CULEX QUINQTJEFASCIATUS 355 



intervals for digestion. The males feed on sugar and other s-weet sutstances and 

 are attracted to beer, wine and other liquids. The species thrives only in the 

 vicinity of man. This species is the principal one concerned in the transmis- 

 sion of Filaria hancrofU, which produces filarial disease in man. It is probably 

 the only mosquito to be considered in the control of this disease. Culex quinque- 

 fasciatus is also the transmitter of Dengue fever, a disease of man in wai-mer 

 climates. It is further known as the transmitter of certain malarial parasites 

 peculiar to birds. The males are generally stated to be very short-lived but 

 Goeldi has kept males alive on a diet of honey from 53 to 56 days. 



The distribution of Culex quinqttefasciatus is a tropical and subtropical one, 

 its known range in the United States extending as far north as Washington and 

 St. Louis. It is not known whether the females hibernate at these extremes of 

 its range or whether the species is reintroduced each season. In the southern 

 part of our region it replaces Culex pipiens entirely ; but in intermediate lati- 

 tudes, for instance that of Washington, District of Columbia, the two species 

 occur intermixed in rain-barrels, also associated with Culex restuans and Culex 

 salinarius. In warm summers, and toward the end of the season, Culex quin- 

 quefasciatus predominates in this latitude (Washington), and is the species so 

 troublesome in our parks and houses in August and September. The larvse 

 probably breed in the catch-basins at the corners of the streets. 



In the tropics the adults swarm for mating inside the house. Mr. Schwarz 

 observed the species in Cuba. The swarming occurred in the house, always on 

 the side away from the sun, and when it was almost fully dark. The mosquitoes 

 could be seen only against the sky, when between the observer and the open doors 

 or windows, and close observation was impossible under the circumstances. 

 The swarms comprised both sexes, copulation taking place. A capture of 60 

 specimens from such a swarm contained 44 males and 16 females. 



We translate the following description of the mating habits from Dr. Goeldi's 

 work: 



" The swarms of mosquitoes which one observes at nightfall, entering the 

 house by the windows and filling our rooms with a solemn hum, are to be ex- 

 plained in the same manner [i. e., like the marriage-flights of ants, bees, etc.] ; 

 they are thus celebrating their orgies and bacchanals. It is principally the males 

 which at that time invade the house, united in swarms of 50 to 100 or more in- 

 dividuals, condensed into a compact cloud, in order to find the females which 

 they know or surmise to exist there. Who has not been a spectator of the scene 

 which presents itself when we enter a dark room at the time indicated ? 



" An infernal music of innumerable mosquitoes assails our ears, while at every 

 moment one and another strikes against our face with disgusting and provok- 

 ing impudence. Striking a light we perceive, beyond the luminous area, the 

 impish multitude dancing and cutting frantic capers; there are two clouds, each 

 of which is composed of individuals of only one sex, which, fluttering and de- 

 scribing capricious evolutions, execute, by means of the sound produced by their 

 wings and halteres, an orchestra or recitative chorus dominated by the baton of 

 Eros. 



" Whoever will take the trouble can quickly convince himself that there are 

 two sounds, a higher one and another lower one; the first is produced by the 

 males, the second by the females. . . . 



" They sing because thus the two sexes make themselves known and recognize 

 each other at some distance. Kothing is more destitute of ceremony than sexual 

 union ; some female suddenly disengages herself from her companions and ap- 

 proaches the cloud of dancing males. Immediately she is captured by a male and 

 united the pair recedes from the indiscreet multitude. It is not rare that these 



