Mosquitoes are week flitirs and usually seek shelter when the wild blows. so that railroad trains, ships and wagons are far more effective than their own wing* in accomplishing their dissemination, . ,`T Notwithstanding2t- the chief human in tersarti'mosciti rises from their bThod siicking habits, yettaste. for blood is cer tainly an an4 a relatively unim 1 portant f id th ives of the majority of mosquitoes. The normal food of both sexes of many species, and the only food of the males of nearly all, consists of the juices of flowers, fruits and other plant parts. In a few species a meal of blood by the female seems requisite to the maturation of the eggs, but this is decidedly exceptional. Most of the species are active chiefly at night, but a few, like Stegomyia fas ciata, in which also both sexes bite, are most vicious during the early afternoon. The bites of all species are not equally irritating, prob ably the result of dissimilar qualities of the salivary secretion which is poured into the wound to facilitate the blood flow. Ammonia and glycerine allay the irritation. Besides the warm-blooded birds and mammals, mosquitoes attack fishes, frogs, turtles and even other in sects.
Until within a few years mosquitoes were regarded merely as intensely annoying pests, but since the definite discovery of their rela tion to disease-transmission their momentous importance has been recognized. Besides sev eral diseases of the lower animals three serious human maladies — malaria, yellow fever and elephantiasis — have been definitely traced to their agency, and they are suspected of others.
Kinds and Characteristics.— Within the limits of North America nine genera and up ward of 30 species are known to occur.
Illustrations are here given of the three va rieties which assume importance through their relations to the human race: the Culex, or gut ter mosquito, The Anopheles, or swamp quito, and the Stegomyta, or cistern mosquito.
Cule.r pungens prefers the gutter and May be faceted to the sparrow among birds: it is noisy and' numerous, and always hungry.
The male *meet (Fig. I) presents a rather bushy head-dress, by which it .may be easily distinguished froM the blainer but more danger ous female. Male, mosquitoes are not blood suckers, but vegetaTians; for the reason that the male insect cannot pierce the skin and must, therefore, subsist on food more easily obtained.
The feeding organ of the mosquito, called the proboscis, is c mposed of seven parts (Fig. 2), which togeth r form the organ by means of which the b ood is reached and through which it is obtained. , In the male insect the stylet, or piercing in strument, is adherent to the neighboring parts and cannot move sufficiently to puncture the skin.
The female insect (Fig. 3) is plain as com pared with the male. The palpi, those projec tions on either side of the central proboscis, are much shorter in the female; and the organs to the outer side, the antennae, are not as beauti fully plumed. The female of the Culex is very
annoying, but is not known to transmit disease in this country, though it is suspected of convey ing dengue fever. In eastern tropical countries a species of the Culex is connected with the dis ease known as elephantiasis.
The Anopheles is the spotted-winged swamp mosquito, responsible for malaria in the human. A peculiarity of this mosquito is its long, thin legs, and the dark spots on the wings are char acteristic. The same general difference in the head-dress of the sexes obtains, save that the palpi are about equally long in both, as may be seen by comparing the pictures (Figs. 4 and 5).
The Stegomyia is for the South by far the most important mosquito; not because it is most numerous, but because it is the natural conveyer of yellow fever. It has been called fected, when the object of his search is directly in front. The song of the insect is not pro duced solely by the buzzing of its wings, but also by the vibration of a peculiarly constructed the tiger mosquito because of its striped ap pearance. It is a most beautifully marked mos quito and very dainty. It is essentially a domestic insect and is found only in inhabited localities. It is a day mosquito, and, resting on a dark background, such as a black coat or dress, presents a particularly striking appear ance, the white bands on the legs and the pecu liar marking of the back easily distinguishing it from any other (Figs. 6 and 6a).
The antenna of all male mosquitoes are more hairy than those of the female. Some of these hairs respond to sound by a vibratory motion; they are, therefore, auditory. These chitinous process situated near the breathing apertures along the sides of the insect and set in motion by respiration. This is the famous yellow fever mosquito, which has been the great est and most persistent enemy the South has ever had, costing many thousands of lives and many millions of dollars, but which is at last, happily, conquered, if we but use the weapons that have been put in our hands by the patient searchers for truth in the field of science.
are the ears of the insect and it is believed that the male flies to the female guided by her song, adjusting the direction of his flight by turning Ins head until both antenna are equally af Mosquitoes cling to surfaces as a cat clings to the bark of a tree. A mosquito cannot rest on a perfectly smooth perpendicular surface; a fly can. A fly's foot is a sucker; a mosquito's foot is a claw (Fig. 7). Mosquitoes resting upon window panes would seem to deny this, but a window pane, very shortly after a thor ough cleaning, may collect enough moisture and dust to form a film over the glass sufficient, though invisible, to afford a firm hold for the insect.