CAN THE MOSQUITO PEST BE MITIGATED? 681 



reproduction. To suppose that the tormenting of man occupies 

 any considerable time in the mosquito economy is certainly a mis- 

 take. It is only the female which can thus make our lives miser- 

 able/' They are local in their range, and the supposition that 

 they can be carried long distances by the wind is declared a mis- 

 take. House-flies are omnipresent with us, while mosquitoes appear 

 only in spots. According to Packard, " fresh horse-manure, with 

 plenty of heat and moisture, furnishes the best food for the young 

 maggot. From a hundred to a hundred and fifty eggs are de- 

 posited in irregular, loose sacs, usually within eighteen hours, and 

 hatching in twenty-four hours or less. The maggots molt twice ; 

 the three stages of larval development being of the following 

 periods : first stage, one day ; second stage, from twenty-four to 

 thirty-six hours ; third stage, three or four days. To this maxi- 

 mum period of seven days is to be added the same length of time 

 for the pupal life ; thus it will be seen that fifteen or sixteen days 

 are required for the entire development from egg to imago." 



The expediency of trying to exterminate them is more than 

 doubtful, for, according to the same author, " it should be remem- 

 bered that flies have an infancy as maggots, and the loathsome 

 life they lead as scavengers cleanses and purifies the August air, 

 and lowers the death-rate of our cities and towns. Thus the young 

 of the house-fly, the flesh-fly, and the blow-fly, with their thousand 

 allies, are doing something toward purifying the pestilential air 

 and averting the summer brood of cholera, diphtheria, and typhoid 

 fevers which descend like harpies upon the towns and cities. It is 

 a useful species, to which man owes more than he can readily esti- 

 mate, and with which he can dispense only when the health of our 

 cities and towns is looked after with greater vigilance and intelli- 

 gence than is perhaps likely to be the case for several centuries to 



come." 



Mosquitoes, therefore, are entitled to exclusive attention in the 

 exterminating effort. 



Mrs. Aaron has a poor opinion of the efficiency of the dragon- 

 flies, or Odonats, as mosquito-destroyers. They become rarer about 

 the time that the mosquitoes are most numerous. In the matter 

 of flight they are very local, and it seems impossible to conceive 

 that they could ever be brought to frequent deep woods or city 

 streets where mosquitoes abound. The author's observations of 

 their feeding habits lead her to believe that they prefer robust, 

 meaty insects, and that studies of their appetites in confinement 

 are misleading. The habit of migration among them will also 

 militate against their efficiency as mosquito-destroyers. 



Other writers find that they are capable, in natural conditions, 

 of working great havoc among mosquitoes, but doubt the utility 

 of efforts to improve on nature in the matter. Captain C. B. N. 



