NO. 8 ANATOMICAL LIFE OF THE MOSQUITO SNODGRASS Jl 



adult. From the base of each lobe inside the pupal cuticle, as de- 

 scribed by Christophers, is cut off a small median lobe (fig. 28 B, 

 Mmr), and the lateral part becomes the rudiment of the clasper 

 (Pmr). Finally, the two median lobes unite around the gonopore 

 to form the aedeagus (C, Aed), while the lateral parameral lobes 

 elongate to become the two-segmented claspers of the adult (D,E). 



In the mature condition the genitalia take on a great variety of 

 forms and are complicated by the development of accessory parts. 

 All this is a great boon to taxonomists, but it often creates difficulty 

 for the morphologist. Anopheles quadrimaculatus (fig. 28 D) gives 

 a good example of one type of structure. Each paramere is divided 

 into a large basimere (Bmr) and a long slender telomere (Tmr). 

 The telomere is movable on the basimere by strong antagonistic 

 muscles arising in the latter. The slender aedeagus (Aed) lies between 

 the bases of the parameres and is connected with the basimeres by a 

 pair of small basal plates (bp). The basimeres are equipped with 

 long spines, and proximally each bears a membranous median lobe 

 (clsp) united with the one from the opposite side. Each lobe is armed 

 with strong spines and is known as a claspette, or claspette lobe. In 

 other genera the claspettes are more commonly independent ap- 

 pendages of the parameres, as seen in Aedes (E). The claspettes, 

 according to Christophers (1922), are cut out from the parameres 

 by secondary incisions of the latter. 



For illustrations of generic and specific variations in the male 

 genital structure the student must consult taxonomic papers, but the 

 nomenclature will be confusing. In the current terminology of 

 mosquito specialists, the aedeagus is called the "mesosome" or "phallo- 

 some," the basal plates (bp) that connect it with the claspers are the 

 "parameres," and the claspers are the "side pieces." In this scheme 

 the term "paramere" is entirely misapplied, since it was first given to 

 the claspers, and moreover, "side piece" is a direct English translation 

 of "paramere." The segments of the claspers are known also as the 

 "basistyles" and "dististyles," but as shown by their development the 

 claspers have no relation whatever to legs or abdominal styli. The 

 terminology given on figure 28 is recommended for its simplicity and 

 because it can be applied, on the basis of development, to the male 

 genitalia in all the principal orders of insects (see Snodgrass, 1957). 



The terminal parts of the female abdomen are much simpler than 

 those of the male, but their homologies are more difficult to under- 

 stand. Beyond the eighth segment projects a small lobe (fig. 27 I) 

 representing the combined ninth and tenth segments. The dorsum of 



