THE INSECT WORLD. 



333 



The impregnated females live through the winter, hiding wherever 

 they can find sheher, — in cellars, attics, barns, out-houses, piles 

 of rubbish, hollow trees, etc. As soon as warm weather returns 

 they begin to reproduce, and several broods are matured during 

 the summer. 



In the larval stage the insects are scavengers, serving a good 

 purpose in keeping the water in which they live pure and clean ; 

 but as adults they are unmitigated nuisances, rendering some 

 parts of our country almost uninhabitable. 



Where the opportunities for breeding are few, the insects can 

 be checked to an extent by keeping cisterns and rain-barrels 

 well covered, and by pouring on the surface of all ponds and 

 puddles a small quantity of kerosene. The oil spreads in a thin 

 film over the entire surface, and all larvae and pupae when they 

 come to the surface to breathe are killed at once. Many females 

 are also killed while attempting to oviposit. In favorably located 

 regions the mosquito plague may be at least greatly lessened by 

 this method. 



Where exposure to mosquito attack is unavoidable, the follow- 

 ing mixture will serve to keep off the pests : 



Oil of pennyroyal i part. 



Oil of tar 2 parts. 



Olive or cottonseed oil 2 parts. 



Rub all exposed parts with this mixture, which will secure ex- 

 emption for from one to two hours or longer without renewal, 

 depending upon the temperature and the amount of perspira- 

 tion. 



It remains only to say that, as mosquitoes sometimes occur in 

 swarms in arid regions, many miles from water, it is likely that 

 their larvae in some cases inhabit the soil. 



Closely resembling mosquitoes in appearance are the Chiro- 

 nomidcs, which may be recognized by the naked wings and by 

 having the thorax produced so as to hide the small head from 

 above. The antennae are feathered in both sexes, those of the 

 male strikingly plumose. To this family belong the gnats or 

 midges which may sometimes be seen dancing in swarms in the 

 evening only a few feet above ground, generally early in the 

 year and in damp places. The larvae are mostly aquatic, and 



