104 THE REPORT OF THE No. 19 



They hatcli in a week if the weather is warm; and the little white mag-gots 

 work their way down between the leaf and the stem of the plant, till they 

 come to a joint; there they commence to drain away the juices of the plant. 

 About the first of June, the maggots go into what is called the "Flaxseed 

 stage," because of the shape and color of the pupa case, or "puparium." 

 The perfect insects appear in August, and lay their eggs for the second brood. 

 Where Fall Wheat is grown it should not be sown till September ; and 

 Spring Wheat should not be sown till the end of May. 



Diplosis tritici became very destructive in Lower Canada in 1834. In 

 1856 it was estimated that the loss on wheat in Canada, occasioned by the 

 Midge was |2, 500, 000. The perfect insect is a minute, orange-colored fly, 

 with black eyes, yellow legs, and wings that resemble thin films of mica. 

 It makes its appearance when the wheat is in flower; and the female lays 

 her eggs in the floret — the harm done by this insect is directly to the ker- 

 nel (Fig. 35). The maggots get their growth in three weeks, and then 

 wriggle to the ground and bury themselves, remaining unchanged through 

 the Winter, and going into pupa in the Spring. The flies come forth in 

 ihe end of June. Because of the damage done by this insect, and because 

 Western flour can be bought so cheaply, our farmers in Quebec Province 

 nave, very generally, abandoned the growth of wheat. 



A very interesting Cecidomyian is C. strohiloides,, Osten Sacken (Fig. 

 36). This fly lays an &gg in the terminal bud of a shoot of sallow. The 

 little orange-colored grub that comes from the eg^ so affects the bud, that 

 it develops into a good-sized cone-shaped gall, which becomes dry and hard 

 as the Winter advances. In the centre of this gall, and in a delicate, mem- 

 braneous cocoon, the grub remains till early Spring, when it changes to a 

 pupa. In April or May the perfect flies appear. When I was studying 

 these creatures I opened some of the galls to watch the changes of the in- 

 sect, and, as I thought, to aid the prisoner to escape, but the interference 

 did harm ; the fly from the open gall was always defective — as we f^ay "crip- 

 pled." It seemed as if the effort on the part of the insect to work its way 

 upward, was absolutely necessary to the attainment of its higher life. And 

 in this we have one of Nature's many parables. 



A fly of great economic importance is Diplosis grassator, Fyles (Fig. 

 37), which in this country preys upon and keeps down the numbers of the 

 dreaded Phylloxera 'vastatrix, Planchon. 



The story of my discovery of this insect is as follows : 



In the summer of 1882, I spent some time at Como, on the Ottawa with 

 my friends, Mr. and Mrs. I. J. Gibb. Growing over the fences of the high- 

 way which ran through their estate, and extending for many yards, were 

 several native vines. They were badly infested ^\'\i\\ PTiylloxera vas- 

 tatrix. As this pest was then exciting much attention, I was pleased with 

 the opportunity of studying its habits. I soon found that at this place it 

 was assailed by a formidable foe, an orange-colored dipterous larva. The 

 business-like way in which this creature gave the quietus to the larva of the 

 Phylloxera aroused my curiosity, and I resolved to study the species care- 

 fully. Accordingly I took a mass of the affected foliage home to Cowans- 

 ville, where I then resided, and arranged for fresh supplies, properly secured, 

 to be sent to me by post. At home I spent much time at the microscope, 

 observing the structure, habits, and metamorphoses of the species ; and I 

 made, with the utmost care, drawings of it in its larval, pupal, and imago 

 stages. 



The Annual Meeting of the Entomological Society of Ontario was held 

 that year in Montreal, and was attended by a number of scientists from the 



