(Rhy a c o ph i 1 a). The lateral margins of the femur bear two inward 

 directed pointed tubercles dorsodistally: the posterior tubercle forms the 

 tibiofemoral articulation, entering into the pit of the basal margin of the 

 tibia. The femur bears 6 primary setae: 2 dorsal (one basal and one 

 distal); the latter is situated slightly posteriorly; 2 ventral setae in a row 

 (at some distance from each other); 2 surface setae (an anterior and a 

 posterior seta) which are usually situated apically or subapically. The 

 primary setae of the femur may be long. 



The tibia is straight or slightly curved and is usually shorter and 

 narrower than the femur; however, the tibia may be as long as the femur or 

 longer, e. g., in the hind legs of Beraeidae, some Leptoceridae and Seri- 

 costomatidae. The convex rib of the dorsodistal margin of the tibia enters 

 into the groove at the basal margin of the tarsus, however, the angle between 

 tibia and tarsus is very small. The tibia bears 6 primary setae, 2 dorsal, 

 2 ventral and one anterior and one posterior seta; all setae of the tibia are 

 25 concentrated in its distal part, often near the distal margin of the leg; the 

 anterior and posterior setae are usually displaced toward the dorsal setae, 

 rarely toward the ventral setae, or one is displaced toward the dorsal setae 

 and the other toward the ventral setae; the dorsal setae are usually situated 

 apically or subapically, but they are sometimes more or less displaced from 

 the margin. 



The tarsus is narrower and shorter than the tibia; its articulation with 

 the claw resembles that between tibia and tarsus. The tarsus bears 

 4 primary setae apically or subapically; the setae are usually arranged in 

 pairs, 2 dorsally and 2 ventrally or subventrally; the ventral setae are far 

 from the dorsal ones but are rarely situated close to them (hind legs of 

 Beraea, S e r i c o s t om a). 



The claws are curved and pointed; the claws of first-instar larvae are 

 slightly curved, those of full-grown larvae strongly or slightly curved; the 

 claw is thickened; there is one primary seta basoventrally, usually in the 

 form of a short and thick spine. 



The length and shape of the primary setae of the legs of the caddis fly 

 larvae vary markedly; some setae may be very short and thick, forming 

 spines. Secondary setae (if present) may develop on all segments of the 

 legs except on the pretarsus; they are often present in large numbers 

 and are markedly differentiated. 



The abdomen is long, consisting of nine soft, membranous, weakly 

 sclerotized segments. The constrictions between the segments are always 

 distinct. In the free-living, very mobile larvae of Annulipalpia, the abdomen 

 is usually slightly flattened and the constrictions between the segments 

 are deep; this is also the case to some extent in the suberuciform larvae 

 of Phryganeidae and Molannidae with tubular cases; in the typical eruciform 

 larvae of the other Integripalpia, the abdomen is almost cylindrical and the 

 intersegmental constrictions are shallow; in some groups (genus Lepto- 

 c e r u s, all Apataniinae, Goeridae, Brachycentridae) the abdomen is short; 

 it is laterally compressed in Hydroptilidae (Annulipalpia). 



In larvae inhabiting tubes (integripalpia) the first abdominal segment 

 bears short, papilliform, thin-walled tubercles dorsally and on the sides; 

 when the larva presses against the wall of the case, these tubercles enable 

 it to perform undulating movements which create a current inside the tube. 



21 



