intensity and frequency of these movements vary with the temperature and 

 oxygen contents; the movements become more frequent when the oxygen 

 content falls and vice versa. In the Integripalpia, the "anchor" which holds 

 the moving pupa to a point consists of the dorsal tubercles or ridges of the 

 1st abdominal segment of the pupa, which have been described earlier; 

 the pupa clings to the walls of the case with crotchets and spines. The 

 lateral line of the Integripalpia is covered with a row of dense and long setae 

 which intensifies the current in the tube. 



FIGURE 159. Pupa of Hydropsyche sp.in the cocoon, in the current 

 created by its movements (after Sattler) 



(101) 



FIGURES 160—163. Cleaning apparatus of the pupa: 



160 — head of pupa of Par achiona p ic ic or nis with setae of the labrum; 161 — 

 mandibles and anal rods of the pupae of Leptoceridae: head with mandibles of M yst a - 

 cides longicornis (A), opening of the posterior end of the case of Lep to cerus 

 senilis, cleaned by the anal rods (B); sameof L. a terr im us (C); 162 — Molanna 

 angustata: anterior cover of case with dorsal opening (A); position of the head of the 

 pupa inside the case (B); 163 — Odont ocer um albicorne: position of the head of 

 the pupa (A) when the anterior opening of the case is ventral (B). (All drawings after 

 Thienemann, except 161, C) 



The current of water sucked into the pupal case is rarely free of matter 

 which clogs the openings of the membrane and sieves; the pupa uses its 

 cleaning apparatus to clean the membranes; this apparatus consists of setae 



5724 



92 



