Genitalia. The gonads begin to develop already in young larvae, and 

 the female and male gonads are already clearly developed in larvae in the 



48 middle of their development. In adult larvae close to pupation, the ovaries 

 and testes are rounded or oblong organs in abdominal segments 4 or 5, or 

 extend to intersegmental regions of these segments (Figures 55 and 56). 

 Among the species studied by us, both the female and male gonads of species 

 Phryganea sp.,Anabolia nervosa, A. soror, Limnophilus 

 indivisus, L. affinis are situated in the 5th segment; in L. stigma 

 the testes are situated in the 5th segment, the ovaries in the 4th and 



5th segments; in Platyphylax designatus testes and ovaries are 

 situated in the posterior part of the 4th segment and in the anterior part of 

 the 5th segment; in Rhyacophila s e pt e nt r i o n i s the testes are 

 situated in the 5th segment, the ovaries in the 4th segment (Vorhies, 

 1905:117-118; Lubben, 1907:102-112; Marshall, 1907; Lutman, 1910; 

 Branch, 1922:259-260; Pkhakadze, 1928:193-199).* 



49 The testes consist of tubes or sperm lobes; the testis of caddis flies 

 possesses 5 such tubes (Figures 65 and 66); in mature larvae close to 

 pupation, the cellular elements are zonally arranged (Figure 67); the 

 spermatogonia (A) are at the distal end, the spermatocytes (B) more 

 proximal; at the basal end, closer to the sperm ducts are the spermatids (C); 

 there are spermatocysts (D) in the prepupa, and there is sperm (E) in 

 young pupae. 



50 The ovaries consist of ovarioles covered with an amorphous membrane 

 (Figure 68) divided into a terminal filament, the area of the future egg 

 chambers and the pedicel (Figure 69). The ovarioles of young larvae are 

 broad and short; their cellular elements are little differentiated. The 

 ovarioles become elongated as the larva grows. In mature larvae (Figure 70] 

 the walls of the ovariole are lined with small cells of incompletely 

 developed follicular epithelium; there is no division into egg chambers 

 except in the distal region where the cellular elements form groups which 

 are differentiated into oocytes and nutritive cells. The egg chambers 

 become differentiated later, in young pupae (Figure 71 ); each chamber 

 contains an oocyte and several nutritive cells; the epithelial lining is 

 developed in the basal part of the chamber. The almost mature oocyte and 

 its nutritive cell are illustrated in Figure 72. 



M o ve m ent, r e s pi r at i o n and feeding 



Movement. The main method of movement of the larvae is a slow 

 walk, or creeping (rarely running) on the bottom or on the surface of plants 

 and other objects. 



The free-living predators of the suborder Annulipalpia (e. g., Poly- 

 centropodidae, Hydropsychidae) run rapidly on the bottom or on their nets; 

 their legs are strong, and are of almost equal size. The larvae of 

 Rhyacophila crawl like reptiles, extending the legs laterally and clinging 



* The position of the gonads in the 3rd abdominal segment of the larva as stated by Klapalek (1888:8) has 

 not been confirmed. 



44 



