58 



PARASITES OF THE DOMESTIC ANIMALS 



in the southern portion as far north as Illinois, Iowa, and Nebraska. 

 It makes its appearance in the spring or early summer and is at once 

 attracted to cattle, depositing its eggs on the hairs, frequently upon 

 those about the heel, a habit which gives to the fly its southwestern 

 name "heel-fly." 



The entire length of the egg is 1 mm. and its width 0.2 mm. In color 

 it is a yellowish white. The eggs are firmly attached to the hairs by 



means of a clasping projec- 

 tion which connects with 

 the egg proper by a short 

 pedicle (Fig. 31). Usually 

 they are deposited upon 

 the hairs in groups of four 

 to six. 



Hypoderma Bovis. — CEs- 

 tridse (p. 53). This species 

 is commonly referred to as 

 the European warble fly, 

 though it occurs also in 

 Canada and the United 

 States. It is, in fact, said 

 to be more common in some 

 parts of this country than 

 H. lineata. Its length, ex- 

 clusive of the ovipositor, as 

 stated by Neumann, is 13 

 to 15 mm. {}/2 to ^/g of an 

 inch), which is 1 to 2 mm. 

 longer than H. lineata. The 

 general color is black, face 

 gray; abdomen black; head, 

 thorax, and abdomen hairy. 

 The hairs from the base to the tip of the abdomen vary in color from 

 white or yellow to black; orange red at posterior third. The legs are 

 black, yellow at their terminations; wings somewhat brown. 



As to the differentiation of the larvae of these two species, Herms 

 writes as follows: "The life history of the two species is very similar. 

 The larvse are different enough to distinguish them readily. The fully 

 grown larva of H. bovis is longer, 27 to 28 mm., H. lineata about 25 mm. 

 The two species are distinguished on the basis of their spiny armature. 

 In H. lineata each segment of the larva is provided with spines except 

 the last, the ring upon which the stigmata are located, while in H. bovis 

 all except the last two are armored." 



Life History. — Dr. Cooper Curtice, from his researches in 1890, 



Fig. 29. — Hypoderma lineata (after Osborn, from 

 Insect Life, Bui. No. 5, Bureau of Entomology, U. S. 

 Dept. of Agr.). 



