380 RErOllT OF THE COMMISSIONER OF AGRICULTURE. 



cies of beetle. The insect is figured in all its stages in our Bulletin, 

 and the beetle in Harris's Treatise on Insects, and in other publications. 

 It is a member of the family of long-horned beetles; its antenna? or 

 feelers being about twice as long as the body. Its body is nearly as thick 

 as one's little finger, and it is of a mottled gray color, marbled with 

 white and dark-brown irregular patches. Thus marked it is, while rest- 

 ing on the bark of a moss-grown and lichen-covered fir, spruce, or pine 

 tree protected from the observation of birds, its colors being so assim- 

 ilated to those of the bark of either of those trees that it readily es- 

 capes observation. The beetle appears early in June, and is to be found 

 through the summer until early in September; and at any time in July 

 and August, as well as the first week in September, it lays its eggs in 

 the mauner to be described. 



Professor Riley has described in detail in the New York Weekly 

 Tribune, February 20, 1878, the mode of oviposition of the Bound- 

 headed Apple-tree borer (Saperda bivittata), and his account has since 

 been confirmed in the Rural New-Yorker for January 12, 1884, by Mr. 

 0. G. Atkins. The beetle makes a straight slit in the bark. 



The exact mode of the deposition of their eggs by the Longicorn 

 beetles is imperfectly known so far as we are aware. Perris, in his 

 Insectes du Pin Maritime, describes the mode of oviposition of Ergates 

 faber and Griocephalus rusticus, but not of Monoliammus. We have 

 been fortunate enough to observe the female beetle while at work mak- 

 ing the incision with her jaws, though we have not observed the final 

 act itself of deposition of the eggs. While examining the fir trees on 

 the western shore of Birch Island, Casco Bay, Maine, on a warm, sunny 

 afternoon of August 30, 1 saw a male Monoliammus confusor standing 

 on the bark of a living fir about inches in diameter, within the dis- 

 tance of 2 inches from a female, whose jaws were buried in the bark of 

 the tree on the western side of the trunk, which was exposed to the 

 full rays of the sun. 



On beginning to make the incision, each of the large, sharp, strong 

 jaws of this beetle is pushed directly into the bark; they are then 

 apparently brought together, and the result is a slight curvilinear gash 

 which descends obliquely in the bark. It is probable that the beetle 

 pries up the pad thus formed, so that the freshly-cut edges are exposed, 

 and an opening is thus formed into which the egg is thrust. While 

 watching the female at work the male dropped to the ground, and his 

 consort becoming alarmed withdrew her jaws from the incomplete in- 

 cision, when I seized her. To the end of her abdomen were attached a 

 few fragments of the reddish bark of the fir, and two or three small green 

 pellets, probably excrement; but this showed that she had already de- 

 posited at least one egg, and that the labor was slight, the end of the 

 abdomen probably being simply extended and thrust into the gap of 

 the incision. The Lougicorns, like most other beetles, have no true ovi- 

 positor, but the end of the abdomen is a simple, flattened, horny tube, 

 in which the oviduct terminates; the end of this sheath or tube is prob- 

 ably thrust into the gash made by the jaws. 



By prying up the pad formed by the jaws a shallow but roomy cell or 

 chamber is made for the egg, which lies nearly or quite horizontally, not 

 vertically. 



The egg (PI. V, Fig. 3, a) is very large, ovo-cylindrical, well-rounded, 

 but tapering somewhat at each end, of a dirty-white color, and in length 

 is 4J mm . 



On visiting the tree a week later and removing a portion of the bark 



