8 MONTANA EXPERIMENT STATION BULLETIN 504 



RED-BACKED CUTWORMS (Eaxoa ochrogaster) 



Several severe infestations occurred in western Montana in 1953. Most 

 of these infestations were confined to gardens and truck crops. Only light 

 infestations occurred in the same general area in 1954. 



BLISTER BEETLES (Family: Mcloidac) 



Blister beetles are apparently becoming more important in the eastern 

 part of the state. In 1953 blister beetles attacked potato fields and caragana 

 hedges in Dawson County. In 1954 Nuttall's blister beetle (Lytta nuttalU) 

 was present in large numbers in Dawson, Wibaux, and Richland counties 

 in small grains, gardens, and in alfalfa. 



CRESTED WHEAT PLANT BUGS (Labops hesperius) 



Damaging populations occuned in several crested wheatgrass fields 

 in Cascade County in 1953. There was little damage from this insect in 

 1954, and only one light infestation was reported from Chouteau County. 



FLEA BEETLES (Epitrix sp. and Systena sp.) 



Several seedling sugar beet fields in Richland County were seriously 

 damaged in 1953 and 1954. Economic populations occurred on potatoes 

 in Gallatin Count\^ in 1953. 



WESTERN CHINCH BUGS (Blissus — new species near occiduus) 



In 1953 two single, localized infestations occurred: one confined to 

 crested wheatgrass in Big Horn County; the other involving adjacent areas 

 of crested wheatgrass, barley, oats, and sj^ring wheat in Beaverhead County. 

 The damage in both cases was severe. This insect was also observed in 

 native range, primarily on Stipa comata and Agropyron smithii, where it 

 caused no apparent damage. It was not reported in 1954. 



WHITE GRUBS (Phyllophaga sp.) 



A single economic infestation occurred in a potato field in Cascade 

 County in 1953. In 1954 these insects were found to be very abundant 

 in a winter wheat field in Gallatin County; however, no apparent damage 

 resulted. 



INSECTS DESTRUCTIVE TO FIELD CROPS 



SMALL GRAINS 



WHEAT STREAK MOSAIC 



In 1954 many of the wheat fields in north-central and eastern Montana 

 exhibited a yellowish and unhealthy appearance early in the spring. On 

 examination these plants proved to be infested with thrips and vidth a mite. 

 The thrips later were proven to be of little consequence in producing the 



