Bui. 437, U. S. Dept. of Agriculture. 



Plate IX. 



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111 



Work of Flat-Headed Borers. 



Fig. 1.— Eggs of Agrilus angelicus laid singly on twigs of live oak (Quercus agrifolia). 

 XL Fig. 2.— Egg of Agrilus sp. laid singly on stem of manzanita (Arctokaphylos 

 viscida). Xf. Fig. 3.— Egg masses of Agrilus politus on bark of stem of arroyo 

 willow (Sali.c lasiolcpis). Some covered with the protective covering, some uncov- 

 ered. XI . Fig. 4.— Egg masses of Agrilus sp. on bark of trunk of white alder 

 (Alnus rhombifolia). Xf. Fig. 5.— Trunk of living white alder (Alnus rhombi- 

 folia) showing egg masses of Agrilus sp. and the sap flowing from the wounds 

 caused by the feeding of the young larvae. X^V Fig. 6.— Sections from the trunk 

 of a living white alder (Alnus rhombifolia) showing old egg masses on the bark 

 larval work under the bark, and the "craters" formed in the bark when the 

 attack was not severe enough to kill the tree. The brood died in the larval stage 

 and the wound will cause a check in the wood. XI. (Photographs by H. E 

 Burke.) (Original.) 



