78 



AN ECONOMIC ENTOMOLOGY. 



than the second, which are folded beneath them. Both wings 

 have numerous longitudinal veins connected by only a few cross- 

 veins, losing the reticulated appearance of the more typical Neu- 

 roptera, and resembling more closely some of the lower moths, 

 for which, indeed, some of the smaller forms may be easily mis- 

 taken. The mouth parts, however, though rudimentary, are 

 mandibulate in type, and there is no approach to the coiled 

 tongue of the Lepidoptera. The antennae are very long and 

 slender, resembling hairs rather than jointed organs. 



The species are found frequently in great numbers along the 

 banks of streams, ponds, or ditches, in which the larval life is 

 passed. The larvae are caterpillar-like, with three pairs of unusu- 

 ally well-developed legs, and live in cases which they make of 

 bits of sticks, moss, leaves, stones, shells, or other material, held 

 together by silken threads with which the entire inside of the 

 habitation is lined. Frequently the cases are roughly and irreg- 

 ularly constructed ; but as often they are marvels of skilled work- 

 manship. Small 



mon name ' ' caddice ' ' or case-flies. Whatever the form of the 

 case, the insect lives in and carries it about everywhere through- 

 out the larval life, crawling about under water by means of the 

 large legs and keeping the soft, white, hind body constantly pro- 

 tected. Some live in ponds or sluggish streams, others in rapid 

 brooks and torrents ; some are vegetarians, some are predatory, 

 feeding on other larvae or even on small fish. Some forms con- 



FiG. 44. 



stones are fitted so 

 carefully that no 

 break as large as 

 a needle-point oc- 

 curs, and some- 

 times they mimic 

 shells so closely 

 that conchologists 

 have been deceived 

 into believing them 

 such. In these 

 cases the lai*vae live, 

 and from them they 

 obtain their com- 



A caddice-fly, Limnophilus vhombicus, its larva, and at a 

 the larval case. 



