The Horn-Tails 



an interesting matter for some observer to work out the life 

 history in detail. 



Life History of a Horn-Tail 



(Phylloecus integer, Norton.) 



This insect, which is known as the willow-shoot horn-tail, 

 is found throughout the eastern part of the United States. The 

 female, after boring a hole some inches below the tip of a willow 

 twig, pushes her ovipositor in an oblique direction into the pith 

 of the twig, inserting the eggs at the bottom of the puncture. 



Fig. 43. — Phylloecus integer. (From Insect Life.) 



She then girdles the twig below the eggs to prevent it from 

 growing any farther, obviously to prevent the egg from being 

 crushed by the rapid growth of the plant. After a week the 

 eggs hatch, the young larvae bore their way down through the 

 pith to a distance sometimes more than two feet, filling the 

 channel behind them with their excrement as they proceed. 

 The eggs having been laid in the spring, the larvse feed all 

 through the summer and become full-grown in late fall, filling 



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