CALOPUS A DIURNAL MOSQUITO 263 
After dusk or dark I have only once met with a specimen ; this was a male, feed- 
ing 1n 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 ‘ Satiba ’ to the plants), each of which was full of developing larve and 
pupe. 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.” 
Dutton, 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 Aédes 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 will 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, 
“Tf hungry, it will bite freely at any hour of the day or night.” 
Charles S. Banks has observed Aédes 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 
