1. Conditions in 1916. The mosquito problem is of importance from two distinct standpoints, in relation, respectively, to health and to comfort. The presence of Anopheles mosquitoes which breed in fresh water marshes and sluggish streams is a constant menace to health, since these mosquitoes may be carriers of the parasite of malaria; while various other species of mosquitoes, belonging to the genera Culex and Aedes render life miserable even though they do not cause illness.

When we made our first survey in 1916, both salt and fresh water marshlands in West Haven, along the West River, Mill River and the Quinnipiac and in East Haven were causing a gross mosquito nuisance and the fresh water areas were breeding enough Anopheles mosquitoes to create a very considerable malaria problem. By a very partial canvass of physicians we obtained records of 86 cases of malaria seen during the year 1916, most of them located in the neighborhood of West River, Beaver Swamp, Mill River and the Quinnipiac.

2. Progress During the Past Ten Years. Systematic attempts to control mosquito breeding were begun by the Civic Federation of New Haven in 1912 and greatly stimulated by a law passed in 1915 which gave the director of the Connecticut Agricultural Experiment Station power to make rules and orders concerning the elimination of mosquitoes and mosquito breeding places or areas and to survey, drain, fill or otherwise eliminate any such breeding places, funds for the purpose being provided locally. When the drainage operation is once accepted the State is responsible for its upkeep.

As a result of this legislation, many of the worst breeding places within the city of New Haven and in West Haven have been abolished including all the major Anopheles areas. The decrease in malaria which has ensued is well indicated by the table below which, though it covers only the cases admitted to one hospital, is typical of the general improvement.

CASES OF MALARIA ADMITTED TO NEW HAVEN HOSPITAL.

Of the 14 cases admitted during the years 1921-23, 2 were from Hamden, 2 from West Haven, 2 from the Beaver Swamp region, 1 from near West River, 1 from near Mill River, 4 from the vicinity of the railroad station and 2 from the center of the city. Of the two cases admitted since 1923, one was from Hamden and one from the neighborhood of Edgewood Park (one of the few localities where Anopheles mosquitoes have still been occasionally found in recent years).

3. Results of 1927 Survey. During the summer of 1927 the City Health Department had a systematic survey made of the entire city from the standpoint of mosquito breeding (by Dr. A. F. Dolloff and Mr. R. F. Hart) with the following general results.

The survey of larval breeding places included all of the marshes in, and adjacent to, the city and about one half of the yards and lots, selected as typical of the rest. In addition night catches of adult mosquitoes were made in various parts of the city and the particular species identified.

The collection of adult mosquitoes showed salt marsh species to be predominant in June and early July while later catches showed an excess of fresh water types. The unusually rainy season was no doubt, however, in part responsible for this latter result. Anopheles mosquitoes were found but once in the night catches as compared with 76 salt marsh forms and 128 fresh water forms other than Anopheles. Fourteen locations were found, however, in which Anopheles species were either breeding or were caught near the breeding place but in only four instances was Anopheles Quadrimaculatus (the chief malaria carrier) identified.

In considering the general problem of mosquito breeding in New Haven it is obvious that there are three primary areas to be considered, the low lands adjoining the beds of the three streams which intersect the town, West River, Mill River and the Quinnipiac. In addition there are well defined marshy areas on the east shore of the harbor.

Mosquito breeding in the Beaver Swamp area (tributary to West River), once a prolific source of malarial mosquitoes, has been practically abolished by drainage operations and great improvements have been made in the Quinnipiac and in the east shore salt marsh areas. The chief marshlands breeding mosquitoes in 1927 were as follows (proceeding in each area from south to north).

* This area was drained last fall subsequent to the 1927 survey.

It is obvious from the above analysis that the marshland mosquito breeding problems of New Haven are essentially three in number, the large salt marsh area in the Quinnipiac valley, west of Little River, a series of small fresh and salt water breeding places along the West River valley and a series of rather more important breeding places on the east shore of the harbor.

