Contribution to the distribution of Glossina (Diptera: Glossinidae) in Mali

Abstract

A ground survey to map the distribution of Glossina prior to the initiation of a control programme was undertaken in an area of more than 100 000 km 2 in the Sudan and Guinea savanna zones of Mali. The area extends from 1T13' to 14°15'N. and 5°53' to 10°24'W. The ChallierLaveissiere trap was the main survey tool, but other methods were used when the traps did not catch flies in areas suspected of being suitable for Glossina. The results are compared with existing distribution maps of the area, including one based solely on interpretations of earth satellite photography of the area. Infestation by G. morsitans submorsitans Newst. was continuous west of 8°20'W. and intermittent east of this. Apparent recent advances of G. m. submorsitans and G. palpalis gambiensis Vanderplank were noted, but G. tachinoides Westw. seemed to have receded. Possible reasons for these differences between species are discussed.

Distribution of Glossina (Diptera: Glossinidae) in Mali

“…Three of these, G. m. submorsitans, G. p. gambiensis and G. tachinoides, had been reported to infest relatively large areas in southern Mali, whereas the fourth species, G. longipalpis Wiedemann, had been reported only from a small zone along the border of Guinea just north of 12°N and just west of 11°W. The results of our survey work and that reported by Okiwelu et al (1981) confirmed the presence of only the three species previously reported as relatively widespread in southern Mali. However, the current distributions of all three of these species differ from those shown by Ford & Katondo (1973).…”

“…CVL/TAMU personnel surveyed areas outside those covered by the New Lands Activity except for vector monitoring necessitated by other research objectives at two locations and for three joint exercises carried out with New Lands personnel during the early months of field survey work. Okiwelu et al (1981) presented the results of the New Lands field survey, noting that the distributions of G. m. submorsitans and G. palpalis gambiensis Vanderplank had apparently increased while that of G. tachinoides Westwood had apparently decreased in comparison to that shown by Ford & Katondo (1973). However, CVL/ TAMU personnel had previously reported these changes at the 16th meeting of the International Scientific Council for Trypanosomiasis Research and Control, Yaounde, Cameroon, 29 October-3 November, 1979 (Ashton, et al, in press).…”

“…To facilitate comparison with pre-1977 information and to provide as complete a picture of the distribution of each species as possible, distribution maps accompanying the species discussions in the next section show the distribution as shown by Ford & Katondo (1973), the areas where the species was collected by the New Lands personnel as presented by Okiwelu et al (1981) and the areas where it was captured by CVL/TAMU personnel. The symbols used to reflect the last two categories denote areas of collection and not individual collection sites.…”

“…However, CVL/ TAMU personnel had previously reported these changes at the 16th meeting of the International Scientific Council for Trypanosomiasis Research and Control, Yaounde, Cameroon, 29 October-3 November, 1979 (Ashton, et al, in press). In addition to mentioning the changes in distribution, Okiwelu et al (1981) provided a map showing areas where each species had been captured and provided some comments on the possible reasons for the changes in overall distribution of each of the species.…”

“…The purpose of the present report is to present the results of the field survey work carried out by the CVL/TAMU personnel and to combine this information with that presented by Okiwelu et al (1981) and thereby provide the most complete representation possible of the current distribution of species of Glossina in Mali. The combined efforts of the two projects has resulted in more than 90% of the part of Mali thought capable of supporting tsetse populations being surveyed (Fig.…”