182 



ENTOMOLOGY. 



case may be, stung by the parent, whose instincts are exer- 

 cised in selecting the proper plant, and portion of plant, to 

 sting. Although the gall-flies are not the direct architects 

 of the galls, no collection of insect-products would be com- 

 plete without a series of galls, of which there are so many 

 kinds. 



Intermediate between leaf and wood miners, and case- 

 worms, are certain Pyralid moths which not only crumple 

 and roll up the leaves of plants, but piece out their mines 

 by tubular additions to the openings, which form cases in 

 which the caterpillar securely hides. As examples are 

 Acrobasis juglandis and PUycita nebulo. Another Pyralid 

 (Phycis riibnfascielld) mines the buds and recently ex- 

 panded young leaves of the pig-hickory, and also bores 

 into the base of the leaf-stalks. It also builds out the 

 mouth of its mine, adding a tube formed of grains of 

 its excrement, in which it lives and finally 

 transforms. 



Besides mining leaves, which is one of 

 the humblest kinds of architectural effort, 

 certain Tineid moths construct flat, oval, 

 or cylindrical silk-lined sacks or cases in 

 which they live, and which, like Diogenes 

 and his tub, they carry about with them. 

 The clothes-moth in its larval stage con- 

 structs the too-familiar cases of felting, 

 formed of closely-woven bits of woollen and 

 lined with silk. A whole group of sack- 

 bearers (Psychids), small and large, build 



FIG. 231. Case of 

 the basket-worm. 

 After Harris. 



FIG. 332. Larva and case of Chlamys. 



spindle-shaped sacks covered with bits of leaves and twigs, 

 which are so arranged as to resemble basket-work. One of 