In addition to these marshy and swampy areas there are in many sections small local depressions which are listed in Dr. Dolloff's report and which should be filled or treated with larvicides during the breeding season. Furthermore, much breeding takes place in tubs, barrels, cans and other receptacles in back yards capable of holding standing water. Out of 370 blocks carefully inspected 193 revealed breeding places of this kind. Ponds were found to be of little significance on account of the fact that most of them contain fish which destroy the larvae.

4. The Present Drainage Program. The Chamber of Commerce of New Haven early in 1927 organized a Committee on Mosquito Elimination which, on the basis of surveys made by the Connecticut Agricultural Experiment Station, has formulated a comprehensive program for the elimination of the chief remaining salt marsh mosquito breeding areas in and around New Haven. This program includes three major projects, as follows, covering all the important salt marsh areas not drained in 1912-16.

(1.) Quinnipiac Marsh. Ditching of 310 acres in North Haven and of 571 acres in Hamden and the construction of a tide gate at Middletown Avenue.

(2.) Morris Creek and East Haven. Dredging of Morris Creek, ditching of 514 acres in East Haven and 75 acres in New Haven.

(3.) Branford. Ditching of 317 acres.

The cost of this program was originally estimated at $25,000 but will, it is now believed, amount to $40,000. The city of New Haven and the towns of East Haven and Branford have made appropriations for this purpose and the Chamber has raised a considerable sum by private subscription so that the completion of the bulk of this work seems reasonably assured. It will be carried out in 1928 under the direction of Dr. W. E. Britton, State Entomologist and Mr. R. C. Botsford, Deputy in Charge of Mosquito Elimination of the Connecticut Experiment Station.

5. Summary and Recommendations. New Haven has made encouraging progress during the past ten years in the solution of the unusually serious mosquito problem, created by the fact that the city is transversed by three valleys of low-lying land peculiarly liable to the accumulation of stagnant water. The breeding of Anopheles mosquitoes has been reduced to so low a level that malaria has now ceased to be endemic in New Haven as it was up to 1920. With the completion of the admirable program of the Chamber of Commerce the chief sources of mosquito breeding adjacent to the city will be eliminated.

It must be pointed out, however, that even when all this is accomplished two more things remain to be done.

In the first place the salt marsh areas to be drained under the Chamber of Commerce program must be constantly supervised and the ditches kept clear. The growth of grasses and weeds which obstruct the flow of water soon cause a ditch to be worse than useless, since it itself then becomes a prolific breeding place. It is the duty of the State under the law to maintain all accepted drainage projects but it is essential that the Agricultural Experiment Station should be provided with adequate funds to do this work.

Furthermore the completion of all possible salt marsh drainage operations (with which, alone, the Chamber of Commerce program deals) will still leave the problem of breeding in fresh water swamps, in temporary depressions of land and in miscellaneous receptacles untouched. When it is realized that the 1927 survey located 15 important fresh water swamps breeding mosquitoes within the city and revealed mosquito breeding receptacles in 193 out of 370 city blocks inspected, or more than 50 per cent, one may gain some idea of the magnitude of the problem.

The law is clear on this point. A state statute declares "any accumulation of water in which mosquitoes are breeding" to be a public nuisance and makes it the duty of the Health Officer to cause such accumulation of water "to be abolished, screened or treated in such manner as to prevent the breeding of mosquitoes." The actual expense of dealing with the breeding places found in the course of the Dolloff survey either by draining, filling or treatment by larvicides would be small; but results cannot be attained without the provision of special inspectors to see that the work is performed, unless the present inspectors of the department can be freed from a part of their present duties as suggested in a later chapter. If these fresh breeding places are not cared for, the elimination of the salt marsh breeding places will only arouse hopes which are doomed to disappointment since, as we have seen the fresh water mosquitoes were, last summer at least, far more numerous in the city than the salt marsh varieties.

We would therefore urge, in order that the admirable Chamber of Commerce campaign may produce its full results as

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