51 



however, that this is a grass as well as a grain insect, and eradication 

 from the grain fields will not protect from infestation from without. 



NATURAL ENEMIES. 



The abundance of one of these and the extent to which they are 

 able to perform their deadly work is a most encouraging feature, 

 viewed from the standpoint of the husbandman. A small, shining 

 black, four-winged tl}^, with reddish-yellow legs {CcBliiikis ineroinyzde, 

 Forbes), is exceeding beneficial in its parasitic work on the maggots of 

 this pest. This parasite was discovered and described by Doctor 

 Forbes in connection with the investigations of the outbreak in Illinois 

 in 1883. So abundant is this parasite that it is almost impossible to rear 

 the flies from the straws in July without also rearing numbers of these 

 diminutive friends. They attack the maggots by placing their eggs in 

 their l)odies, and the eggs hatching feed upon the maggots and destroy 

 them. This parasite occurs generallv with the depredator, even in 

 the far North. 



Another natural enemy is the mite Pediculoides {Heteropus) ventri- 

 cosits Newport, illustrated on page 22. The young of this insect are 

 so ver}^ minute as to be quite invisible to the unaided eye. They are 

 without wings, but very active, and make their way to the maggot 

 working within the stem and fastening themselves upon it suck its 

 blood, in the meantime themselves increasing rapidly in size until 

 the}^ appear like minute globular eggs, the abdomen being distended 

 with young, as there are no males, and the body having much the 

 proportions the stem has to the pumpkin. Each female gives birth 

 to a great number of young, which at once either escape to other stems 

 to hunt out their victims or else settle down with the parent. These 

 are frequently found attacking the maggots and are apt to escape 

 detection, or, if observed, mistaken for eggs. The reference in the 

 Prairie Farmer, calling attention to the presence of what probably 

 were these maggots in stems of wheat previously cited, also mentioned 

 the presence of nine eggs with the maggot. Without a doubt these 

 were the mites that had attacked the maggot, though this was long 

 before the mite was known to inhabit this country, it being a native 

 of Europe, as far as now known. 



THE LESSER WHEAT STEM-MAGGOT. 



( Oscinis carbonaria Loew. Fig. 15, d. ) 



With our present knowledge of the early stages of development it 

 is yet impossible for me to separate out from several other allied 

 species such as belong to this one and give a detailed account of its 

 life cycle, and especially is this true with reference to Oscmis soror\ 

 or what is the same thing, Oscinis variabilis Loew. To be able to do 

 this will require the most careful and exact studies of the early stages 



