Table 4. Weevil infestation intensity per infested flower 



Infestation was consistently most intense on the terminal 

 (oldest) flower heads. 



Weevil invasion in 1993 was localized among the monitored Cirsium 

 longistvlum sites (Table 5) . The three sites with heavy invasion 

 are the farthest removed from one another. Under continuous host 

 availability, Rhinocyllus conicus might be expected to expand its 

 range 5-15 miles per year (Rees pers. commun.). It is noted that 

 two of the three infestation sites are close to major U.S. Forest 

 Service road thoroughfares (Duck Creek Pass, Russian Creek) . 



Table 5. Weevil infestation on 

 flowering plants per plot 



Heaviest infestation levels are in populations with opposite 

 bract character profiles (Table 5) . If bract character is a 

 valid indication of taxonomic status and hybridization, then 

 preliminary evidence indicates that the weevil does not show a 



14 



