University of Montana 



Agricultural Experiment Station 



BOZEMAN, MONTANA 



lUI.I.KTIN NO. 139 



lANfJARV, 1921 



Eighteenth Annual Report of the 



State Entomologist 



of Montana 



The Tliistle Butterfly (Vanessa cardiii L. ), a serious pest of cultivated sunflowers. 



BY 



R. A. COOLEY 



