OF WASHINGTON, VOLUME XI, 1909 147 



the windows are screened. They bite viciously and are alto- 

 gether disreputable in their behavior. They are widely dis- 

 persed through the shelter of the woods and are very abundant. 



From these considerations it appears that the economic 

 problem of the mosquitoes at Dublin, New Hampshire, is es- 

 senntially concerned with Mansonia perturbans. If the nuisance 

 caused by this mosquito were abated, the summer residents 

 would experience little inconvenience from mosquitoes, at least 

 in their residences, and the prosperity of the place would be 

 promoted by the influx of newcomers. 



An institution called the Dublin Chemical and Pathological 

 Laboratory is maintained by the summer residents for the con- 

 servation of healthful conditions in the community. It is in 

 charge of Dr. E. C. Stowell, of Boston. Dr. Stowell has been 

 much interested in the mosquito problem, and has left no stone 

 unturned to discover the breeding places of Mansonia pertur- 

 hans, not only by personal effort, but by inviting examination 

 by all the leading American students of mosquitoes. The 

 writer first visited Dublin in August of 1908 at Dr. Stowell's 

 invitation and made a cursory examination of the territory. 

 In the spring of 1909 he made a visit of a few days in company 

 with Mr. A. N. Caudell with the intention of making a complete 

 survey, but the season proved to be not far enough advanced 

 and the survey was abandoned. Later Mr. A. Busck was sent 

 there and made extensive studies on the occurrence and specific 

 identity of the woods species. In none of this work, nor at 

 the visits of other entomologists, nor by the labors of Dr. 

 Stowell and his able assistant, Mr. Howe, were any breeding 

 places of Mansonia perturbans discovered. The breeding- 

 habits of this species are peculiar. Fortunately they are now 

 known, through the timely discovery by Mr. J. T. B'rakeley at 

 Lahaway, Xew Jersey. Unlike all other mosquito larvae, those 

 of Mansonia perturbans remain all winter in the mud at the 

 bottom of suitable ponds, attached by their air-tubes to the 

 vascular roots of certain species of grass. But few ponds 

 present suitable conditions, so that the supply of these mosqui- 

 toes in an *iven region generally comes from but a single 

 source. TT is source is not always easy to discover. The 

 writer made a third visit to Dublin in August, 1909, and was 

 able to discover an extensive breeding place of the species. 

 I'ossibly this is not the only source of the supply of these 

 insects, but it seems to be the only place in which they breed at 

 present in numbers in the immediate vicinity of Dublin. 



