For agile fliers such as Psephenus and Lutrochus on rocks protruding 

 from rapids or riffles, a net or plastic bag may be useful for catching 

 the specimens that tumble onto the water to be swept downstream briefly 

 before taking flight, but many specimens can be taken by aspirator or by 

 hand (it is best to wet your fingers first) . Approach the beetle care- 

 fully, without sudden movements, and pin it down lightly with a fore- 

 finger. The thumb and middle finger can then be used to grasp it. 



Sweeping foliage of trees and shrubs near streams may yield adults of 

 the Eubriinae, Chelonariidae, and Ptilodactylidae. This is not very 

 efficient, but no better method is known for collecting some of these. 



