MONTANA INSECT PESTS, 1955-1956 17 



A LECANIUM-TYPE SCALE (Homoptera: Coccidae) 



During 1955 elm trees in Dawson County were infested. By 1956 

 infestations on sand cherry, rose, caragana, and other deciduous trees 

 were reported from eastern and northern Montana. 



LILAC BORER (Podosesia syringae) 



This insect was not recorded for 1956, but infestations occurred 

 in both lilac and ash in Valley and Rosebud counties in 1955. 



MOURNING CLOAK BUTTERFLY (Nijmphalis antiopa) 



This widely distributed pest was present in Liberty County in 

 1956 where its larvae were defoliating cottonwood trees. 



NEVADA BUCK MOTH (Hemileuca nevadensis) 



This insect was reported from Glacier and Judith Basin counties 

 in 1955 where it was defoliating willow. No reports of activity were 

 received in 1956. 



POPLAR BORER (Saperda calcerata) 



Only two cases of this wood-boring insect were reported during 

 the biennium: one from Cascade County and one from Glacier County. 



ROSE CURCULIO (Rhynchites bicolor) 



The rose curculio is generally present over the entire state and 

 control is a yearly necessity since tame roses are readily infested from 

 wild rose sources. Scattered light damage is present over most of 

 the state east of the divide. Local severe infestations occurred in Roose- 

 velt and Stillwater counties. 



ROSE GALLS (Diplolepis sp.j 



At least two species of Diplolepis have been responsible for rose stem 

 galls in the state. 1956 brought inquiries from many places in central 

 and eastern Montana regarding this pest. One type of gall is J2-I inch 

 in diameter and spinose; the other is 1-1/2 inches in diameter and 

 smooth. Picking the galls and burning them to prohibit further in- 

 festation is the only known control. 



ROSE SLUG (Hymenoptera: Tenthredinidae) 



Rose slugs were recorded from Hill County during 1955 and 

 from Lake and Stillwater counties in 1956. 



