Figure 1.

Climatic conditions recorded from 2008-2013 by a governmental weather station at Segou, Mali (13.45°N, 6.26°W), a village at the southern edge of the Sahel; north of this location, conditions are drier. The period defined as the wet season (June through mid-October) is shaded in light green throughout. A) Total monthly rainfall (in mm), shown as a box-whisker plot (box stretches from the 1^st to the 3^rd quartiles and whiskers extend to the extreme values up to 1.5 times the inter-quartile range). Mean monthly rainfall depicted with diamonds; mean annual rainfall is 570 mm with a range of 225-964 over the 5-year period. Dotted line marks 30 mm rain, representing the minimal single rain event providing enough water to keep some larval sites for the duration of complete development of the aquatic stages of Anopheles gambiae s.l. B) Daily maximum temperature (red; measured at 15:00), minimum temperature (dark blue; measured at 06:00), and dew point (light blue; measured at 06:00). Shaded bands represent the range between 1^st and 3^rd quartiles. C) Daily photoperiod, with the number of daylight hours (sunrise to sunset) shown.