402 AGRICULTURAL EXPERIMENT STATION. 



August 3d a flying trip to Ocean City located some of the prin- 

 cipal breeding areas and at Atlantic City it was observed that C. 

 pungens seemed tO' be the most troublesome form at night. 



It was noted that the continuous south winds resulted in a 

 lessening of the numbers of fresh mosquitoes and it was further 

 found that sollicitans w^ould bite readily enough after the eggs 

 were all laid, if a chance was offered. Practically all the gravid 

 females found at this time had remnants of blood food in the 

 alimentary canal, and Mr. Viereck rather concluded that most of 

 these w^ere return migrants that had been inland to feed and came 

 back to the marshes to deposit the maturing eggs. 



August 6th, Mr. Seal joined Mr. Viereck in a systematic col- 

 lection of the small fish found in the tide pools, ditches and chan- 

 nels, the object being to determine whether the top minnow, 

 Gambusia, occurred anywhere in these waters. This little fish 

 is the most ejffective enemy of the species of Anopheles, but un- 

 fortunately no signs of it were found. 



Ditching to drain the mosquito breeding pools on Poverty 

 Beach was begun at about this time, and Mr. Viereck assisted by 

 pointing out the dangerous places and in a manner superintend- 

 ing the work. 



August /th the marriage flight of saUnarius was observed early 

 in the evening and described, and on the 8th the advance guard 

 of the fifth brood of sollicitans was noticed. August 9th it rained, 

 and on the loth there w^as a lively wriggler population in nearly 

 all the new pools. Where fish had been introduced and had sur- 

 vived, they apparently disposed of the larvse as fast as they ap- 

 peared, and so more of the larger pools on Poverty Beach were 

 stocked while the ditching work was carried on. It was also 

 found that in places where the salt hay had been burnt, the pools 

 contained no wrigglers ; so the question arose whether the fire had 

 destroyed the eggs or whether none had been deposited in the 

 charred surface. On the 12th, A. crucians was bred, and its 

 larva positively determined. Experiments were also made with 

 some predatory beetle larvae, which occurred in pools tolerably 

 free from mosquito larv?e and one specimen ate or killed 434 

 wrigglers in less than three days ! 



Another dry spell coming on, pools disappeared rapidly, leav- 

 ing the surface covered with dead wrigglers and over these areas 

 sollicitans and tccniorhynchus were observed in numbers. In a 

 few pools the mud was yet moist when, on the 19th, a shower 

 partly refilled them and gave new life to a few larvae that had been 

 buried for at least twenty-four hours. They seemed none the 

 worse for their experience and pupated normally. A shower on 

 the 20th filled up some salt hay pools on Poverty Beach burnt 



