HYLASTES CUNICULARIUS, ER. 27 



From the table on p. 26 it will be seen that H. ater and 

 H. cunicularius are very similar. The sparse puncturing on 

 the disc of the thorax in H. ater, however, causes the thorax 

 to appear shiny, and this feature, together with the more 

 elongate appearance of the beetle, is a most useful character 

 for distinguishing H. ater from H. cunicularius in the field. 



The Egg. — The egg of H. cunicularius does not call for any 

 special notice. It is oval in shape, shining white in colour, and 

 shows neither sculpturing nor micropyle. It does not differ from 

 the usual scolytid type of ^gg. 



The Larva. — The larva of H. cunicularius is of the typical 

 scolytid type, a curved, whitish, legless grub with yellow head 

 and biting jaws. 



The Pupa. — Except in the distinctly oval shape of the pro- 

 thorax, the pupa of H. cunicularius does not differ markedly 

 from that of the other members of the genus. 



The Brood Gallery.— The "Brood" or "Mother" gallery 

 oi H. cunicularius is typical of the species. It conforms to the 

 Hylastes type in being crutch-shaped. Its distinctive features 

 are its breadth, its shortness, and the short equal arms of the 

 crutch. Its shortness contrasts it with that of H. ater, which is 

 long and narrow, and the equal arms of the crutch contrast it 

 with that of H. palliatus, in which (and this is also a feature of 

 If. ater's gallery) one arm of the crutch is invariably consider- 

 ably longer than the other. 



The "crutch" is the so-called brood chamber. It is the 

 first portion of the gallery to be cut. In it the male is 

 usually found while the female is cutting the mother gallery 

 proper. 



Figure i is a sketch of a typical cunicularius brood gallery 

 cut in a spruce root, half an inch in diameter. It shows the 

 typical small crutch, which in the gallery figured is slightly 

 deflected (a very common feature), and the e^gg niches, which 

 are invariably cut in the bast and bark. The black circle at the 

 foot of the gallery is the entrance, while a shows the gallery as 

 cut in the bark, and b its counterpart on the root itself. In b it 

 will be seen that the ^<gg niches are absent and that the shape 

 of the gallery is much less definite. 



The Larval Galleries. — The larval galleries arise at right 

 angles to the mother gallery, from the ^gg niches. At first they 

 are distinct, but this is only for a very short distance, as they 



