REPORT ON MOSQUITOES. 209 



marsh, and while it was plowed and planted like the rest, a pool 

 which formed in that marsh corner contained sollicifans larvae 

 while none were found in apparently much more attractive places 

 away from the direct salt marsh influence. Where a shore town 

 has been laid out with streets and avenues running in all directions 

 through a salt area, the depressions between the streets retain 

 their salt character and will breed sollicitans whenever water 

 gathers, though they may be dry from June ist to December ist. 

 I have in mind several places of this kind which become water 

 covered in winter only, remain water covered until late in May 

 or early in June and mature a brood composed of practically all 

 the eggs that were laid on that place during the preceding season. 

 There is no water from Jmie ist or thereabouts until frost; but 

 mosquitoes are always there and eggs are laid freely. 



On the other hand, once out of the immediate influence of the 

 marsh, neither eggs nor larvae are found, no matter how abundant 

 the adults may be. This is a point which I have tested and had 

 tested again and again, every one of my assistants having col- 

 lected within the range of sollicitans from the salt marsh to the 

 inland, and all having had exactly the same results, whether they 

 collected blindly on definite instructions, or intelligently, with a 

 direct knowledge of the point they were detailed to clear up. 



Mr. Viereck's collections and notes are especiall}^ valuable on 

 this point, for the Cape May Peninsula is comparatively narrow, 

 is thoroughly dominated by sollicitans and was explored in almost 

 every section. The net results of Mr. Viereck's collections is 

 exactly that of all others who have done similar work. There is 

 no breeding away from the salt marsh region broadly considered. 



It is not necessary that there should be any considerable depth 

 to the mud in which the eggs are laid. I have never found 

 larvae in pools with a clear sandy bottom ; but I have found them 

 in grassy depressions among the sand hills, where there was just 

 a scum of the organic mud deposit on the surface. 



Description of t/ie Larja. 



The larva and details are illustrated at fig. 61. When full 

 grown, it is from 8-9 mm., or .32-36 of an inch, in length. It 

 is a large, robust wriggler, dirty gray in color as a rule, but often 

 yellowish white. The head is small in comparison to the body. 

 one and one-half times as broad as long, and yellow in color. 

 The sides and base are shaded with reddish brown and the vertex, 

 though immaculate, generally has lateral blotches and is often 

 clouded in front (see fig. 60, 4, 5 and 6.). A dark clouded 

 14 MO 



