24 MONTANA EXPERIMENT STATION BULLETIN 366 



Bran 100 lbs. 



Water 12 gals. 



Cane molasses 8 qts. 



Sodium arsenite 4 lbs. 



Comparative tests were run to discover whether the ad- 

 dition of molasses was essential. Although the experi- 

 ments were insufficient to furnish definite conclusions, 

 the indications were that the addition of molasses was 

 desirable. 



2. Where irrigation water was available, a small stream of 

 water running through the ditches served as an excel- 

 lent barrier. 



3. Where water was not available, steep-sided ditches which 

 were kept dusty by dragging a log through them proved 

 good barriers, largely stopping migrations of worms. 



SAY'S PLANT BUG 



( Chlorochroa sayi Stal.) 



While not so abundant this past season as in some previous 

 years, this pest continued to injure wheat more or less in the 

 Triangle Area north of Great Falls. Information is not available 

 as to the total loss suffered in the State during the past bien- 

 nium. It was estimated that there was a 3 per cent injury to 

 wheat kernels on one farm near Big Sandy. Say's plant bugs were 

 extremely abundant at the North Montana Branch Experiment 

 Station at Havre the last week in July. An examination of range 

 areas was made in the vicinity of the Station at that time and 

 a few bugs were found in areas where the range was poor and 

 Russian thistles and tumbling mustard were invaders. They were 

 extremely rare in these situations, however. 



Say's plant bug is most abundant in the spring in weedy 

 fields where the nymphs feed to a large extent on the above 

 weeds. Later in the season they migrate into wheat fields. The 

 present infestation in Montana has just passed its sixth year and 

 shows little tendency to disappear — in fact, large populations 

 have been encountered as far east as Rosebud County and the 

 vicinity of Fallon in Prairie County. It may be that the continu- 

 ance of the pest in the State is in part at least the result of 

 large acreages of abandoned crop land. 



