34 



but in colour are a reddish brown. The perfect fly bursts from the pupa-case in six or 

 seven days. Seen under the microscope it is a remarkable and beautiful object. Its 

 eyes are compound, each presenting four thousand facets. Its wings are beautifully 

 hyaline, flashing in the light rich tints of purple and crimson. 

 The labium, or tongue, terminates in a sucking disk, divided 

 into two leaves, which are ribbed underneath like a rasp (Fig. 

 18). It is the friction of these ribs which leaves the sensation 

 of a bite upon the skin, when the insect has tried its powers 

 upon us. 



Insects belonging to the genus Musca are very prolific. 

 Leeuwenhock calculated that in three months, the natural and 

 unchecked increase from one pair of flies would be 700,000. 

 Yast numbers of the maggots of the house-fly are eaten by 

 domestic poultry, and vast numbers of the perfect insects by 

 hornets and wasps. The fly, moreover, is subject to a strange 

 disease, in which the abdomen becomes distended and a fluffy 

 substance appears in the joints. The fungus is Sporendonema 

 muscoe,. It spreads through the system, saps the life and the fly succumbs. 



Much may be done to keep down the numbers of the house-fly. The horse-barn 

 should be placed at a distance from the dwelling house. The manure pile should be 

 frequently turned, and the poultry allowed free access to it. The house should be 

 supplied with doors and blinds of gauze-wire or netting, which will admit light and air, 

 so necessary to the health of the inmates, and shut out flies and other intruders. Care 

 should be taken to destroy every fly that shows itself in the winter — hibernating insects 

 will start fresh colonies in the spring. A simple and very effective fly-trap may be made 

 thus : — Fill a tumbler to within an inch of the top with strong soap-suds. Take a slice 

 of bread, cut in the centre of it a hole about an inch in diameter ; moisten the under 

 surface ; spread it freely with Muscovado sugar ; place it with the sugared surface down- 

 ward, over the tumbler, so that the hole may come in the centre. The flies will soon 

 discover the sugar, descend through the hole, and very soon attempting to fly, will be 

 engulfed. When the flies blacken the suds they can be taken out and thrown into the 

 stove. 



Fig. 18. 



Fig. 19. 



Fig. 20. 



2. The Mosquito (Culex ) belongs to the family Cidicidce in the order Diptera. 



Several species of the genus Culex are assigned to British North America. The names 

 of these different species are suggestive, — excrutians, impatiens, i?nplacabilis, pro- 

 vocans, stimulans, etc. The mosquito lays her eggs in a boat-shaped mass on the surface 

 of the water. She delights in pools, for her progeny feed upon the decaying matter which 

 abounds in stagnant water. They are familiarly known as " wrigglers." They are often 

 seen in rain-water which has been allowed to remain too long in the butt. The breathing 

 apparatus of the larva is situated at the extremity of the body, and is described by 

 Packard as a " star-like respiratory tube which connects with the tracheae." The creature 

 is often seen hanging with its head downwards and its respiratory organ at the surface of 



