32 NEW YORK STATE MUSEUM 



semicircular outer envelop of mosquito wire, 18 meshes to the 

 inch, protected on its concave surface by two removable V-shaped 

 sections, each with the edges at the apex of the " V " separated a 

 short distance in much the same way as the ordinary fly trap, and 

 one leading to the other and the second into the trap. The use of 

 two is probably for the purpose of offering greater obstacles to the 

 escape of mosquitoes. 68 This or a similar trap is not only of service 

 in reducing the numbers of mosquitoes in buildings, but is also of 

 value in determining the extent and direction of flight. 



Adult mosquitoes may be destroyed in buildings and other in- 

 closures by fumigation with various materials, such as burning 

 moistened pyrethrum, volatilizing Mimms culicide or camphor 

 phenol (3 ounces to 1000 cubic feet), cresyl (5 grams to 40 cubic 

 feet), or cresol (165 cc. to 2640 cubic feet). 



Among repellants may be mentioned oil of pennyroyal, oil of 

 citronella, oil of peppermint, or a mixture of oil of citronella I 

 ounce, spirits of camphor and oil of cedar .5 ounce. Any of these 

 may be combined in the proportions of a few drops to a half ounce 

 of vaseline or lanolin which will greatly increase their effectiveness, 

 since the grease holds the odor and prevents rapid evaporation. 



BLACK FLIES 



The black flies, 69 or buffalo gnats, are small, stout, black insects 

 about one-tenth of an inch long, some with white-banded legs, 

 which are most easily recognized by their appearance, and in the 

 case of certain bloodthirsty species, such as the buffalo gnat, by 

 their settling upon man and animals in large numbers and drawing 

 blood. These insects are especially likely to establish themselves in 

 an almost continuous row just behind the ears or along the hat 

 band, if a hat is worn. They are particularly abundant and annOy- 

 ing in wooded areas of the Adirondacks, in portions of Minnesota, 

 and in some of the southern states, especially from Tennessee south. 

 They are especially likely to be injurious after floods, and in Mis- 

 sissippi have caused the death of cattle, horses and mules, and in 

 more than one instance imperiled human life. Unsuccessful at- 

 tempts have been made to prove a connection between these insects 

 and the spread of pellegra. 



The greenish or dark-colored gelatinous larvae occur mostly on 

 rocks in comparatively shallow water, frequently forming almost 

 continuous patches with an area of several square feet. The biting 



68 Zetek. Ent. Soc. Amer. Ann., 6:17. 1913. 

 69 Simulium sp. 



