32 



ENTOMOLOGICAL SOCIETY OF ONTARIO. 



From this emerges in course of time the splendid butterfly, Fig. 26, which soarB so. 

 gracefully through the summer air. 



Fig. 26. 



The larva (larva, a mask) is frequently without external organs and has a biting- 

 mouth : hence, it is a great feeder and usually very destructive to vegetation. The larval 

 condition continues from two to six weeks in most ; but there are some in which it is 

 more than a jear, e.g.. the wire worm, white grub, and some "borers." 



Pupa (pupa, a doll). This is generally a resting condition, which, in summer, 

 usually lasts but a short time (about two weeks) ; but if entered in autumn, continues 

 till the next spring. The term chrysalis (c/irysos, gold) is often applied to this stage in 

 butterflies, because in some it is dotted with golden spots. In most moths a cocoon is 

 woven around the pupa. Nymph is applied to the young of such as do not undergo com- 

 plete metamorphosis in development ; in such the young are much the same in appearance 

 as the adult, but smaller, and usually wingless; eg., grasshoppers, bugs, etc. 



Imago (imago, an image). This term is applied to the perfect insect, which is often 

 harmless, as far as feeding upon vegetation is concerned. 



The following names show some of the common terms applied to these stages in some 

 orders of insects : 



Larva Pupa Imago. 



Borer, grub " Beetle. 



Maggot " Fly. 



Caterpillar or worm Cocoon Moth. 



" " Chrysalis Butterfly. 



Nymph Nymph Grasshopper. 



Fig. 27. Fig. 28. 



II. — Insects may be Beneficial or Injurious. 



Beneficial. — The bee (honey) • silkworm (silk) ; cochineal (dye) ; ichneumon (feeds 

 on injurious insects). 



Injurious. — Those affecting the products of the field (midges, Fig. 27, the wheat 

 midge, etc.) ; the garden (cut-worms, Fig. 28, etc.) ; the orchard (borers, Fig. 29, etc.) 



