Design of test chambers and oviposition attractants used in this study.

In paired-choice bioassays we placed a pair of small (125 ml), round, transparent jars in opposite sides of the cage (A). When testing for attraction of flies to visual or olfactory cues, we used sticky screen jars comprising a sand cup (a 30 ml disposable plastic cup containing 10 ml of wet autoclaved sand) with a sticky screen placed on top of it (B). When testing the effect of visual oviposition cues, we wrapped the treatment jar with either black or white poster papers and left the unwrapped jar as control (A, C). Bioassays evaluating the effect of sand fly sex or stage on their visual oviposition response were conducted using black and white jars (D). When testing for olfactory oviposition cues, we placed 0.1 g of larval frass in treatment jars (B) with no frass in the control jars. White filter paper was placed loosely above the sand (B) to control for possible visual effects. Image Credit: Daniel J. Smith.