a. Large (30 × 30 × 30 cm) fabric-net adult holding cage suspended on a metal frame (Photo by T. Spitzova); b. Custom-made polycarbonate adult holding cage (30 × 30 × 30 cm) with a paper-insert resting surface on the back panel used for holding live flies in the field and during transport. A piece of sugar-soaked cotton is placed on the screen top as an energy source for the flies (Photo by E. Rowton).