32 



NF.W ^■()RK STATl': INirSI-U'M 



The character of the soil, drainage, fertihty and tilth, the variety 

 of wheat and the time of sowing all modify injury by this tiny 

 midge with its remarkable adaptability. 



The truth of the above was abundantly evident during the ex- 

 tremely severe outbreak of 1901 and the less extended damage of the 

 past season. The wet spring of 191 2 resulted in succulent growth 

 most favorable for the development of maggots. To make matters 

 worse, dry weather at the time the preceding crop was harvested, 

 promoted shelling and subsequent moisture resulted in abundant 

 volunteer wheat and a resultant large fall brood of flies, the descend- 

 ants of these causing most of the injury in 191 2. 



Signs of infestation. The first indication of attack is found in 

 the darker color of the leaves and a tendency among the young 

 plants to stool freely. The broader lower leaves and the absence 

 of a central shoot, it having been killed, are also characteristic of 

 infested fields. As the attack advances the affected plants turn 



yellow or brown and die, and the 

 maggots may be found at the 

 base of the leaves near the 

 ground. The spring brood at- 

 tacks tillers or laterals which 

 were unharmed in the autumn, 

 dwarfing and weakening the stem 

 so that the grain usually lodges 

 before ripening or else fails to 

 develop fully. 



Causes of the outbreak. Ex- 

 treme dryness at the time of the 

 wheat harvest in 191 1 promoted 

 shelling and resulted in an un- 

 usually large crop of volunteer 

 wheat, which latter was greatly 

 favored by late summer rains. 

 Reference to the weather reports 

 Fig. I Base of infested wheat stem of this locality shows that in July 

 showing " flax-seeds " or piiparia nn- j^jj l^ j^^y ^^g favored with 



dcr the leaf sheaths (original) • •, ,• ,• _ ,_ 



^ ^ ^ a precipitation amounting to 



2.86 inches, most of this occurring between the 15th and the 



25th. There was an additional precipitation of nearly an inch 



in early August, followed by almost three-fourths of an inch 



in mid-August and nearly two inches the latter part of that 



month, while in September there were nearly three inches in 



the earl\- ■|)art of the nionlli and at least fair rains near -the 



