690 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



piue tree, protected from the observation of birds, its colors beiug so 

 assimilated to those of the bark of either of those trees that it readily 

 escapes 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 manner to be described. 



The exact mode of the deposition of their eggs by theLongicorn bee- 

 tles is imperfectly kuown so far as we are aware. 



Professor Riley has described in detail in the New York Weekly 

 Tribune, February 20, 1878, the mode of oviposition of the Round-headed 

 Apple-tree borer {Saperda Mvittafa), and his account has since been 

 confirmed in the Rural New Yorker for January 12, 1884, by Mr. C. G. 

 Atkins. The beetle makes a straight slit in the bark. Perris,in h\sl7isects 

 du Pin Maritime, describes the mode of oviposition of Ergates faher and 

 Cnocephalus rusticus, but not of Monohammus. We have been fortu- 

 nate enough to observe the female beetle while at work making the in- 

 cision 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, I saw a male Monohammus confusor standi ug on the bark of 

 a living fir about 9 inches in diameter, within the distance 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 ap- 

 parently 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 freslily cut edges are exposed, 

 and an opening is thus formed into which the &gg 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 ab- 

 domen were attached a few fragments of the red- 

 dish bark of the fir, and two or three small green 

 pellets, probably excrement; but this showed that 

 she had already deposited at least one egg, and 

 that the labor was slight, the end of the abdomen 

 Fig. 228.— a, egg; and h, probably being simply extended and thrust into 



freshly hatched larva of ,, z- j.i • • • mi t • i-i 



MonoLn^nus confusor. ^^^ g^p of the lUClSlOU. The LoilglCOmS, like 



most other beetles, have no true ovipositor, 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 probably 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. 



