CADDIS-FLIES (PHRYGANEID^). 287 



Caddis-flies (Phryganeid^). 



Caddis-flies, "Water-moths, or Trichoptera, are Neuroptera 

 that are aquatic during their larval life. The adults resemble 

 moths ill appearance ; but the wings are not scaly, and are 

 turned down at the sides of the body when at rest. They are 

 more or less covered with hairs, and the cross- veins are much 

 fewer than in most Neuroptera; legs and antennae are long, 

 and their mouth-parts are but poorly developed. The eggs 

 are laid in gelatinous masses upon water-plants. The larvae, 

 which are often extremely injurious to water-cress, live in curi- 

 ous cases made up of stones, shells, pieces of wood, &c. The 

 Caddis-worms are long cylindrical larva; with scaly heads and 

 strong jaws ; the three segments near the head are leathery, and 

 each bears a pair of legs. The front part of the larva alone 

 sticks out of the case when moving, the other nine segments 

 being enclosed in the curious larval covering. The tail has two 

 hooks by which the insect anchors itself to a stone or plant 

 in the water. Some species reach nearly an inch in length. 

 The pupal stage is passed in the case, the pupa emerging a short 

 time previous to the advent of the adult, and crawling up to the 

 surface of the water, ready to escape. There are a great number 

 of species ; but the most abundant in the water-cress beds is 

 LimnepMlus Jfavironiis, which has a wing-expanse of one and 

 a quarter inch. 



Prevention and Remedies consist in draining off the beds and 

 clearing out all the plants, leaving the beds to dry for some 

 weeks previous to winter planting. Birds, especially sparrows, 

 clear the insects off, and do much good. When present in 

 numbers, a good plan is to fill the beds full of water and move 

 the tops of the plants about with poles and rakes to shake the 

 worms off : they then float to the top, and are run off with the 

 excess of water. 



