8 MONTANA EXPERIMENT STATION BULLETIN 526 



deep seed planting was practiced, seedling damage was very high 

 during May and June since the false wireworms did most of then- 

 feeding at the ground level. The fact that they fed at least 3-4 inches 

 from die treated seed resulted in the insecticides having very little 

 effect on them. 



In 1956 the reduction of false wireworms, combined with the 

 more usual moisture conditions, resulted in a marked decrease of this 

 pest in the Triangle Area. However, occasional spotted damage con- 

 tinued to occur in eastern Montana. True wireworms were either not 

 as common in 1955 or else their depredations were masked by the 

 high population of false wireworms. In 1956 more true wireworm 

 damage occurred in spotted infestations throughout the wheat area 

 and in southern mountain valleys. 



A MIRID (Stenodema species) 



Although we are aware that many of these grass-feeding bugs 

 do damage to our forage crops, the first real evidence of extensive 

 feeding was found on tall wheat grass in Flathead County in 1956. 

 In addition, a crested wheat grass field in Yellowstone County was 

 also attacked. Damage by this insect very closely resembles that of 

 the crested wheat plant bug. 



EARWIGS (Forficula auricularia) 



During 1955 earwigs were very abundant on many garden crops 

 (especially sweet corn) and on ornamentals in the southwestern and 

 western part of the state. During 1956 very few inquiries concerning 

 this pest were received, but indications are that new areas are con- 

 tinually being infested. At the present time all of the area west of 

 the mountains and the area east of the mountains from Helena to 

 Lewistown and south to Park County is infested. 



CRESTED WHEAT PLANT BUG (Labops hesperius) 



In 1955 infestations occurred in Yellowstone County on barley and 

 in Lewis and Clark and Garfield counties on crested wheat. In 1956 

 McCone County had a local severe infestation on wheat and Judith 

 Basin County an infestation on crested wheat grass. 



INSECT PESTS IN FIELD CROPS 



Small Grains 



CORN LEAF APHID (Rhopalosiphum maidis) 



One of the most spectacular insect outbreaks in years involved 

 this insect when it appeared on barley in July of 1955. States farther 



