MOSQUITO INVESTIGATION IN NEW JERSEY. 283 



The two troublesome species are Culex sollicitans and C. cantator. 

 A third species, C. tamiorliynchus is also a migrant, but occurs in much 

 smaller numbers and does not fly so far. The fourth, C. salinarius 

 does not seem to migrate. Except the last, all these species lay their 

 eggs singly in the marsh mud, not in water, and these eggs will main- 

 tain their vitality for months during the summer and remain un- 

 hatched during the winter. But when they become covered in summer 

 by a spring tide or a heavy rain they hatch within an hour or two, 

 and millions of wrigglers will be found on a marsh after a storm, 

 where none were seen the day before. In a week these wrigglers are 

 ready for the change to pupa and adult. After the adults have 

 hatched, the first warm sultry night sends swarms numbering millions 

 over the surrounding country. Few of these ever get back and none 

 that leave the marsh finally ever reproduce their kind. In C. sollicitans 

 only the females migrate and all those that were examined proved 

 sterile; the migratory instinct replaces the desire to multiply. In 

 C. cantator both sexes fly; but the males drop out after a few miles 

 have been covered, and the females are sterile as a rule; a few excep- 

 tions have been found. 



It might seem that having said so much, I had placed the problem 

 of control beyond reasonable hope of practical solution; but the 

 statements are yet incomplete and were left so to bring out forcibly 

 the fact that it is no local matter : it is one with which the state must 

 deal comprehensively. In truth not ten per cent, of that vast marsh 

 area breeds mosquitoes at any time, and even a breeding area is not 

 uniformly bad. The mosquito demands water free from fish or 

 predatory insects of all kinds, that shall remain for at least a week. 

 As a rule wherever tides go, the little species of Fundulus or ' killifish ' 

 will go and where they go no wrigglers can exist. Wherever fiddler 

 crabs inhabit a marsh area, and there are thousands of acres so in- 

 habited, their holes drain it completely and afford no chance to breed. 

 It is usually at the edge of the highland, where the tide water works 

 in through grass so dense that it bars fish and fills depressions, that 

 the mosquitoes get their best chance and in a number of surveyed 

 areas it was only the edge of the marsh that was reported dangerous. 

 Other danger spots are the irregular, rather high marshes rarely cov- 

 ered by tides, which dry out completely at times, killing all aquatic 

 life, and then fill all depressions by a heavy storm. Cat-tail marshes 

 when they are at all dense are safe from mosquito breeding. 



A very thorough survey of the entire salt marsh area determined 

 that not over ten per cent, of it is at all dangerous, and the question 

 arose, what can be done to make that portion safe. Of course any 

 scheme that provided for the reclamation of the marshes and made 

 them available for agricultural or other industrial purposes would also 



