Longevity and Further Flight Range Studies on the Blackflies (Diptera, Simuliidae), with the use of Dye Markers 1

Abstract

In discussing the role of blackflies in the transmission of onchocerciasis in Guatemala, three important problems must be considered. First, it should be determined whether the flight range of the anthropophilic species is sufficient to permit the introduction and subsequent establishment of vector species into areas supposedly free of onchocerciasis; second, the length of life of the females should be known in order to correlate it with the first point, thereby giving additional weight to the possibility that the disease may extend beyond its present boundaries; and third, it must be determined whether or not infection with the immature stages of Onchocerca adversely affects the flight range and longevity of blackflies. If infection greatly reduces flight range and life span, this may explain the restriction of the disease to its presently known areas. From the standpoint of insecticidal control of the anthropophilic species of blackflies, the first two mentioned considerations would indicate to what extent infiltration by the flies from non-treated to treated areas might be expected. This information would serve in establishing the size of the area that must be treated in order to achieve adequate control.