Studies on the transmission of the virus of little cherry disease in the Kootenay Valley of British Columbia involve the feeding of introduced insects on uninfected cherry trees. Muslin cages slipped over individual branches and tied at both ends were first used to confine the introduced insects but resulted in heavy insect losses. Temperature within the caged area was likely to be excessive, it was difficult to introduce and recover the insects, and insects became entangled in the muslin. A special cage has been designed to overcome these difficulties.