Weevil monitoring 



A comparison of 1993 weevil monitoring impact with previous 

 year's monitoring by the U.S. Forest Service (Field and Lovelace 

 1991, Phillips 1992) documented an apparent localized eradication 

 of Rhinocyllus conicus from the Kings Hills #2 sample area 

 between 1992-1993 (Tables 3 and 4) . The 1992 growing season 

 ended early with a heavy Little Belt Mountains snowstorm on 23 

 August, and it the weevil may not have had time to complete its 

 life cycle at the high elevation site represented by Kings Hill. 

 The weevil reguires 39-62 days after eggs are laid on the bolting 

 plants for hatching of eggs, feeding, and pupal stage development 

 prior to emergence of adults (Rees 1982) . It is not known where 

 they overwinter. 



Alternatively, weevil numbers may have plummeted in the wake of 

 two consecutive low-flowering years. This is supported by the 

 marked difference in infestation levels in population segments of 

 different density (see paired Russian Creek sample results, 

 Tables 3 and 4) . Even at sites that had nearly all plants 

 infested in 1993 (Russian Creek, Duck Creek Pass) , over half of 

 the flowers lacked infestation. 



Table 3. Weevil infestation among all flowers 



13 



