APPENDIX 



345 



THE LAKGER APPLE-TREE BORERS. 



By PnoF. F. H. ('hittendkS. 



Among the most troublesome of the insect pests with which the fruit- 

 growers of the United States have to deal are two species of boring beetles 

 known, from the ajipearance of their larvae, as the round-headed and flat- 

 headed apple-tree borers. In addition, there is another species called the 

 spotted apple-tree borer, after the adult form, and to distinguish it from the 

 round-headed borer, which it closely resembles. The two species first men- 

 tioned are common and injurious throughout a wide extent of country — the 

 former to seed fruit trees, the latter also to stone fruit, as well as to a great 

 variety of forest and ornamental, trees: the third is a comparatively rare 

 insect and rather exceptionally injurious so far as known. 



THE ROUND-HEADED APPLE-TREE BORER. 



{Sapercla ranclifln Fab.) 



Fig. 1 — Sapercla Candida : a, larva, from side ; h, IVoiii above ; c, female beetle ; 

 (?,;pupa — all enlarged one-third (original). 



INTRODUCTORY REMARKS AND DESCRIPTION. 



The round-headed apple-tree borer is next after the codling moth, the 

 worst enemy to apple culture in America. 



The first intimation that the grower may have of the presence of this 

 borer in his trees, unless he be forewarned, is in their retarded growth and 

 the sawdust-like castings, consisting of excrementitious matter and gnaw- 

 ings of woody fiber, which the larvae extrude from openings into their bur- 

 rows. This manifestation is usually accompanied by more or less evident 

 discoloration of the bark, and, in early spring, particularly, slight exuda- 

 tion of sap. 



