10/20 : Attacked in hammocks by tiny gnat not over one tenth of an inch in length; mosquito nets no protection; gnats bite all night allowing no sleep.

10/21 : Another sleepless night on account of blood-sucking gnats.

10/22 : My body mass of bumps from insect bites, wrists and hands swollen from bites of tiny gnats. 2 nights with almost no sleep – simply terrible. Rain during noon, all afternoon and most of night. My shoes have been soaked since starting. Worst ticks so far.

10/23 : Horrible night with worst biting gnats yet; even smoke of no avail.

10/24: More than half ill from insects. Wrists and hands swollen. Paint limbs with iodine.

10/25 : Arose to find termites covering everything left on the ground. Blood-sucking gnats still with us.

10/30 : Sweat bees, gnats and “polverinahs” (blood-sucking gnats) terrible.

11/2 : My right eye is sadly blurred by gnats.

11/3 : Bees and gnats worse than ever; truly “there’s no rest for the weary”.

11/5 : My first experience with flesh- and carrion-eating bees. Biting gnats in clouds – very worst we have encountered – rendering one’s food unpalatable by filling it with their filthy bodies, their bellies red and disgustingly distended with one’s own blood.

from the 1920 Amazonian expedition diary of Ernest Holt, quoted in The Lost City Of Z by David Grann (2009)