Circular No. 130. issued December lo, 1910. 



United States Department of Agriculture, 



BUREAU OF ENTOMOLOGY. 

 L. O. HOWARD, Entomologist and Chief of Bureau. 



THE OAK PRUNER." 



{Elaphidion villosum Fab.) 



By F. H. Chittenden, 



In Charge of Truck Crop and Stored Product Insect Investigation?. 



INTRODUCTORY. 



Many sorts of trees, particularly oak and hickory, grown for shade 

 are often noticed with their limbs severed as if with a knife or saw. 

 Underneath these trees numbers of twigs and small branches strew 

 the ground. The severed limbs are from a few inches to 2 or 3 feet 

 long, and on one occasion a limb was seen that measured 10 feet in 

 length and another that was IJ inches rri thickness. Young trees are 

 sometimes felled. An examination of one end, sometimes of both 

 ends, of a severed hmb will show a smoothly cut surface near the cen- 

 ter of which will be seen a more or less oval opening plugged with 

 fine shavings and sawdust (fig. 1, e,J). 



DESCRIPTIVE. 



If one of these Kmbs be split open at the proper time a soft-bodied 

 larva, resembling that shown in figure 1 at a, will be found. This is 

 the larva of the oak pruner. It is nearly cylindrical, soft and fleshy, 

 of a whitish or light yellowish color, and is provided with rudimentary 

 legs (fig. 1,^). 



a Formerly the species under consideration was known under two names, Elaphi- 

 dion villosum Fab. and E. parallelum Newm. The writer, however, has seen an abun- 

 dance of specimens of what are labeled by both names, and while it may be true that 

 there are two species it is certain that the species which breed in the North from 

 the amputated twigs are identical, since the writer has reared both what are known 

 as villosum and parallelum from such twigs. That which breeds in the portion remain- 

 ing on the tree has not been investigated, but it is probably not different. 



Horn believed the two species identical and his opinion should not be disputed 

 until the contrary can be proved. 



?5401°— Cir. 130—10 1 



