250 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loc 



and Blanton, Graham, and Keenan (1955) gave details on efforts to 

 control the enormous population of Culicoides furens (Poey) at Fort 

 Kobbe, which adjoins Farfan swamp on the west bank of the Pacific 

 entrance of the Canal. The most successful measure was the installa- 

 tion of tide gates at the mouth of the Farfan River in August 1950. 

 After the rainy season had passed, by February 1951 , the action of these 

 gates in eliminating salt water from the marshes caused the water level 

 to recede to the deeper ditches and channels. This change resulted 

 in the growth of luxuriant vegetation on the drier ground and a great 

 reduction in the Culicoides population. The tide gates were only of 

 temporary construction, and owing to their gradual deterioration by 

 the end of 1953 the water level in the marsh had risen and the salinity 

 had increased so ih&t jurens again became a serious pest. Airplane 

 spraying of the marshes with dieldrin and lindane at the rate of 1 

 pound and chlordane at 2 pounds per acre gave good control for several 

 weeks, but was too expensive for any but emergency measures. Fog 

 and mist sprays for adult control were almost useless, since the adults 

 emerged in large numbers daily from the marsh during the breeding 

 season. Painting window screens with DDT gave some protection 

 inside houses, but some insects would pass the barrier and bite before 

 the insecticide took effect. 



Methods of Collection and Study 



The primary source of our specimens has been the material obtained 

 by the junior author from surveys for insects of medical importance at 

 military installations in the Republic of Panama and the Canal Zone 

 (Blanton, Galindo, and Peyton, 1955). These surveys were begun in 

 the Canal Zone, but were gradually expanded to take in as large an 

 area of the Republic of Panama as possible. Most of the survej^s 

 were made on the principal road systems of the Republic, but several 

 were made at installations in Darien Province, accessible by boats of 

 the Inter-American Geodetic Survey at Patino Point. A large series 

 of collections was made at Almirante in Bocas del Toro Province in 

 connection with the yellow fever studies carried on by the Gorgas 

 Memorial Laboratory. 



Nearly all our material was obtained by means of New Jersey light 

 traps operated primarily for studies on mosquito distribution. Light 

 traps were operated in about 150 localities (see map in fig. 2 for the 

 principal locations). In each locality it was customary to operate as 

 many as three generators and six or more light traps within a radius 

 that could be serviced by a survey crew of two to eleven men. A 

 Shannon trap was also operated in some areas. This trap is a tentlike 

 enclosure made of cheesecloth or mosquito netting, hung from the four 

 upper corners by tying cord or rope to limbs or trees at a height which 



