Decembeu 11, U)03.] 



SCIENCE. 



uvs 



Culex sollicilans is always the sumincr pest 

 in the Jersey Pines — even where there is no 

 water of any kind, and yet I had never been 

 able to find in the swamps any larva;. Jlr. 

 J. Turner Brakeley, who had made observa- 

 tions for me in previous years, began, early 

 in this year, a systematic search in all the 

 breeding areas near his cranberry bogs at 

 Lahaway, over twenty miles in a direct line 

 from the shore and nearly forty miles from the 

 Mullica Eiver marshes. He worked out the 

 early life history of Culex canadensis, the 

 winter history of Culex melanurus and dis- 

 covered an entirely new species, Culex aurifer; 

 but he failed absolutely to find any larvse of 

 Culex sollicitans. Nor did he see even the 

 adults of that species until late in July; up 

 to which time the pines were practically 

 mosquito-free. 



Dr. Julius Nelson, biologist to the New 

 Jersey experiment stations, was engaged in 

 oyster investigations on the marshes near 

 Tuckerton during July and, incidentally, kept 

 an eye on mosquito conditions for my benefit. 

 Up to about July 12 the marshes were quite 

 free from both adults and larvae; but on that 

 date an unusually high tide covered them and, 

 on the 13th, minute wrigglers of C. sollicitans 

 were in every water-filled hole. July 21 the 

 males emerged in clouds and only pupse were 

 in the water. Females were out on the 22d 

 but would not bite. On the evening of the 

 23d it was warm, with only a light breeze, 

 and just at dusk a peculiar humming noise 

 seemed to fill the air. The source of this was 

 located at a height of between sixteen and 

 twenty feet above the marsh, where clouds of 

 mosquitoes hovered in their marriage flight. 

 On the 24th few males were seen; but the 

 females were now in droves and bloodthirsty 

 as butchers. Then came cold north and west 

 winds that kept the insects low down among 

 the grass. On the 28th the wind veered to the 

 south find continued so all that night and all 

 day on the 29th. On the morning of the 29th 

 the number of mosquitoes on the marsh had 

 diminished materially, and this was yet more 

 decidedly marked on the morning of the 30th 

 when they were quite bearable. But in the 

 wof)ds, where on the 20th there had been few 



mosquitoes, they were worse on the 31st, when 

 Dr. Xelson came out to Tuckerton, than they 

 were on the marsh itself. 



Dr. Nelson gave me this record on his re- 

 turn to New Brunswick and next morning 

 came a letter from Mr. Brakeley who in pre- 

 vious communications had uniformly reported 

 ' no salts.' Now, however, he sent in great 

 detail, accompanied by specimens as vouchers, 

 a report of how, during the night of July 

 28-29, Culex sollicitans had arrived in swarms 

 and hov?, during the two nights following, the 

 entire pine region for several miles round 

 about had become infested. Of the testimony 

 gathered by Jlr. Brakeley one item is espe- 

 cially important — a farmer driving out for a 

 doctor early in the evening through a mos- 

 quito-free wood and coming back late to fintl 

 it swarming with bloodthirsty specimens. 



Lahaway is exactly in the line of a flight 

 on a south wind from the Mullica River, the 

 distance to be covered is between thirty and 

 forty miles, and the two series of entirely 

 indeijendent observations are altogether too 

 closely congruent to be set aside as accidental 

 and unconnected. The known antecedent con- 

 ditions and the completeness of the observa- 

 tions leave only one possible explanation. 

 The mosquitoes that left the marshes on the 

 evening of July 28 reached the pines, over 

 thirty miles north, before daylight next morn- 

 ing. ^Vllat I have given here are examples of 

 the kind of evidence that I have accumulated. 

 It is not a series of isolated observations, but 

 a daily record; made not by one man, but by 

 a number working independently. Nor was 

 the record confined to one period; it extended 

 throughout the summer, beginning with the 

 first larva? found on the marshes in Jfarch 

 and ending only with the last stragglers late 

 in October. 



It is of some itnixirtance to note that local 

 conditions determine the development of these 

 salt-marsh mosquitoes. All the species (save 

 possibly tiifiritulus) lay their eggs in the mud 

 of the marsh — never in water. Wlienever 

 these eggs become covered with water they 

 hatch, and if there is water enough a brood 

 develops. It may rain at Cape May and not 

 at Atlantic Cit.v, and there has been a fall of 



