t68 Mosquitoes 



the larvae thrive in a saturated solution of fecal mat- 

 ter. Drying for over six and one-half hours, or before 

 they darken, effectually kills the eggs, which resist 

 desiccation better if the raft is broken up, just as they 

 will hatch if broken apart and submerged, but will not 

 do so if the whole raft is sunk. When the dark rafts 

 are dried, the eggs cave in somewhat, but swell again 

 if placed on water before they are dead. The adults 

 bite twelve hours after emergence, and will some- 

 times feed twice after emptying the ovaries. Bred 

 specimens which were never allowed to make a meal 

 of blood, mated and laid fertile eggs. The larval life 

 is from six to ten days, the pupal one to three. The 

 larvae are found in any ditch, vacant lot pool, sewer 

 trap or cesspool, or any other place near town, in- 

 doors or out. When there is not enough food, or 

 the weather is cold, the larval period is prolonged 

 and the adult dwarfed, says Dr. Smith. Insufficiency 

 of food produces small imagos of any species ; more- 

 over these starved adults are dark and not well 

 marked. Drying up the water causes a hurried 

 maturation, with the same effect. On the western 

 coast, pipiens, while present, is largely replaced as the 

 great domestic pest by Theobaldia incidens, which, 

 although not resembling pipiens, breeds there just as 

 does the latter in the east. 



Culex restuans. — Close to pipiens in habits 

 and appearance is Culex restuans, distinguished 

 in perfect specimens by the two or four small, 

 light spots on the thorax (Fig. 6, a, page 

 31). It is generally a trifle smaller than and not 

 so lean as the former. It multiplies in barrels, 



