REPORT ON MOSQUITOES. ii 



of the communitv there an iinequaled opportunity for practical 

 and effective work. 



For a month in 1904 Mr. Mellor was again employed, this 

 time to make a rough survey of the territory along the Bay 

 Shore from Dennis Creek to Salem Creek and up the larger 

 streams like the Cohanse}' to determine first, how far up these 

 creeks the salt marsh forms could breed, and second, the general 

 methods that would have to be adopted in dealing with the 

 species in that territory. 



The work done by these gentlemen appears in more detail 

 elsewhere in the report. 



Mr. Henry L. Viereck, of Philadelphia, Pa., was in the service 

 during the summer of 1904, and stationed, most of the time, at 

 Cape May. Excursions were made to shore points further 

 north and to points on the Delaware River ; but the place where 

 the chief work was done was at Cape May. The problems 

 assigned to Mr. Viereck for study were the egg-laying habits 

 of the marsh mosquitoes in greater detail than before known, 

 the length of life of a brood, the number of broods and other 

 facts connected with the species. A series of experiments was 

 also made with several species of pool and ditch fish to determine 

 their effect upon mosquito larvje and their relative value as 

 destroyers. Incidentalh^ the parasitic worm that infests the 

 body of the mosquito was observed and the percentage of infested 

 specimens was determined. 



W'ith these especial points to be determined was associated a 

 survey of the Cape area for breeding places, to determine how 

 the pest could be controlled in the cheapest and most complete 

 manner. 



To ascertain as accurately as possible whether the marsh 

 mosquitoes have a preference as to breeding points, Mr. Viereck 

 studied the marsh itself and its flora, especially where breeding 

 pools were most plentiful. It was found, in brief, that there was 

 some relation between the flora and the abundance of the wrig- 

 glers ; but that the range of breeding places was greater than 

 any one botanical area. 



In general the results were satisfactory and a good collection 

 and series of notes were obtained from which some of the facts 

 stated in this report are derived. 



The question, what use are mosquitoes? is usually answered 

 by a reference to the habits of the larvae, which are said to be 

 scavengers feeding on the micro-organisms that cause foulness 

 in water. Unfortunately wrigglers are often found in the clear- 

 est spring's, and some species never occur in any water that is in 

 the least foul and then onlv in such small numbers that the con- 



