18 MONTANA EXPERIMENT STATION BULLETIN 526 



SAN JOSE SCALE (Aspidiotus perniciosus) 



Only one report of this insect was recorded during the biennium 

 —from Lake County in 1955 where it occurred on willow. 



SPRING CANKERWORM (Paleacrita vernata) 



A rather widespread outbreak of this shelterbelt defoliator occurred 

 from the central part of the state to the eastern border during 1955. 

 No cases were reported in 1956. 



A TENT CATERPILLAR (Malacosoma leutescens) 



This close relative of the forest tent caterpillar defoliated elms in 

 Prairie County in 1956. 



VAGABOND GALL (Mordwilkoja vagabunda) 



Infestations of these aphids appear to be down this biennium. 

 However, the northeastern corner of the state had large local popu- 

 lations. 



VIRGINIA CREEPER LEAF HOPPER (Erythroneura ziczac) 



This pest was present in large numbers during 1955 in the central 

 and Triangle areas of the state. No reported infestations occurred in 

 1956. 



Coniferous Ornamentals 



BLUE SPRUCE GALL APHID (Adelges cooleyi) 



During the biennium this perpetual pest continued to cause con- 

 cern in the area east of the mountains. Trees are not injured but 

 made unsightly by the cone-like galls on the tips of the new growth. 



A JUNIPER BORER (Phloeosinus dentatus) 



This small snout beetle was reported for the first time in the 

 state from Powder River County. It bores into the bases of juniper 

 twigs causing death of the terminal parts. 



PINE LEAF SCALE (Phenacaspis pinifoliae) 



Pine leaf scale on spruce was uncommon in 1955, but it was very 

 abundant in the Triangle Area and in spots west of the mountains in 

 1956. 



