Floatation method for the collection of Bradysia larvae. (A) A 2 L wide-mouth Erlenmeyer flask inverted on a graduated cylinder and containing fungus gnat larvae and larval culture substrate suspended in tap water. The larvae were collected at the bottom of the cylinder while most of the culture substrate remained floating in the flask. (B) Instars of Bradysia larvae collected by this method. Numbers indicate the different instars. Scale bar: 1 mm.