TOPICS FOR STUDY OP INSECTS. 



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respect to food one is a vegetable feeder the other preys upon 

 insects ; the second requires keen sight on account of its 

 feeding habits, its eyes are twice as conspicuous as those of the 

 grass-feeder ; the differences in their legs strikingly reflect the 

 differences in their habits but not more than the wings do. 



Female Dragon-Fly. 



Have the pupils imagine a grasshopper and a dragon-fly 

 exchanging wings and then how the exchange would handicap 

 each in its feeding habits. 



Topics for Study Of Insects. — Appearance, form, motions; 

 food ; means of escape and defence ; structure in general out- 

 line. True insects have six, jointed legs, spiders have eight 

 legs, worms lack jointed legs. 



Metamorphosis : — Complete — egg, larva, pupa, imago — as in 

 butterflies, moths, beetles, flies, bees, ants, etc. ; incomplete — 

 egg, nymph, adult — as in grasshoppers, may-flies, dragon-flies. 

 Molting of larvae and nymphs. Pupa as chrysalis, cocoon. 



Modes of life : — individual, communistic — as illustrated by 

 house-flies, tent-caterpillars, cabbage-worms, plant-lice, hive- 

 bees, ants, etc. 



Modes of feeding : — Many insects, as potato-beetle, tent- 

 caterpillar and tomato-worm, bite their food ; others, as the 



