Tired of ads and lack of privacy on the internet? Try the new approach by clicking here and downloading Brave, the browser that respects your privacy.

15/17
Home / Albums / Keyword Insect /

Diagram of a longitudinal section of a mosquito

Diagram of a longitudinal section of a mosquito.jpg  Normal position of the larvæ of Culex and Anopheles in the waterThumbnailsLouse of the Cat Normal position of the larvæ of Culex and Anopheles in the waterThumbnailsLouse of the Cat Normal position of the larvæ of Culex and Anopheles in the waterThumbnailsLouse of the Cat

It is well known that mosquitoes, when they bite, inject into the wound a minute quantity of poison. The effect of this varies according to the species of mosquito and also depends very much on the susceptibility of the individual. Soon after the bite a sensation of itching is noticed and often a wheal, or eminence, is produced on the skin, which may increase to a considerable swelling. The scratching which is induced may cause a secondary infection and thus lead to serious results. Some people seem to acquire an immunity against the poison.

The purpose of this irritating fluid may be, as Reaumur suggested, to prevent the coagulation of the blood and thus not only to cause it to flow freely when the insect bites but to prevent its rapid coagulation in the stomach. Obviously, it is not developed as a protective fluid, and its presence subjects the group to the additional handicap of the vengeance of man.

As to the origin of the poison, there has been little question, until recent years, that it was a secretion from the salivary glands. Macloskie (1888) showed that each gland is subdivided into three lobes, the middle of which differs from the others in having evenly granulated contents and staining more deeply than the others.

Author
Handbook of Medical Entomology
By William Albert Riley and Oskar Augustus Johanssen
Published in 1915
Available from gutenberg.org
Keywords
Insect
Visits
128