CHILDREN'S GARDENS 



sary to have a knowledge of their life histories 

 or metamorphoses. Some develop without meta- 

 morphosis. The stages are, egg, immature in- 

 sect and adult; as, a silvery fishmoth. Many 

 have incomplete metamorphosis. The stages 

 are egg, nymph (several stages) and adult; as, 

 locust, cricket, dragon-fly, damsel-fly, May-fly. 

 Some of the most injurious insects have complete 

 metamorphosis. The stages are, eggy larva, 

 pupa, imago, or adult; as, moths, butterflies, 

 bees, ants, beetles and flies. 



There are nineteen orders of insects, only 

 six of which are of great economic significance. 

 These are Orthoptera, Hemiptera, Lepidoptera, 

 Diptera, Coleoptera and Hymenoptera; they 

 include some of the most numerous and destruc- 

 tive though interesting species. 



Hordes of insects are destroyed by Nature's 

 insecticides: the wind removes them from the 

 trees ; changes of temperature destroy many, be- 

 cause they can endure extremes but not varia- 

 tions in temperature; rain destroys plant-lice; 

 fire makes havoc with insects in all stages, espe- 

 cially those infesting decayed wood ; predaceous 

 insects devour other insects ; the air is cleared of 

 gnats and flies by dragon-flies, and water-insects 

 are destroyed by the scavenger-beetles; the ich- 

 neumon-flies deposit their eggs in the larvae of 

 other insects and in the mines of the engraver- 



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