowledge on African Chrysops, and to present the gap in knowledge of this genus species.

A Nationwide Survey of Tabanidae Fauna of Cameroon

“…A review on the genus Chrysops of Africa with focus on Cameroon [14] mentioned only the occurrence of C. silacea and C. dimidiata, whereas our survey reveals 5 species, notably C. distinctipennis, C. longicornis, C. funebris, C. silacea and C. dimidiata. The possible reason for the previous scanty record of the species of this genus [14] could be because the earlier entomological surveys were limited to the forest regions of Cameroon, where C. silacea and C. dimidiata are omnipresent. Interestingly, the 1955 report on the presence of 5 species of Chrysops [15], notably C. dimidiata van der Wulp, C. Silacea Austen, C. funebris Austen, C. longicornis Macquart and C. stigmaticalis Loew was conducted in the same study areas as those in the review on the genus Chrysops [14].…”

“…The newly identi ed tabanid species of Cameroon all existed in the list of Tabanidae from neighboring countries of the Central and West African sub-regions [11,12,19,25,40]. A review on the genus Chrysops of Africa with focus on Cameroon [14] mentioned only the occurrence of C. silacea and C. dimidiata, whereas our survey reveals 5 species, notably C. distinctipennis, C. longicornis, C. funebris, C. silacea and C. dimidiata. The possible reason for the previous scanty record of the species of this genus [14] could be because the earlier entomological surveys were limited to the forest regions of Cameroon, where C. silacea and C. dimidiata are omnipresent.…”

“…The possible reason for the previous scanty record of the species of this genus [14] could be because the earlier entomological surveys were limited to the forest regions of Cameroon, where C. silacea and C. dimidiata are omnipresent. Interestingly, the 1955 report on the presence of 5 species of Chrysops [15], notably C. dimidiata van der Wulp, C. Silacea Austen, C. funebris Austen, C. longicornis Macquart and C. stigmaticalis Loew was conducted in the same study areas as those in the review on the genus Chrysops [14]. However, neither of these reports identi ed C. distinctipennis, a species recorded in the Guinean savanna ecozones of Cameroon in our current study.…”

“…The major blood-meal host of tabanids consist of humans, ruminants and wild animals [4,8]. The consequence of their blood feeding trait is the mechanical transmission of one of the most important cattle disease in Sub-Saharan Africa (SSA), African Animal Trypanosomiasis (AAT) [2,4,[9][10][11][12], in addition to the biological transmission of Loa loa lariasis [13,14]. The importance of studying the Tabanidae in relation to the mechanical transmission of pathogenic trypanosomes was emphasised at the 1948 African Conference on Tsetse and Trypanosomiasis in Brazzaville [15].…”

Evaluating the morphological and molecular challenges in identifying the afrotropical Atylotus species (Diptera: Tabanidae)

“…There are approximately 35 genera and 800 species of Tabanidae in the Afrotropical region that are found in forest, savanna, montane, coastal and desert biomes (Chainey, 2017). Tabanidae in Africa have been largely neglected in the past 50 years with the number of studies slowly increasing in recent years Dia, 2003, 2004;Ježek et al, 2019;Keita et al, 2020;Kouam and Kamgno, 2016;Lydie et al, 2017;Morita, 2008;Mugasa et al, 2018;Sasaki, 2005;Snyman et al, 2020;Taioe et al, 2017;Votýpka et al, 2015Votýpka et al, , 2019. Tabanids are known vectors of pathogens including viruses, bacteria, protozoans and filarial nematodes (Baldacchino et al, 2014).…”