Fig. 2

Timecourse of initial establishment (days 1–5) of midgut infection in teneral, non-teneral and sequentially-fed flies. Flies (Glossina morsitans morsitans) were fed on a bloodmeal containing F1R1 and F1G2 as tenerals, 18 day non-tenerals, or sequentially with the F1R1 infective feed 18 days after the first feed with F1G2. a Percent of midguts that were positive or negative for FIR1 trypanosomes upon dissection; all midguts were positive for F1G2. The sequentially fed flies had significantly more negative midguts than both teneral (Fisher’s exact test: P = 0.02) and non-teneral flies (Fisher’s exact test: P = 0.04) at day 5. N = number of flies. b Average counts (log ± se) of F1R1 trypanosomes per macerated positive midgut. Treatment had a significant effect on the number of trypanosomes in midguts (ANOVA: F _(2,77) = 25.15, P < 0.0001), with significantly lower numbers of trypanosomes in the positive midguts for the sequentially fed flies than either teneral (Post-hoc LSD test: P < 0.0001) or non-teneral flies (Post-hoc LSD test: P = 0.04), and significantly lower numbers for non-teneral than teneral flies (Post-hoc LSD test: P < 0.0001). N = number of flies; trypanosome negative flies have been excluded from the total