14 MONTANA EXPERIMENT STATION BULLETIN 504 



PLUM NURSERY MITE (Vasates fockeui) 



and 



BIG-BEAKED PLUM MITE (Diptacus gigantorhynchus) 



Populations of these mites were below economic importance in 1953. 

 However, in 1954 a general outbreak occurred on the east shore of Flathead 

 Lake and had to be brought under control by the use of miticides. 



PEAR SLUG (Caliroa cerasi) 



During 1953 one economic infestation on cherry trees was reported 

 from Mineral Count\^ During 1954 economic infestations occurred in 

 Broadwater, Gallatin, Lake, and Ravalli counties. 



BLACK CHERRY APHID (Myzus cerasi) 



Although populations of this pest were normal or below during 1953, 

 there was an increase in numbers during 1954. Delayed dormant oils 

 applied in late spring control this pest very well. 



CODLING MOTH (Carpocapsa pomonella) 



No unusual outbreaks of this insect occurred during 1953. In 1954 

 one infestation in an apple orchard in Carbon County was reported. This 

 pest is usually not dangerous where spray schedules in commercial plant- 

 ings are followed closely. 



PEAR LEAF BLISTER MITE (Eriophyes pyn) 



Where orchards received preventative spray treatment this pest has 

 not become abundant. However, it does continue to seriously infest most 

 western Montana orchards that do not receive treatment. In 1954 it was 

 reported from Lake, Ravalli, Missoula, and Flathead counties. 



SMALL FRUITS 



CURRANT FRUIT FLY (Epochra canadensis) 



Although the currant fruit fly is wide!}' distributed throughout the state, 

 it was reported only from Sweet Grass County in 1953. There were no 

 economic infestations reported or observed in 1954. 



RASPBERRY CANE BORER (Oberea bimaculata) 



Light to moderate infestations occuned generally throughout western 

 Montana during the biennium. 



RASPBERRY ROOT BORER (Bembecia marginata) 

 Severe infestations occurred throughout many areas of western Montana. 



