An Adjustable High-Definition Imaging System for Behavioral Studies of Drosophila Adults

Drosophila melanogaster is a very powerful model in biological research, but a bad model for photography or videography. This paper describes a simple but effective method to observe and document the behavior or morphology of flies. Flies were placed in a translucent observation chamber c.a. Ø15 x 5mm (no food inside) or Ø15 x 12 mm (with an 8 mm-high piece of food inside). After covering with an ultraviolet (UV)/clear filter with high light transmittance, the chamber was placed under a 5-50x zoom stereo microscope, and mini light-emitting diode (LED) video lights were placed on both sides of the microscope to illuminate the chamber to obtain uniform, soft, bright, and nearly shadow-free light. Then, a compact digital camera with 3-5x optical zoom, which can record 1080 P high-definition or higher resolution video (at a frame rate of ≥30 fps), was connected to the eyepiece of microscope through a bracket, and photographs or videos were taken through the eyepiece. By adjusting the zoom knob of the zoom stereo microscope, it was very easy to track the flies and take panoramic or detailed close-up images as needed, while the camera recorded everything under the microscope. Because the flies can stay at any position in the chamber, they can be observed and recorded from all directions. The photographs or videos taken are of good image quality. This method can be used both for scientific research and teaching.