74 INSECTS INJURIOUS TO FOREST AND SHADE TREES. 
Mr. Bryant.* Here she frequently dies, and her remains may be found 
long after her progeny have commenced working. The larve bore their 
cylindrical channels, at first, transversely and diverging (Fig. 34, 1), but 
afterwards lengthwise along the bark (Fig. 34, 2), always crowding the 
widening burrows with their powdery excrement, which is of the same 
color as the bark. The full-grown larva (Fig. 34, 4, natural size and en- 
larged) is soft, yellowish and without traces of legs. The head is slightly 
darker, with brown jaws, and the stigmata so pale that they are with 
difficulty discerned. It remains torpid in the winter, and transforms to 
the pupa state about the end of the following May. The pupa (Fig. 34, 
5) is smooth and unarmed, and shows no sexual differences. The per- 
fect beetle issues through a hole made direct from the sap-wood, and a 
badly infested tree looks as though it had been peppered with No. 8 shot. 
The sexes differ widely from each other, the male having spines on the 
truncated portion of the abdomen, not possessed by the female. The 
eggs are deposited during the months of August and September, and 
the transformations are effected within one year, as no larve will be 
found remaining in the tree the latter part of July. 
Two ichneumon parasites, according to Riley, prey upon this insect, 
and after killing the grub spin little pale cocoons. They are Spathius 
trifasciatus Riley, and Bracon scolytivorus Cresson. 
The beetle—Male entirely black, or black with brown wing-covers; the head above 
flat, concave towards tip; thorax very little longer than wide, and narrowing in 
front but slightly. Elytra with about 10 striz confused at the sides, but regular 
above, and composed of small, deep, approximate punctures; interstitial spaces with 
a single row of minute and nearly obsolete punctures. The female differs in having 
the head rather shorter, more rounded, less hairy, and the venter unarmed. Length 
0.15-0.20 inch. (Riley.) 
13. Sinoxylon basilare (Say). 
Order COLEOPTERA; family PTINID®. 
Inhabits hickory wood, in which it bores to a considerable depth, preferring the 
hard central wood. Its borings are very fine, and firmly compressed. After full 
development is attained it makes its way out almost at a right angle and emerges 
through a circular opening in the bark of the hickory. (Horn.) 
14. RED-SHOULDERED APATE. 
Apate basilaris (Say). 
Order COLEOPTERA; family SCOLYTIDA. 
Boring deep, small, straight holes to the heart of the tree, which is entirely killed by 
this insect, and transforming at the bottom of the hole. 
The beetle is deep black and punctured all over; thorax very convex and rough in 
front; the wing-covers not excavated at the tip, but sloping downward very sud- 
*The mode of operation appears to be as follows: Boring through the bark, the insect forms a ver- 
tical chamber next to the wood, from half aninch to an inch in length, on each side of which it depos- 
its its eggs, varying in number from twenty to forty or fifty in all. The larye, when hatched, feed 
on the inner bark, each one following a separate track, which is marked distinctly on the wood. Some 
trees contain them in such numbers that the bark is almost entirely separated from the wood. In 
many cases the upper part of the tree is killed a year or two before the lower partis attacked. (Riley’s 
Fifth Annual Report Inj. Ins. Missouri, p. 104. 
