INSECTS BORING IN THE ROCKY MOUNTAIN SPRUCE. 859 
these circumstances I have little doubt but that it bores into this tree. 
There is a great disparity in size and color between the sexes, and the 
male is much the smaller and is blue- black, with most of the elytra deep 
brick-red, the ends of the elytra being blue-black, as well as an oblong 
oval spot at the base of the united elytra ; the terminal two-thirds of 
the abdomen is reddish; it is 16 mm long; the female is 21 mm long, and 
entirely blue-black. It was identified by Dr. Horn. 
6. Scolytu8 unispinosus Lee. 
Mr. J. B. Smith gives the following account of this borer in Entomo- 
logica Americana, n, 1886, p. 125. 
A few days since (July 12, 1886) Mr. L. E. Ricksecker, of Sylvania, Occidental P. O., 
Cal., sent me a section of Douglass spruce (Abies douglassii) infested by a Scolytid, 
about which he writes as follows : "The wood is a small section from the upper limb 
of a Douglass spruce, which was cut down on April 9, 1886. Many species of Coleop- 
tera attacked the tree on the same evening in a perfect swarm. Next day and there- 
after but few of these were seen. Other species, however, made their appearance, 
and among these were numbers of Scolytus unispinosus Lee. For a week I could see 
them moving hurriedly up and down the limbs of the prostrate tree. Then they be- 
came less, and by May 6 only a few stragglers could be found. 
Noticing that something was boring in these limbs and throwing out little piles of 
dust, I cut out patches of bark, and found in every case two Scolytus occupying a 
straight gallery ; one, presumably the male, being at the opening, and the other at 
the far end. At that date, May 6 to 10, the burrows were about an inch long ; now 
(July 4), the main burrow is two to three inches long, with about twenty-six side 
galleries on each side diverging therefrom. The parent beetles are gone, but at the 
end of each side gallery is a larva, working farther and farther away from the main 
gallery. They work only in the layer of bark nearest the wood, leaving a slight im- 
pression of their galleries on the wood. When full-grown they turn towards the 
surface and there await their transformations." 
To this interesting account of Mr. Ricksecker a few notes based on the specimen 
(now in the National Museum) and on the literature may be not uninteresting. 
The specimen shows two complete main galleries with the larval galleries— -about 
30mm — a length of If inches — at irregular intervals on each side. These extend at first 
at right angles with the main gallery, but become sinuous almost immediately, and the 
larvae change their direction, working upwards above and downwards below the mid- 
dle of the main burrow. Those larvae nearest to the center work longer at right angles, 
but eventually turn either upward or downward, and sometimes change the course of 
the gallery. One gallery shows a larva that first worked at right angles for a distance, 
and then started downward until it came very close to another gallery. Rather than 
enter this it changed its course; went obliquely upward for a distance, and then again 
turned downwards at right angles. Two larval galleries from the same main gal- 
lery rarely cross eacli other, but sometimes two main galleries are close together, and 
then the larval galleries cross and recross in the wiL. est confusion. The main galleries 
are sunken about as deeply into the wood as in the bark ; but the larval galleries 
are deeper in the bark. At the point of entrance there is an enlargement of the 
gallery, of a size sufficient to permit the beetle to turn. 
There are also, in the specimen, five main galleries, with either no larval* galleries 
at all or just started. One of these galleries is interesting, for here the beetle came 
in, formed a small cell, and started downward for half an inch, then changed its 
mind, and turning, started upward for about an inch. In the main galleries no eggs 
seem to be laid within 4 mm of the entrance. Before the parent beetle has finished 
