61 



in the g-rain field.s must be made somewhat at random and aimed at 

 Oscinidie in general rather than at this particular species. 



REMEDIAL AND PREVENTIVE MEASURES. 



Over the area where winter wheat is cultivated the same measures 

 that have been urged against the two wheat stem-maggots will apply 

 equally well here, so far as we now understand the habits of this 

 species. These are the destruction of volunteer wheat, the burning 

 over of waste grass lands in winter and early spring, and late sowing 

 of the grain in fall. In spring- wheat regions the experience of Doctor 

 Lugger in Minnesota is stronglv indicative of the effect of plowing the 

 infested lields as soon as possible after the crop has been removed. 

 He states that in the fall of 1891 and spring of 1892 not more than 

 one-half of the acreage of wheat land was plowed, owing to unusually 

 wet weather during these periods, and the pest that had gained a foot- 

 hold, as it were, in 1891, meeting with no reverses on account of lack 

 of plowing, simply continuing to increase in numbers, with the result 

 that in 1892 it committed serious and widespread depredations. Where 

 the lields can be burned over in fall or spring the result will, of course, 

 be the extermination of the pest in such fields in the northern portions 

 of the country, but farther south it is the grass lands that need to be 

 burned over, since there is no way of reaching the insect hibernating 

 in the winter-wheat plants. The fields of spring wheat in the North 

 will, of course, be to some extent also protected by the burning over 

 of the grass lands in fall or spring. 



DESCRIPTION. 



The difference between this species and Osckds mrhmav'm have 

 already been pointed out in the treatment of the latter species (see 

 p. 55). 



Larva. — This very closely resembles that of O. carhonaria., as is 

 shown by the illustrations used by Doctor Lugger in his publications. 

 He states, however, that the larva is of a greenish-white color when 

 alive and just removed from the culm. 



Pupariwn. — Here, again, it would be difficult to identify the pupa- 

 rium by either the illustration or description given by Doctor Lugger, 

 as both closely resemble those given of O. varlahiUsf by Professor 

 Garman. Doctor Lugger describes this as being of a glossy chestnut- 

 brown color, shading to yellowish brown toward the smaller end, and 

 showing faint traces of sutures or segments. 



Of the other species of small Oscinidse whose larva3 arc found in and 

 about the stems of growing grain I have already written, and it is 

 impossible with our present knowledge of them to go into further 

 details. Some of these may bo destructive and some may not, as the 

 fact of these having been reared from grain plants does not necessiirily 



