Granary Weevil
Sitophilus zeamais?
Observed near Kaptumo, Kenya, April 2013. Length is about 4mm. The insect was on the wing before alighting on this leaf.
From Wikipedia: A close relative of the rice weevil, the maize weevil has a length of 2.5 mm to 4 mm. This small, brown weevil has four reddish-brown spots on the wing covers (elytra). It has a long, thin snout, and elbowed antennae. Sitophilus zeamais appears similar to the rice weevil (Sitophilus oryzae), but has more clearly marked spots on the wing covers, and is somewhat larger. It is able to fly.