MONTANA INSECT PESTS, 1951-1952 25 



backrubber was set up near Cascade, Montana, in 1952. This par- 

 ticular test did not produce satisfactory horn fly. control. It is pos- 

 sible that more of the backrubbers were needed, or that the brush 

 in this particular range area competed with the backrubber so 

 that the cattle were rubbing on the brush far more frequently 

 than they were on the backrubber. This demonstrational test will 

 be pursued further in hopes of developing a satisfactory method 

 of this type under Montana conditions. 



The incidence of horn flies appeared to be about normal dur- 

 ing the biennium except that in 1952 the horn fly season was 

 somewhat longer than normal due to an abnormally warm fall 

 period. 



MISCELLANEOUS 



THE GOAT WEED BEETLE PROGRAM 



INITIAL INTRODUCTIONS 



Prior to 1951 several introductions of goatweed beetle colonies 

 had been made into western Montana principally through the 

 efforts of Mr. James K. Hollaway, Entomologist for the United 

 States Department of Agriculture, Bureau of Entomology and 

 Plant Quarantine. Of these several introductions, those that have 

 been kept under observation were a 1948 planting of Chrysolina 

 hyperici in the Charlos Heights area of Ravalli County and a 1949 

 planting of Chrysolina gemellata in the Charlos Heights area of 

 Ravalli County. Also 1949 plantings of Chrysolina hyperici in 

 Sanders County on the O. J. Murray Ranch, on the Forest Service 

 mule pasture just north of Thompson Falls, on the bison range, 

 and in Flathead County on the north fork of the Flathead River 

 were observed. 



Obeservations through the 1950 growing season yielded little 

 or no evidence which would indicate that these plantings would 

 establish themselves strongly enough to provide for redistribution 

 throughout western Montana and biological control of goatweeds. 



The above colonies were introduced under rather adverse 

 conditions. In each case several days had elapsed between the 

 time of collection in California and the time of release in Mon- 

 tana. Consequently, the beetle colonies were in a weakened state 

 at the time of introduction. 



1951 INTRODUCTION 



In the winter of 1950 the Western Montana Weed Control 

 Committee in surveying the goatweed problem found the follow- 

 ing estimated infestations: Missoula County, 1 acre; Lincoln 

 County, 40 acres; Flathead County, 60 acres; Mineral County, 420 



