TWENTY-EIGHTH REPORT OF THE STATE ENTOMOLOGIST 19 



It is likely that this insect does not at present exist in the 

 State. Any of the symptoms mentioned above occurring on pears 

 should be reported and specimens sent immediately to the State 

 Entomologist, Bozeman, Montana. 



Lettuce Root Aphis. — During the first week in August 1940, 

 a report was received of injury being suffered by a large plant- 

 ing of head lettuce in the Gallatin Canyon. An examination of 

 the field revealed a large population of root lice attacking pri- 

 marily the second planting. This insect was identified through 

 the kindness of Miss M. A. Palmer as Pemphigus bursarius Lin- 

 naeus. The planting most heavily attacked was practically a 

 complete loss; the rest of the field was heavily irrigated for some 

 time after the discovery of the insects, and, although they were 

 present on the last two cuttings, the damage noticed was small. 



Spruce Gall Lice. — Cooley's spruce gall louse (Adelges cool- 

 eyi Gill.) is abundant throughout the State both on native and 

 ornamental trees. There seems to be an individual susceptibility 

 in stands of Engelmann spruce (Picea engelmanni) , some trees 

 being heavily infested, and others close by practically immune. 

 It has been noted further that black hill spruce (Picea glauca al- 

 bertiana) and Norway spruce (Picea excelsa) are more heavily 

 infested than native forms. Another spruce gall aphis (Pineus 

 pinijoliae (Fitch)) was found attacking Engelmann spruce 

 at the head of Squaw Creek, Gallatin County, June 26, 1940, at an 

 elevation of approximately 9000 feet. The terminal gall caused 

 by this insect differs from the gall of Cooley's spruce gall louse 

 in being composed of flat scales, giving it a cone-like appearance. 

 (See figure 5). This species has not as yet been recorded as 

 damaging ornamentals in the State. 



Although research on the control of the spruce gall louse in 

 Montana is not complete, good control has been obtained in other 

 parts of the country. A spray consisting of one quart of 40 per 

 cent nicotine sulphate and five gallons of miscible oil to 200 gal- 

 lons of water has been found to be satisfactory. The spray is 

 applied in the spring when the young are hatching from the 

 cotton-covered egg masses and colonizing the new growth. 



Striped Cucumber Beetle. — This pest of cucurbits (Diabroti- 

 ca vittata (Fabr.)) was neither reported nor collected in 1939, 

 although in 1938 distribution included Daniels, Roosevelt, and Yel- 



