114. THE MOSQUITOES OF NEW JERSEY 



HABITS OF THE EARLY STAGES 



This is the earliest and latest of the species that winter in the egg 

 stage: earliest as to both adult and larva, and latest as to larva only. 

 The extreme records for either direction show larvae hatched in No- 

 vember and again in the February following. That the February larvae 

 did not hibernate as such is abundantly proved by the almost daily col- 

 lections made during February, 1903, by the fact that larvae developed 

 in water with a portion of the mud bottom from woodland pools and, 

 finally, by the fact that I found the eggs in some samples of mud from 

 the bottom of breeding pools sent in to me for examination at my re- 

 quest. 



It was positively proved that during the early days of February, in 

 water just above the freezing temperature (36°F.), the larvae of cana- 

 densis may and do hatch from the egg under entirely natural conditions. 

 Hatching may be hastened by disturbing the material in which the eggs 

 are laid, and this probably accounts for the larvae first found in the 

 jars. 



February, 1903, was a cold month and the breeding pools in which 

 the larvae were found became iced over several times, so as to bar ab- 

 solutely all access to the surface; nevertheless, there was no apparent 

 decrease in the number of specimens, but, on the contrary, a continuous 

 increase. Artificial tests were made February 18 and 19, when the bot- 

 tles with baby larvae were allowed to freeze almost solid. Nevertheless 

 they survived the test and specimens could be watched partly imbedded 

 in ice, wriggling to free themselves until the surrounding temperature 

 rose sufficiently to release the ice grip. In nature the larvae usually 

 manage to escape actual freezing by getting into the bottom mud, and 

 that was illustrated by an examination made March 2, after a night 

 when the thermometer registered 23°. The pool was completely ice 

 covered, a hole was chopped near the edge with an ax, and through 

 this hole larvae were dipped up in fair numbers with the bottom mate- 

 rial. No larvae were imbedded in the ice. 



Development at this season is slow and the new hatchings during 

 early March rapidly overhauled those that appeared earlier, so that by 

 the middle of that month the great bulk of the brood was about half 

 grown or a little larger. The pupal period ranges from two to seven 

 days, according to temperature. 



The earliest record for adults taken outdoors is April 14. It is not 

 until the early days of May, however, that both sexes are at all abun- 

 dant, and at that time not all of the hibernated eggs are yet hatched. 



