ANATOMY OF THE MOSQUITO 



367 



The three pairs of legs are attached to the thorax. 



Each leg has 9 parts. The two short ones are the basally placed coxa and the 

 small trochanter attached to it. Then come the long femora, tibia and metatarsi 

 with the four segments of the tarsi terminally. The last tarsal segment ends in two 

 claws, which in the female may be simple or uni-serrated. 



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

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

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

 chitinous processes. 



FIG. 92. Distinguishing characteristics of mosquito larvae and fly antennas 

 Siphon tubes of i, Stegomyia, 2, Culex, 3, Tcsniorhynchus; mental plates of 4, Tcenio- 

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

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



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 

 to dip out large numbers of larvae from the pools and having noted the characteristics 

 of the larvae, to do the same when the pupae develop; so that we have only to verify 

 our identification when the insect emerges from the pupa. 



THE OVA 



The egg raft of Culex, containing about 250 ova, is quite perceptible on the surface 

 of the water as a black, scooped-out mass, about ^ inch in length. The eggs 



