3920) MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
haps all species of spruce. It is more widely distributed in pine for- 
ests than any other American scolytid, being found from the Atlantic 
to the Pacific and from Alaska to Guatemala. Attacks by this beetle 
are made principally on stumps and at the bases of standing trees. 
The egg galleries are longitudinal, extending downward from the point 
of entrance, which is usually marked by a large pitch tube. The gal- 
lery is often extended down to, or even below the surface of the mineral 
soil, and may range from less than a foot to several feet in length. The 
eggs are laid in irregular masses in grooves in the sides of the egg 
gallery, from which they are separated by a wall of frass, thus allow- 
ing free passage of the beetles without injury to the eggs. 
Upon hatching, the larvae feed together and destroy considerable 
areas of the inner bark. When approaching full growth, however, 
many of them bore short individual mines in which they pupate and 
transform to adults, while cthers surround themselves with a wall of 
frass in the common feeding chamber and there complete their trans- 
formation. In most parts of the country the beetle completes only 
one generation a year, but in warmer areas two generations may be 
completed in a single season. 
The favorite breeding place for this insect is in the bark of recently 
cut stumps or in the bases of standing trees dying from other causes. 
The odor of newly sawed lumber and fresh pitch exerts a powerful 
attraction, however, and in the presence of such an odor the beetles 
often attack healthy, living trees. Such attacks are usually unsuccess- 
ful in vigorous bark, and while the beetles may persist in their efforts 
for several weeks and may form a large pitch tube, eventually they 
elther abandon their burrows or succumb to the flow of resin. Many 
trees affected by disease or by the attack of other insects, or weakened 
by fire, flooding, or drought, die after being attacked by the red tur- 
pentine beetle. 
In areas where lumbering is continued for a number of years this 
insect often breeds up to countless thousands. If such operations are 
suddenly discontinued these beetles, lacking the usual breeding mate- 
rial, will attack healthy trees, causing catfaces, and will kill decadent 
trees in the residual stand. They often leave such an area in swarms 
of thousands of individuals. Such swarms are attracted to new 
buildings that are being erected or to buildings being painted, and 
create a nuisance for a few days. Control of bark beetles is discussed 
on pages 47-51. If lumbering is to be suddenly discontinued the bark 
of stumps and cull logs should be removed. 
The black turpentine beetle (Dendroctonus terebrans) is very 
similar to the red turpentine beetle, except that it averages slightly 
smaller and is darker, its color ranging from piceous to black. It is 
much more limited in its distribution, being found only in the East- 
ern States from New Hampshire to Florida and Texas. Its habits 
are very similar to those of D. valens. 
Members of the genus Phloeosinus, known as the cedar bark beetles, 
are characterized by their rather stout form. They range from red- 
dish brown to black in color, and from 2 to 3.5 mm. in length. The 
eyes are deeply emarginate on the inner border, the antennae have five- 
jointed funicles and elongate clubs with oblique sutures, and the rear 
of the elytra have the first, third, and alternate interspaces elevated 
and more strongly tuberculate. 
