collection of dauer stages

[James Campbell]

I am a graduate student at UCD and am interested in comparing the 
behavior of a wide range of rhabditid nematodes - both freeliving and 
insect parasitic.  I was interested in finding out if anyone knew of a 
way to collect relatively pure populations of dauers from cultures on 
agar plates.  A technique that would be useful for a wide range of 
species would be best.  Thanks for your help