Food preference in Drosophila robusta and Drosophila tripunctata following desiccation

Drosophila tripunctata and Drosophila robusta are local species trapped on the University of Northern Iowa preserve off of University Avenue. Drosophila literally means lover of dew . Tripunctata means three points , it has 3 points on its abdomen. Robusta means robust , of which this species definitely is. D. tripunctata are a small species, which leaves them with a low volume/surface area ratio. This means they are more susceptible to environmental extremes, particularly the loss of water. D. robusta are a large and robust fly, and they are more tolerant of such environmental hardships. Desiccation is drying out, or to remove moisture. This is done with flies by removing food, which is also their source of water. Food also is the site of egg laying for females, and may provide an alternative attraction to a specific bait