40 NEW YORK STATE MUSEUM 



many of the maggots developing successfully. They presumably 

 succumb to the lack of moisture in much the same way as the 

 parent flies. 



The small maggots are at first whitish transparent with a greenish 

 tinge, becoming yellowish orange when nearly full grown. They 

 obtain their nourishment by absorbing plant fluids from the adjacent 

 grains and husks. This drain upon the vitality of the plant reduces 

 the size of the kernels of wheat and if the infestation is severe may 

 blast a considerable proportion or in extreme cases all the grain. 

 The maggots become full grown shortly before the wheat hardens 

 and then desert the heads in large numbers. They wriggle out during 

 a rain or when there is a heavy dew, descend the stalks or drop to 

 the ground and establish themselves in the upper layers of the soil, 

 probably rarely penetrating to more than an inch below the surface. 

 Under some conditions considerable numbers of the maggots remain 

 in the wheat heads, are can-ied with the grain to the thrashing 

 machine and are thrown out with the chaff. Occasionally these 

 yellowish maggots form a considerable proportion of the screenings. 



It will be seen from the above that the number of maggots in a 

 wheat head is variable, much depending upon weather conditions 

 immediately preceding. The presence of a large number indicates a 

 serious infestation while the absence of maggots is simply of negative 

 value. They may have been in the head earlier and deserted it or 

 there may have been no infestation. Many shrunken grains or 

 empty husks under such conditions is evidence that something has 

 prevented the normal development and in not a few cases most of 

 the injury may be due to an infestation by the maggots of this midge. 



Wagner, who studied the European wheat midge (tritici) and the 

 Moselle midge (mosellana) about 1865, states that flies may be abroad 

 for 6 or 7 weeks, that they are active all night and that quack grass 

 is a host plant as well as rye and wheat, the Moselle midge apparently 

 showing a greater preference for rye than wheat. This last observa- 

 tion is hardly confirmed by conditions found in western New York. 

 In this connection it should be remembered that infestation is very 

 probably proportional in large measure at least to the condition of 

 the grain at the time the flies are most abundant. He states that 

 these midges begin to oviposit as soon as the heads appear and 

 continue until blossoming of the grain, and adds that the two species 

 have such similar habits that what is true of one appHes largely to 

 the other. It follows from the last that American records in regard 

 to life history are of most value for our purposes since they relate 



