A HANDBOOK 



OF THE 



GNATS OR MOSQUITOES 



PART [.—GENERAL. 

 CHAPTEE I. 



On the Position and Terminology of the Culicidae. 



Without entering into minute detail, it may be well to 

 premise that the CuUcidcB belong to the Order of Diptera, 

 or two-winged insects, in which the hinder of the two pairs 

 of wings of the typical insect are absent as such, and are 

 represented only by a pair of small club-like bodies, the 

 halteres or balancers. All the members of this Order 

 undergo a complete metamorphosis, i.e., they are hatched 

 as worm-like larvce, and after attaining, as to size, if not as 

 to form, the dimensions of the adult insect, and under- 

 going several changes of skin, they cease to eat, undergo 

 profound anatomical changes, and become nymphs or puptz, 

 and, finally, by a last change of skin, they emerge from the 

 pupa case as the externally entirely different imago, or 

 adult insect. 



The Diptera are divided into two Sub-orders, the Orthor- 

 7-hapha and the Cyclorrhapha, according to the method by 

 which the pupae escape from the larval skin. In the former, 

 the rupture is in the form of a T-shaped rent, and the larva 

 is " encephalous," i.e., has a more or less perfectly developed 

 chitinous head ; in the latter, the pupae escape by a circular 

 opening and the larva has no definitely separated anterior 

 division of the body, formed by the blended cephalic somites, 

 1 



