EXPERIMENT STATION BULLETINS. 



211 



WHEAT MIDGE. 



[Dip losis tritici. ) 



Minute reddish maggots, inside the flower or next the kernel of wheat, which maggots 

 deform and shrivel the berry. 



As long ago as 1874, Professor Cook, tlien of this station, records 

 the presence of the wheat-midge or red weevil, and since that time we 

 have heard of its presence here and there in restricted areas. Last year 

 it appeared hoi-o at the College, in snfficient numbers to attract atten- 

 tion. > 



Fig. 8. Wheat-midge, greatly "enlarged, from photo, 26 July, 1906 (Original). 



The larvae of the wheat-midge are very small, and several may inhabit 

 a single flower of wheat. The eggs are laid by tiny, yellowish flies on 

 the glumes or chaffy envelopes of the flowers. The maggots travel down 

 ihto the region about the forming seed, where part of the juice of the 

 young kernel is extracted in some way, the result being seen in the shriv- 

 eled grain when threshed. The heads are also poorly filled, and when the 

 midges are plentiful, the result is very disappointing. There is usually 

 but one brood each year, although there is reason to suspect the presence 

 of a partial second crop of the adults at least. 



When full-grown, the larva descends to the ground and buries itself 

 under the surface. The descent is often aided by rains, which wash out 

 the tiny creatures and carry them down, others, no doubt, drop and 

 wriggle their way down. During June of the following year the flies 

 come forth and lay their eggs. Wet weather and warmth favors their 

 increase, while cold, dry weather proves unfavorable. 



