54 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



or more of the cast chrysalid skins projecting from the stumps of the pin 

 oak ; one pupa was alive early in April. It is said by Fitch to be more 

 common in the Southern and Southwestern States than in the Northern. 

 It is also an inhabitant of California, and may be found to occur in 

 nearly all the United States wherever the black, red, and white oak or 

 locust trees grow. The habits and metamorphoses of the moth were 

 first discovered by Peck,* who bred it from caterpillars found in the 

 locust, but Harris afterward discovered that it " perforates the trunks 

 of the red oak." Bailey states that it also feeds on the willow. (Bull. 

 No. 3, Div. Ent., U. S. Dept. Ag., p. 54). 



Eiley states that the male caterpillar is only half as large as the 

 female. He adds that with her extensile ovipositor the moth deposits 

 her eggs in the deep notches and dark bottoms of crevices. "The 

 young worms which hatch from them are dark brown with large heads ; 

 they are active and commence spinning as soon as they are born " 

 (Amer. Ent., ii, 127). He finds it more partial in the West to the 

 locust than to the oak. 



The following account of its habits and transformations is copied from 

 Fitch ; 



Of all the ■wood-boring insects in our land this is by far the most pernicious, wound- 

 ing the trees the most cruelly. The stateliest oaks in our forests are ruined, probably 

 in every instance where one of these borers obtains a lodgment in their trunks. It 

 perforates a hole the size of a half-inch auger, or large enough to admit the little 

 finger, and requiring three or four years for the bark to close together over it. This 

 hole running inward to the heart of the tree, and admitting the water thereto from 

 every shower that passes, causes a decay in the wood to commence, and the tree never 

 regains its previous soundness.! 



This is also a most prolific iusect. The abdomen of the female is so filled and dis- 

 tended with eggs that it becomes unwieldy and inert, falling from side to side as its 

 position is shifted. A specimen which I once obtained extruded upwards of three 

 hundred eggs within a few hours after its capture, its abdomen becoming diminished 

 hereby to nearly half its previous bulk ; and in the analogous European species more 

 than a thousand eggs have been found on dissection. It hence appears that a single 

 one of these insects is capable of ruining a whole forest of oak trees. This calamity, 

 however, is prevented, probably by most of the eggs being destroyed, either by birds 

 or by other insects, for these borers are by no means so common in our trees as the 

 fecundity of their parents would lead us to expect. 



Our moth comes abroad, as already stated, in June and the forepart of July. It flies 

 only in the night time, remaining at rest during the day, clinging to the trunks of 

 trees, its gray color being so similar to that of the bark that it usually escapes notice. 

 In repose its wings are held together in the shape of a roof, covering the hind body. 

 From observing her motions in confinement, I think the female does not insert her 

 eggs into the bark, but merely drops them into the cracks and crevices upon its outer 

 surface. They are coated with a glutinous matter which immediately dries and 

 hardens on exposure to the air, whereby they adhere to the spot where they touch ; 

 and if the short two-jointed ovipositor be not fully exserted as the egg is passed 



* Mass. Agr. Report and Journal, Vol. v, p. 67, with a plate, 1818. 



t We have observed that the old burrows are lined by a dark layer, consisting of a 

 mealy debris about as thick as pasteboard ; this detritus is probably composed of the 

 castings of the larva, which form a paste that in drying strongly adheres to the sides 

 of the gallery. — A. S. P. 



