A REVISION OF NORTH AMERICAN CHRYSOBOTHRINI 135 



Of nigritula, Philadelphia. Of alabamae, Alabama. Of cribraria, 

 Pennsylvania. Of obscwra, "Southern and Western States," type No. 

 2691, simply labeled with an orange disk. Of misella, "Saratoga," 

 type No. 2690, simply labeled with a pink disk. The types of obscura 

 and misella are in the Museum of Comparative Zoology, Cambridge, 

 Mass., but the present location of the types of the other species listed 

 above is unknown to the writer. 



Distribution. — This is the most widely distributed species of Chryso- 

 bothris in North America, as it has been recorded from Mexico, all parts 

 of Canada from the Atlantic to the Pacific Ocean, and from all sections 

 of the United States. It has been found in imports into New Zealand 

 and the Hawaiian Islands. Material has been examined from the Dis- 

 trict of Columbia, Lower California, and various localities in nearly 

 all the States. 



Hosts. — This species is recorded as breeding in the bark and sap- 

 wood of a great variety of dead or dying fruit and forest trees. Trees 

 that had been recently planted and have not become well established 

 seem to be especially susceptible and are the easy prey of this insect. 

 Adults have been recorded as feeding at the base of the twigs and as 

 partially defoliating young trees. Trees may be killed outright, or 

 the tops killed the first season and the lower part of the tree attacked 

 during a later season. Material has been examined by the writer that 

 was reared from the following trees: Aspen {Populus tremuloides 

 Michaux), sycamore {Platanus occidentalis Linnaeus), silver maple 

 {Acer saccharinum Linnaeus) , black walnut {Juglans nigra Linnaeus) , 

 chestnut (Oastanea dentata (Marshall) Borkhausen), white willow 

 {Salix lasiolepis Bentham) , Highland live oak (Quercus wislizenii De 

 Candolle), coast live oak {Quercus agri folia Nee), valley white oak 

 {Quercus lobata Nee), California black oak {Quercus kelloggii New-. 

 berry), white oak {Quercus alb a Linnaeus), willow oak {Quercus lauri- 

 folia Michaux), red gum {Liquidambar styraciflua Linnaeus), Ameri- 

 can elm {Ulm/us americana Linnaeus), hackberry {Celtis occidentalis 

 Linnaeus), Japanese redbud {Cercis japonica), apple {Malus sp.), 

 boxelder {Acer negundo Linnaeus), red ash, {Fraxinus pennsylvanica 

 Marshall), red maple {Acer rubrum Linnaeus), mountainash {Sorbus 

 sp.), pin oak {Quercus sp.), red oak {Quercus sp.), peach {Amygdalus 

 persica Linnaeus),, plum {Prwrvus domestica Linnaeus), and Chinese 

 elm {Ulmus parvi folia) . 



The size, color, sculpture, and color and shape of the foveae on the 

 elytra are quite variable. The color of the head varies from bronzy 

 green to bronzy cupreous, and frequently there are two small, smooth 

 callosities or chevrons on the front. Sometimes the antenna is uni- 

 formly bronzy green, in which case the outer margins of the segments 

 are piceous. The foveae on the elytra vary in color from bright green 

 to reddish cupreous, and are sometimes divided by the costae. The 

 sides of the pronotum are usually parallel and sinuate at the middle, 

 but occasionally specimens are found with the sides obliquely converg- 

 ing from near the apex to the base. The sides of the male genitalia 

 are more strongly constricted in some specimens than in others, and the 

 teeth on the tibia are variable in size and number, frequently varying 

 in number on the anterior tibiae of the same specimen. The eighth 

 abdominal tergite of the female is variable in shape, sometimes very 



