REPORT OF THE STATE ENTOMOLOGIST IQlS 37 



Signs of infestation. White heads or " false heads " in rye fields 

 are very suggestive of wheat midge, though they may be produced 

 by other causes. The white heads are generally empty, usually 

 because the maggots have deserted them before the abnormal colora- 

 tion attracted notice. A yellowish cast showing through the bracts 

 covering the grain indicates the probable presence of small yellowish 

 or orange-colored maggots and occasionally such heads may contain 

 unexpected numbers of the pest. This yellowish color is seen only 

 upon a moderately close examination. 



There are no equally marked signs of infestation in wheat heads 

 owing to the fact that the more yellowish glumes protecting the wheat 

 grains tend to conceal the yellowish maggots sheltering beneath. 

 It is comparatively easy to tear open a few heads and the presence 

 of maggots is indubitable evidence of infestation. One of the easiest 

 ways of making an examination of ripening grain is to rub heads to 

 pieces in the hollow of the hand and in most instances, if the pest is 

 present, the minute yellowish maggots will drop out of the bracts. 

 This method gives an approximate indication of the extent of injury 

 and if from five to ten maggots are commonly found in a head the 

 infestation may be considered moderately serious. 



Description. The small yellowish midges are delicate flies about 

 one-sixteenth of an inch in length and with wings showing beautiful 

 violet reflections. The male is easily recognized by its rather long, 

 thickly haired antennae, apparently with nearly twice as many seg- 

 ments as are found in the much shorter, more sparsely haired antennae 

 of the female. These midges do not present characters apparent 

 to the unaided eye which can be depended upon for their recognition 

 in the field, though the chances are that small flies presenting the 

 above characteristics and numerous in the wheat fields at the time the 

 heads are beginning to develop would belong to this species. 



The maggots or larvae are pale yellowish when young and yellow- 

 ish orange when full grown, moderately stout and at maturity about 

 one-tenth of an inch long. They, like many gall midge larvae, have 

 a distinct brown breastbone on the under side of the anterior extrem- 

 ity, and are able to snap or throw themselves an inch or so. Maggots 

 presenting these general characters and occurring in the heads of 

 wheat and rye are in all probability those of this species. 



Recognition of these small insects is difficult and to aid those who 

 wish to make a more serious study of the insect, the following tech- 

 nical descriptions have been drafted. 



Larva. Length 2.5 mm, yellowish orange, stout. Head small, 

 rather long; antennae stout, biarticulate ; breastbone bidentate, the 

 teeth diverging, obliquely truncate, the shaft long, slender and 



