Daily activity profile of L. longipalpis under 25°C, but combined with three distinct photoperiods. (A) Average locomotor activity over all sandflies submitted to two days of LD 08:16 (blue lines, n = 25), LD 12:12 (green lines, n = 22) and LD 16:08 (red lines, n = 29). The horizontal white bar indicates the light phase, while the black bar indicates the dark phase. ZT is the zeitgeber time within a light/dark cycle experiment; ZT 0 corresponds to the lights-on event and ZT 8 (LD 08:16), ZT 12 (LD 12:12) and ZT 16 (LD 16:08) depict the lights-off event of each photoperiod. (B) Mean ± SEM (vertical bars and lines, respectively) of individual anticipation index of L. longipalpis (see Methods) for each photoperiod condition. (C) Differences of dusk-related onset, maximum peak and offset of locomotor activity for each photoperiod condition. Mean ± SEM (vertical lines) and individual sandfly (circles) in Zeitgeber time (ZT). Lights on/off (‘dusk’) transitions are indicated by vertical dotted lines at 0 h relative to each photoperiod (ZT 08, ZT 12 and ZT 16, see Methods for further details). *p < 0.05; **p < 0.01; ***p < 0.001; one-way ANOVA and respectively post-hoc tests (see Table 2).