A Caddis -fly 



199 



Fig. 106. End view of pupal case of Limnr)- 

 philus showing silken 1)arrier; enlarged. 



readier egress from 

 the case; they reach 

 forth from the front 

 end, chitching any 

 soHd support. 



The larva of Lim- 

 nophihis hvos in the 

 case shown in figure 

 105. This is a dwel- 

 hng composed of fiat 

 plant fragments 

 placed edgewise and 

 attaelied to tlie out- 

 side of a thin silken 

 tube. 



The larva, livuig 

 in this tube, clam- 

 bers about over the vegetation, jerkily draggint^ its 

 cumbrous case along, foraging here and theri_' ^^'here 

 softened plant tissues offer, and when disturlied, 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 full}." 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 externa] gills. 



Fig. 107. V\\\y.\ of 

 Limnophilus. 



