MOSQUITOES 



131 



Its respiratory tube is short, its body black and spotted with 

 tufts of long bristles protruding from the sides (Fig. 62). The 

 pupa3 of the different species are not readily distinguished. 

 Under favorable conditions the time required for the eggs to 

 hatch and grow to adult mosquitoes is ten days ; when the 

 weather is cold it may be indefinitely 

 extended. Three days after emergence 

 the adult may lay eggs. Culex has pro- 

 duced from seven to ten generations in 

 a season and Anopheles four. Allowing 

 150 eggs to a generation, the possible 

 progeny of a pair of Anopheles in one 

 season would be 31,000,000. The natu- 

 ral enemies of immature mosquitoes are 

 fishes, newts, salamanders, dragon-fly 

 nymphs, the larvae of water beetles, and 

 even young turtles. 



Location of breeding places. After 

 members of the class have learned to 

 distinguish the different mosquitoes and 

 their larvae at a glance, they should 

 divide themselves into groups corre- 

 sponding to convenient divisions of the 

 district to be studied. Each group should 

 be responsible for a full report upon the 

 breeding places and the kind of mosqui- 

 toes found in its territory. Collect speci- 

 mens and put the eggs, larvae, and pupae 

 from each territory into separate glasses 

 or into vivaria with screen tops (Fig. 69). Keep a dish of 

 water and a bit of fruit (apple, grape, banana) in the vivaria 

 for the adults and have green algae in the water with the 

 larvae. Catch full-fed mosquitoes about animals or in bed- 

 rooms and keep in glasses arranged as shown in Fig. 70. 



F i G . 68 . Insect-catching 

 bottle 



For handling delicate in- 

 sects this is better than a 

 net. The essential feature 

 is a paper cone opening in- 

 ward through the thin cork 



