CALOPUS A DIUENAL MOSQUITO 263 



After dusk or dark I have only once met with a specimen ; this was a male, feed- 

 ing in a sugar-basin rather before seven p. m. These statements are derived from 

 observations whilst working in the laboratory, and during a residence for a week 

 in the house of a gentleman, whose garden was liberally supplied with ant-guards 

 (perforated troughs filled with water, for preventing the access of the de- 

 structive ' Saiiba ' to the plants), each of which was full of developing larvae and 

 pupae. Sitting in the verandah of this house it was easy to catch fifty to eighty 

 specimens without moving from one's chair, in the early hours of the afternoon, 

 yet after sundown, not a single individual was met with." 



Button, in the malaria expedition to the Gambia, observed calopus and found 

 it strictly diurnal. 



" The observation of Durham and others with regard to Stegomyia fasciata 

 was fully confirmed at Bathurst ; these mosquitoes only bite during the day, more 

 especially in the early part of the afternoon. None of this species were collected 

 in mosquito nets during the night." 



It has been the experience of one of the writers (Howard), sleeping in hotels 

 in the Southern States where the mosquito canopies were faulty, that when other 

 species of mosquitoes were not in the room he was undisturbed until the room 

 was lighted by the rising sun; then Aedes calopus began to bite furiously. Ac- 

 cording to E. G. Hinds, at Victoria, Texas, they seem most active from eight to 

 ten in the morning and from four to six in the afternoon, and are very active 

 just before a storm. 



Carter states that calopus has not been found to feed in the dark nor in a 

 strong light, and that its feeding seems to depend more on the degree of light 

 than on the time of day. He says that if the place be fairly light, it approaches 

 its victim on the shadow side, thus especially attacking the ankles under a 

 writing table, or the hands under the head during a siesta. It does not bite out 

 of doors in ordinary bright daylight. Knowledge of these points is of much 

 practical value. Carter points out that by these habits is explained the com- 

 parative safety of daylight communication with towns infected with yellow 

 fever; that is to say, entering a town only after ten a. m. and leaving by four p. m. 

 under pledge to go in only on sunny days and to enter no residence. The danger 

 of staying all night, he points out, is really the danger of the late afternoon, 

 early evening and morning hours, spent, of course, in houses. 



Veazie, of New Orleans, in an early paper (New Orleans Medical and Surgical 

 Journal, 1901) says that this mosquito " usually flies and bites in the daytime; 

 if a light is burning at night you Avill find an occasional one . . . [It] is quite 

 cunning in selecting the dark side of a person away from the light, and espe- 

 cially likes persons in dark clothing; old people, as they usually sit quiet, are 

 greatly annoyed in the daytime by them." Taylor, of Havana, says of calopus, 

 " If hungry, it will bite freely at any hour of the day or night." 



Charles S. Banks has observed Aedes calopus in the Philippines and says: 

 " It is altogether a day flier, individuals being seen after dark only on the very 

 rarest occasions." 



Goeldi, originally of the opinion that calopus does not bite during the night, 

 was obliged after cumulative instances to admit that it may do so. Writing 



