THE GENUS DENDROCTONUS. 
If, when first discovered, the depredations of the beetles have 
already involved an extensive area, or if they are neglected until a 
large percentage of the timber is killed, their artificial control will 
be as difficult and expensive as that of a neglected forest fire. Further- 
more, if the depredations occur in an inaccessible section of the 
forest or where the conditions as to labor and other facilities are 
unfavorable for necessary action, nothing more can be done toward 
the control of the beetles than under the same conditions in con- 
trolling a fire. But with the rapid extension of modern forest 
management, lumbering operations, and working plans into the 
principal public and private forests, and especially with the adoption 
of fire-control regulations under an organization of fire patrols and 
rangers, there will be no excuse for neglecting the insects. 
THE BEETLE PROBLEM AS IMPORTANT AS THE FIRE PROBLEM. 
In certain sections of the country and in certain National Forests 
where the more destructive species of beetles are present and a 
constant menace to the standing timber, the beetle problem is 
undoubtedly as important as the forest-fire problem, and therefore 
demands the adoption and organization of beetle-control work, which, 
with little or no additional force and equipment, can be conducted by 
fire patrols and forest rangers. 
The evidence of destructive beetle work is not quite as distinct 
as is the evidence of fire, and can not be seen quite so far, but a 
clump of yellow-top or red-top trees can be seen for a long distance, 
and upon closer inspection the pitch tubes and boring dust on and 
around the trunks of living trees are sufficient danger signals to 
demand that the required action be taken to prevent widespread 
depredations. 
There is one great advantage in the requirements for successful 
beetle control over those for fire control, viz, there is usually a period 
of six to ten months in which to utilize or otherwise dispose of the 
affected timber to destroy the broods of beetles in the bark, while 
a fire requires immediate attention. 
DISTINCTIVE CHARACTERS OF THE GKENTJS.a 
The beetles of the genus Dendroctonus (see figs. 1, 2, 3, etc.) are 
distinguished in the adult stage by their cylindrical, somewhat 
elongate to stout bodies, broad and prominent heads, nearly round 
to oblong-oval and transversely placed eyes behind the base of 
each antenna, the last with an elongate, clublike basal joint (scape) 
followed by 5 short joints (funicle) and terminated by a broad club 
which is thickened at the base and flattened toward the apex, and 
a See also Technical Series No. 17, Part I, for technical descriptions of genus, species, 
etc. 
