DIPTERA. 69 



grey, sometimes brown, 'bristling with small black turbercles ; the ab- 

 domen white, spotted with brown or black ; and the wings hyaline. 



The Cephalemyia (CEstrus) ovis is to be found in Europe, Arabia, 

 Persia, and in the East Indies. It lays its eggs on the edges of the 

 animal's nostrils, and the larva lives in the frontal and maxillary 

 sinuses. It is a whitish worm, having a black transverse band on 

 each of its segments. Its head is armed with two horny black 

 hooks, parallel, and capable of being moved up and down and 

 laterally. Underneath, each segment of the body has several rows 

 of tubercles of nearly spherical form, surmounted by small bristles 

 having reddish points, and all of them bent backwards. "These 

 points," says M. Joly, " probably serve to facilitate the progress of 

 the animal on the smooth and slippery surfaces of the mucous 

 membranes to which it fixes itself to feed, and perhaps also to 

 increase the secretion of these membranes by the irritation occasioned 

 by the bristles with which they are furnished."* 



Fixed by means of these hooks to the mucous membrane, which 

 it perforates, the larva nourishes itself 

 with mucus, and lives in this state, 

 according to M. Joly, during nearly a 

 whole year. A,t the end of this time 

 it comes out, following the same course 

 by which it entered, falls to the ground, 

 and burying itself to the depth of a 

 few inches, is transformed into a pupa. 

 The cocoon is of a fine black colour. 

 Thirty or forty days after its burial it 

 emerges in the perfect state, and de- ^ 50 _ Conop& 



taching the lid at the anterior end of 

 the cocoon by the aid of its head, which has increased considerably 

 in size, takes flight. 



Notwithstanding the formidable appearance of their trunks, the 

 habits of the perfect Conopes (Fig. 50) are very quiet. In the adult 

 state they are only to be seen on flowers, of which they suck the 

 honeyed juice. But with their larvae the case is otherwise. These 

 latter live as parasites on the humble-bees (Bombt). Latreille saw the 

 Conops rufipes issue in the perfect state from the body of a humble- 

 bee, through the intervals of the segments of the abdomen. 



* " Recherches sur les CEstrides en general, et particulierement sur les CEstres 

 qui attaquent 1'homme, le cheval, le bceuf, et le mouton." Par N. Joly, Pro- 

 fesseur a la Faculte des Sciences de Toulouse. P. 63. Lyons, 1846. 



