3 o8 



THE MOSQUITOES 



These are of the utmost importance in differentiating mosquitoes and must not 

 be confused with the antennae, which are attached above the palpi and at the sides 

 of the clypeus. These antennae are of importance in distinguishing the sex of the 

 mosquito. 



The thorax is largely made up of the mesothorax, at the posterior margin of 

 which is a small, sharply-defined piece, the scutellum; this may be smooth or trilo- 

 bed. Underneath and posterior to the scutellum is the metanotum; the metano- 

 tum is bare in Culicinae, has hairs in Dendromyinae and scales in Joblotinae. 



There is a pair of wings attached to the posterior part of the mesothorax and, 



FIG. 90. Distinguishing characteristics of mosquito larvae and fly antennae. 

 Siphon tubes of i, Stegomyia, 2, Culex, 3,Tasniorhynchus; mental plates of 4, Taenio- 

 rhynchus, 5, Stegomyia, 6, Culex; larval antenna- of 7, Culex, 8, Stegomyia, 9, Anoph- 

 eles; antennae of 10, Muscidae, n, Tabanidae, 12, Simulidae, 13, Sarcophagidae. 



more posteriorly still, a pair of rudimentary wings (halteres) attached to the 

 metanotum. The three pairs of legs are attached to the thorax. 



There are nine segments in the abdomen. The genitalia arise from the termi- 

 nal segments as bilobed processes. In the male there is a pair of hook-like appen- 

 dages or claspers, between which, and ventrally situated, are the harpes, also a pair 

 of chitinous processes. 



In considering the question of the possible danger which might arise from the 

 introduction of a case of yellow fever, malaria, or filariasis, it would give the greatest 

 information if mosquito ova were at hand so that we could by watching the develop- 

 ment from egg to larva, pupa, and insect, have all the points from which to decide 

 as to the genera developing in the given locality. It is generally a very easy matter 



