36 



MISC. PUBLICATION 273, U. S. DEFT. OF AGRICULTURE 



top and lower side. Species wliicli attack the twigs of coniferous 

 trees usually belong to the genera Anthaxia, Chrysophana, Chryso- 

 hothris, or MeJanophiJa. There are many small species of flatheaded 

 borers which mine under the bark and kill the twigs of broacl- 

 leaA'ed trees. Some of the most striking work of this character is 

 done by species of Agrilus, which make spiral girdles in the twigs 



FiGUKE IG. — Spiral twig girdling is characteristic of Agrilus. 



of oak, birch, Avillow, and other broadleayed trees (fig. 16). Some 

 of the western flatheaded twig borers and girdlers include the 

 following : 



Species Hosts and distribution 



Anthaxia aeneogaster Cast Pines, firs, cypress, redwood, oak, willows, 



and other forest and shade trees. West- 

 ern States. 



Clirijsopliana placida Lee Pines, firs, cedars, and hemlock. All West- 

 ern States. 



Chrysohothris iuaJi Horn (lo) Alder, ash, aspen, beech, maple, poplar, 



willow, and many other hardwoods. 

 Throughout the Western States. 



Chrysodotliris femorata F. (15) Alder, ash, aspen, oak, poplar, willow, maple, 



beech, and many other hardwoods. 

 Throughout the United States. 



Agt'ilus angeJicus Horn Oak. California. 



Agrilus poUtus Say Alder, willow, and other broadleaved trees 



and shrubs. 



Agrilus anxius Gory Birch, willow, and aspen. Eastern States 



and Avest into Colorado and Idaho. 



Agrilus 'bilineatus Web i Oak and chestnut. Eastern States and west 



into Colorado. 



The adult long-horned beetles of some species of the family 

 Cerambycidae girdle the limbs and twigs of yarious hardwoods and 

 thus 2^repare them for the feeding of the larvae. These rounclheaded 



