MONTANA INSECT PESTS, 1951-1952 7 



Seed treatment applying one ounce of lindane per acre to 

 spring seeded wheat has proved to be an effective control. In ad- 

 dition, recently completed tests indicate that the same treatment 

 is also effective on fall seeded winter wheat. 



BLISTER BEETLES (Meloidae family) 

 Scattered cases of damage to sugar beets, alfalfa, gardens, and 

 ornamental shrubbery occurred in many parts of eastern Mon- 

 tana during 1951. No field crop damage and very little garden or 

 ornamental damage by blister beetles was reported in 1952. DDT 

 spray application appears to be controlling the blister beetles un- 

 der all circumstances of occurrences. 



FLEA BEETLES (Epitrix sp. and Systena sp.) 

 Severe infestations of the potato flea beetle Epitrix sp. oc- 

 curred in the spring of 1951 on seedling sugar beets in Blaine, 

 Phillips, Richland, Dawson, Prairie, Rosebud, Custer, Treasure, 

 Big Horn, and Yellowstone counties. The application of 12 to 15 

 pounds of 5 percent DDT dust per acre resulted in erratic control. 

 Where 5 percent DDT dust was used at 20 pounds per acre, eco- 

 nomic control was more consistent. In 1952 severe damage to 

 seedling sugar beets occurred in Richland County with less severe 

 damage occurring in Blaine, Prairie, Rosebud, and Carbon coun- 

 ties. Five percent DDT dust applied at the rate of 20 pounds per 

 acre was used in Richland County in 1952 with consistently good 

 results. 



The banded flea beetle, Systena sp., was not reported in eco- 

 nomic numbers in 1951. In 1952 unusually large populations of 

 banded flea beetles occurred during June and early July in many 

 alfalfa fields of southcentral and southeastern Montana. Numer- 

 ous cases of the flea beetles causing serious defoliation were ob- 

 served. 



THISTLE BUTTERFLY CATERPILLARS (Vanessa cardui) 

 This insect did not occur in appreciably large numbers in 

 1951. In early June of 1952 many large flights of painted lady 

 butterflies were observed over various parts of the western three- 

 quarters of Montana. By late June, the caterpillars or larval form 

 of this insect were abundant in many localities. Larval feeding 

 was largely confined to various species of thistles; however, re- 

 ports were received of severe damage to beans, potatoes, clover, 

 corn, cabbage, and hollyhocks. Toxaphene sprays were success- 

 fully used for control. 



FIELD CRICKETS (Acheta assimilis) 



Occasional cases of field crickets damaging alfalfa seed in the 

 shock occurred during the biennium in northeastern Montana. In 



