.4 Caddis -fly 



199 



Fig. 106. End view of pupal case of Limno- 

 philus showing silken barrier; enlarged. 



readier egress from 

 the case; they reach 

 forth from the front 

 end, clutching any 

 solid support. 



The larva of Lim- 

 nophilus lives in the 

 case shown in figure 

 105. This is a dwel- 

 ling composed of flat 

 plant fragments 

 placed edgewise and 

 attached to the out- 

 side of a thin silken 

 tube. 



The larva, living 

 in this tube, clam- 

 bers about over the vegetation, jerkily dragging its 

 cumbrous case along, foraging here and there where 

 softened plant tissues offer, and when disturbed, quickly 

 retreating inside. It frequently makes 

 additions to the front of its case, and 

 casts off fragments from the rear; so 

 it increases the diameter to accom- 

 modate its own growth. 



When fully grown and ready for 

 transformation the larva partially closes 

 the ends, spins across them net-like 

 barriers of silk to keep out intruders 

 while admitting a fresh water supply. 

 Then it molts its last larval skin 

 and transforms into a pupa, of the 

 form shown in the accompanying figure, 

 having large compound eyes, long anten- 

 nae, broad external wing-cases and 

 copious external gills. 



Fig. 107. Pupa of 

 Limnophilus. 



