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SOME OF NATURE'S INSECTICIDES. 



1. Wind. Removes from trees. 



2. Temperature. Insects can endure extremes but not variation. 



3. Rain. Destroys plant lice. 



4. Fires. Destroy insects in all stages, especially those infesting 

 decayed wood. 



5. Birds. Prey on the egg, larval, pupa, and adult stages of in- 

 sects. 



6. Predaceous Insects. Prey on other species, in air, as dragon-fly; 

 in water as scavenger beetle. 



7. Inchneumon Flies. Deposit eggs in larva of insects; in mines 

 of the engraver beetle. Remove bark and compare engravings of dif- 

 ferent species. 



8. Mantis. Habits of mantis or praying insect. 



9. Spiders. Traps for catching insects funnel web, orb web. 



10. Frogs and Toads. Structure of mouth for catching insects. 



11. Lady-bug. Destroys San Jose Scale and aphis, very beneficial 

 and should be protected. 



