200 FIELD ZOOLOGY 



some hollow in the ground where the water stands only 

 occasionally, and where the eggs will hatch in install- 

 ments. Another species of mosquito deposits its eggs 

 singly; the eggs sink to the bottom of the pond, where 

 they remain till the following spring before they hatch. 

 Government experts tell us that the normal food of adult 

 mosquitoes is probably plant juices, and that the taste 

 for blood is probably an acquired habit. If that is true, 

 we certainly have reason to be thankful that the blood- 

 sucking habit is confined to the females of our dangerous 

 mosquitoes. 



Small fish are by far the most important natural 

 enemies of mosquitoes. The carnivorous minnows, the 

 sticklebacks, the sunfish, are all efficient destroyers of the 

 larvae in permanent pools of water. The common gold 

 fish does good service in similar places. Aquatic insects, 

 such as the water scavengers, the diving beetles, dragon- 

 fly larvae, all are valuable allies of man in getting rid of 

 immense numbers of eggs, larvae, and pupae. Adult 

 mosquitoes are devoured by bats, night-hawks, swallows, 

 martins, and flycatchers, as well as by the adult dragon 

 flies. These last-named seem to have special preference 

 for a mosquito diet, for which we ought to be so thankful 

 that we would never kill a dragon fly needlessly. It is 

 said that the streets and houses of Honolulu would be 

 practically uninhabitable if it were not for the dragon 

 flies that hunt the mosquito swarms constantly (Kellogg) . 



Mosquitoes in the adult stage are also attacked by 

 certain fungous diseases similar to those which attack 

 our house flies, and leave their bodies mere shells, filled 

 with the hyphal growth of the plant. 



On the part of man in the attempt to destroy these 

 disease carriers, the first step is to drain every pool or 



