838 MOSQUITOES OF NORTH AMERICA 



light. In cool, rainy weather it remains quiescent in its retreats in dark corners 

 or upon dark clothing. For these latter it has a special predilection as a rest- 

 ing place. 



Copulation occurs in warm weather during the hot, sunny hours of the day. 

 According to Goeldi the males congregate in little swarms of 15 to 20 or more, 

 hovering over the edge of a table, cabinet or other object, or over a person. When 

 a female approaches one of these little swarms it is pounced upon by a male. 

 Copulation is effected during flight, the male clasping the female from beneath, 

 and is quickly accomplished. The flight is so short that, according to Goeldi, 

 copulation is easily effected in a breeding-cage. 



The eggs develop best after having remained dry for a period. When in con- 

 tact vrith water or submerged they develop rapidly under high temperatures. 

 According to Peryassu the eggs hatch regularly at temperatures from 25 to 

 29 C. ( = 77 to 84 F.) and all the eggs deposited at one time hatch together. 

 At these temperatures the time of hatching is from 3 to 8 days. Below 25 C. 

 (77 F.) only part of the eggs hatch and these irregularly. A fall of tempera- 

 ture to 20 C. (68 F.) for even a single night either retards hatching or pre- 

 vents it. Low temperatures have a decidedly bad eifect upon the development 

 of the larvae. 



These facts stand in intimate relation to the distributions of the species. It 

 is found established only in territory with more or less uniformly high tempera- 

 tures. In the more temperate regions it is frequently introduced during the 

 warmer season by traffic from farther south and then exterminated by the cold 

 winter weather. This is the case, for example, in the southerly part of the 

 United States, where the species is endemic only below the frost line. Owing to 

 its close association with man it is often carried by vessels and railroads and thus 

 temporarily established far to the north of its permanent habitat. In Europe 

 it has been found as far north as England and in America it must have once 

 found a foothold in Boston, Massachusetts, as a considerable epidemic of yellow 

 fever occurred there. A full discussion of the habits will be found in volume 

 one of this work, pages 258 to 303. 



Endemic in tropical regions of both hemispheres, seasonally introduced in 

 temperate regions. 



Washington, District of Columbia, July 3, 1901 (J. Carroll) ; August 28, 

 1908 (R. W. Van Horn) ; Norfolk, Virginia (R. Blue) ; Virginia Beach, Vir- 

 ginia, August 25, 1900 (F, C, Pratt) ; Columbia, South Carolina, September 12, 

 1908 (W. H. Sligh); Thomasville, Georgia, October, 1905 (W. W. Jarrell) ; 

 Myrtle, Georgia, September 1, 1906 (A. A. Girault) ; Fort Valley, Georgia (J. 

 H. Beattie) ; Savannah, Georgia, August 8, 1901 (T. E. Oertel) ; St. Louis, 

 Missouri, August to October, 1904 (A. Busck) ; Memphis, Tennessee, July 29, 

 1904 (H. S. Barber) ; Tuscumbia, Alabama, August 15, 1904 (H. S. Barber) ; 

 Richmond, Kentucky, August 25, 1904 (H. S. Barber) ; Lexington, Kentucky, 

 October 19, 1901 (A. M. Miller) ; Nashville, Tennessee, August 17, 1904 (H. 

 S. Barber) ; Columbia, Tennessee, August 16, 1904 (H. S. Barber) ; Athens, 

 Tennessee August 22, 1904 (H. S. Barber) ; Chattanooga, Tennessee, August 

 20, 1904 (H. S. Barber) ; Decherd, Tennessee, August 18, 1904 (H. S. 

 Barber) ; Scott, Arkansas, September 1, 1908 (J. K. Thibault, Jr.) ; Hot 

 Springs, Arkansas, October 1, 1900 (A. Wright) ; Baton Rouge, Louisiana (J. 

 W. Dupree) ; New Orleans, Louisiana, September 21, 1900 (H. A. Veazie) ; 

 Napoleonville, Louisiana, November 7, 1900 (L. E. Flannagan) ; Belzona, 

 Mississippi, August 5, 1904 (H. S. Barber) ; Westpoint, Mississippi, August 

 11, 1904 (H. S. Barber) ; Helena, Arkansas, July 30, 1904 (H. S. Barber) ; 

 Jackson, Mississippi, August 7, 1904 (H. S. Barber) ; Winona, Mississippi, 



