72 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 
Fig. 22 
tn*, female 
Graphiguni8 fascia- 
Smith, del. 
Prof. Riley found this insect boring in the wood of a rotten oak- 
st inn p in May, 1872, at St. Louis, Mo. 
The bark called quercitron, of the Quercus 
Hnctoria, is highly valued as a dye, and is much 
worm-eaten by this insect. 
The parent of the worm differs remarkably from all the 
other beetles of this group in that the female is furnished 
with a straight awl-like ovipositor nearly a quarter of an 
inch in length, projecting horizontally backwards from 
the end of her body. The importance of this implement 
becomes manifest when we observe the thickness of the 
bark of the black oak, with its outer layers so dry and 
hard that they form, as it were, a coat of mail, protecting 
the trunk of the tree against the attacks of its enemies. 
Equipped as she is, however, the female of this beetle is 
able to perforate this hard outer bark and sink her eggs 
through it, placing them where her young will find them- 
selves surrounded with their appropriate food. The 
worms from these eggs mine their burrows mostly length- 
wise of the grain or fibers of the bark, and the channels 
which they excavate are so numerous and so filled with 
worm-dust of the same color with the bark that it is diffi- 
cult to trace them. The eggs are deposited the latter part of June, and the worms 
grow to their full size by the close of the season, and will be found during the winter 
and spring, lying in the inner layers of the bark, in a small oval flattened cavity 
about an inch in length, which is usually at the larger end of the track they have 
traveled. 
The larva is divided by transverse constrictions into twelve rings, the last one 
being double. The head is small and retracted more or less into the neck, its base 
white and shining, and its anterior part deep tawny yellow, and along each side black. 
The neck or first ring is much longer as well as thicker than any of the others, the 
two rings next to it being shortest. From the neck the body of the worm is slightly 
tapered backwards to the middle, from whence it has nearly the same diameter to the 
tip, where it is bluntly rounded. Upon the upper side of the neck, occupying the 
basal half of this ring, is a large transverse tawny-jellowspot, rounded upon its for- 
ward side ; but no corresponding spot appears on the under side of this ring. On the 
middle of all the other rings, except the two last, both above and below, is an ele- 
vated, rough, transverse, oval spot of a tawny-yellow color. 
The beetle, like other species of the family to which it pertains, varies greatly in 
its size, specimens before me being of all lengths, from 0.35 to 0.58. It is of an ash- 
gray color from short incumbent hairs or scales, which have a faint tinge of tawny 
yellow except along the suture of the wing-covers. It is also bearded with fine erect 
blackish hairs which arise from coarsish black punctures which are sprinkled over 
the thorax and wing-covers, several of which punctures are in the centre of small 
black dots, which in places are confluent into small irregular spots. The head is of 
the same width as the auterior end of the thorax, and has a deep narrow furrow along 
its middle its whole length, and on the crown is an oval blackish spot on each side of 
this furrow. The face is dark gray, and the antennae are black with an ash-gray band 
occupying the basal half of each of the joints. The thorax is narrower than the 
wing-covers, more broad than long, and thickest across its middle. Upon each side 
slightly back of the middle is an angular projection or short broad spine, blunt at its 
tip. On the middle of the back, between the centre and the base, is a short im- 
pressed line, and on each side of this, extending the whole length of the thorax, is a 
wavy blackish stripe, which is suddenly widened towards its hind end, and is some- 
