REPORT ON MOvSOUITOES. 435 



this is not very active in the work of mosquito extermination. I did not 

 pace the amount ot ditching necessary in section (D), 1)ut judging from the 

 marshes I did pace I would estimate that there are ahoul 15,000 feet of 

 staking done. The proposition at North Beach Haven is one of ditching. 

 To the inexperienced eye, the territory at a dry season would appear very 

 harmless. Ihe grass would he dry. The mud holes dry, and even larger 

 pools heing dry might argue that the place was in a safe condition and that 

 no staking was necessary. But if the territory was visited a few days after 

 a rain, the conditions would be greatly changed. Pools, both small and large, 

 would be found everywhere. Larvse would be abundant. Still a few days 

 more and a very uncomfortable flight of mosquitoes comes from this inno- 

 cent looking territory. When we hrst visited this territory (D) the condi- 

 tions of dry weather prevailed. We found adult mosquitoes in the grass but 

 very little water and no larvae. We naturally judged that the adults were 

 froiii a former crop. When we began laying the stakes some rain had 

 fallen. The holes were filled with water. The larvae appeared in great 

 abundance, and when we were finishing the staking the work was done with 

 the greatest discomfort because of the mosquitoes which had issued from the 

 pools, and in many places we saw patches of the insect w^hich had not yet 

 left their native pools. If the ditches which have been laid out are dug, 

 and dug with proper depth and are left clean, the pools which are formed 

 with every rain will pass off before any breeding can be complete ; that 

 is, before the larvc'e can mature. Of course, it is plain to any one that if 

 the mosquito gets no further than the larval stage we are satisfied, for in 

 that case there will be no mosquito from such a source. The presence of 

 water for two or three days is not a matter of great concern, for in that 

 time larvae would be the advanced stage of the breeding, and if the water 

 were to pass off the larvae die and the end of the breeding has come. Thus 

 since the ditches laid out in section (D) will take off the water accumulated 

 by the fall of rain or by a possible high tide, in a few days (two or three 

 days) the breeding in that territory must cease, when the ditches are dug. 

 Along the railroad, near section (D), there are choked ditches. These were 

 built for drainage purposes, but they have lost their use. They are choked 

 with a growth of grass and should be cleaned out. The outlet of the 

 ditches along the line of the railroad is a ditch through section (D), but 

 this outlet ditch has lost its flow by the growth of grass. The railroad 

 , ditches are dug wider and shallower than those dug for the purpose of 

 mosquito extermination and are more readily choked with weed growth. 

 A sluice box should be put under the railroad at the northern boundary of 

 Beach Haven to make an opening for a ditch which should be dug parallel 

 to the boundary and a few feet south of it. 



During the second (August) trip to Beach Haven I spent a day at Spray 

 Beach. Between Twenty-third and Twenty-fourth Streets, near the railroad, 

 I found several small pools on the graded territory, in which breeding was 

 going on. These could easily be filled in. At the junction of Beach Avenue 

 and the northern limit of Spray Beach there was a bad pool. This should 

 be filled. Near the railroad and the northern limit were some bad places. 

 These could be ditched or filled with slight expense. If these few places 

 were filled Spray Beach proper w^ould have no breeding area. North of 

 Spray Beach and near the bay there is a bad strip of territory. It is on 

 the Newbold Estate. The estate has about forty claimants, about five of 

 whom visit the property as a summer home. Nothing has been done on this 

 I^roperty in the way of staking since no immediate ditching was expected. 

 Something should be done on the estate. A dilch under the railroad would 

 be necessary at the southwest corner of the estate, the position of the sluice 

 box being marked on the sketch. 



On the ocean side the breeding places arc located on the Beach Haven 

 property. They are found in the section marked (F). The territory con- 

 sists of sand hills and intervening places which retain water. These pools 

 could easily be filled with the use of a drag. The material is close at hand. 

 The sand hills and pools are very close together. The breeding in these 

 pools was constant and alnmdant. At the corner of Beach Avenue and 



