178 BOARD OF AGRICULTURE. 



Ceratopogon, like the musqtiito, is a blood-sucker, has the male 

 antennre partially feathered, and the larvoe live in mushrooms, 

 or under the bark of decaying trees. 



Gecidomxjia. Gall flies have slender bodies and verticillate an- 

 tennae, their wings have few nervures, and are placed rool-like 

 over the body. The female lays her eggs in the stalks of cereals, 

 and of stems and leaves, which produce galls inhabited by maggots. 

 The Hessian fly does not, however, produce an enlargement of the 

 stalk, as is usual. Those species injurious to wheat, &c., can be 

 collected by sweeping the fields in the spring, at evening, when 

 they are laying their eggs. 



Psyehoda is a minute genus, with white, broad, oval wings, which 

 is found flying about and into, little pools, and in great numbers on 

 windows. The larvfe live in dung. 



The Mycelophilldce are of small size, and very active, leaping little 

 flies, which are found in damp places. The larvge are long, nearly 

 I'ound, white or yellowish ; they are gregarious, living in decaying 

 vegeiable matter, fungi, or in dung, one species forming a gall. 

 Rhyphus is common on windows ; it has rather broad, spotted 

 wings, and the larva lives in cow dung. The large Tipulce, which 

 fly all the summer and form a numerous group, live as larvae in the 

 mould of gardens, at the roots of willows, and in rotten wood. The 

 pupa have the margins of the rings spiny, to be able to push them- 

 selves along, as do many other Diptera. Other species are aquatic, 

 and should be raised in aquaria. Chionea, the snow-gnat, looks 

 like a spider, being wingless, and is found in March on the snow. 



The Bibionidce comprise species very injurious from their feeding 

 on the roots of grass ; the thorax is stout, and the legs are short. 

 B. albipennis flies in swarms in June and October, alighting slowly 

 on the passer-by. Simulium, the black fly, has a stout body and 

 short legs, often silvery in color. It is aquatic, its larva living on 

 the stems of plants. 



Slratxomyida^. The insects of the following families have broad 

 bodies, and short, bristle-like antennae, the basal joints being en- 

 larged. Those of this family are found among herbage in damp 

 places. The larvae live in the water, in decaying subtances or 

 dung. 



Tabanidce, Horse-flies. Tlie parts of the mouth are here again 

 converted into a proboscis. The horse-flies are of large size, and 

 troublesome from their formidable bite. Their eyes are very large, 



