INSECT ENEMIES OF WESTERN FORESTS 131 



The western cedar bark beetle [Phloeosinus punctatus Lee.) at- 

 tacks the trunk and larger limbs of western red cedar, incense cedar, 

 Alaska cedar, and Port Orford cedar in the mountains of the Pacific 

 Coast States and eastward through the range of western red cedar. 

 It is a common species and at times quite injurious to living trees. 

 The galleries consist of either one short tunnel, not over an inch 

 in length, or two short tunnels in the form of a V. The beetles 

 are dark red to black and about one-eighth inch long. 



The juniper bark beetle (Phloeosinws juniperi Sw.) is dark brown 

 and about one-eighth inch in length. It attacks the trunks of west- 

 ern juniper in California and Oregon. P. scopulorum Sw. breeds in 

 Juniperus scopulorwn in British Columbia and southward into 

 Washington. P. utahensis Sw. breeds in J. monosperma in Colorado 

 and Utah. 



The redwood bark beetle {Phloeosinus sequoiae Hopk.) (^^) is 

 one-eighth inch long and the largest of the genus. It attacks weak- 

 ened, felled, or fire-scorched redwood (fig. 64), western red cedar, 

 and Port Orford cedar along the coast from British Columbia to 

 central California. 



The bigtree bark beetle {Phloeosinus rubicundulus Sw.) works in 

 broken branches of big trees {Sequoia w ashing toniana) in their 

 native groves in California. 



The cypress bark beetles, Phloeosinus cupressi Hopk. and P. cris- 

 tatus Lee, are at times very destructive to the various species of 

 cypress in California. Besides killing many trees outright, they 

 mine and kill the twigs of ornamentals, making the trees very un- 

 sightly. The Sargent cypress bark beetle {Phloeosinus variolatus 

 Bruck) is a large species which works in Sargent cypress in Califor- 

 nia. Other small species of cedar bark beetles which work mainly 

 in twigs are discussed on page 32. 



Baek Beetles Affecting Broadleaved Teebs 



Certain species and genera of bark beetles confine their attacks to 

 various broadleaved forest trees. Some of these are important 

 enemies of shade trees, park trees, and ornamentals. Some of the 

 more common are mentioned in the following paragraphs: 



The alder bark beetle {Alniphagus aspencollis Lee.) is a common, 

 and often quite destructive enemy of western alders from British 

 Columbia southward through California. The beetles usually at- 

 tack weakened, dying, or felled trees. The adults are small, 

 robust bark beetles about one-eighth inch long. They bore through 

 the bark in pairs, usually at the base of branches, and construct a 

 longitudinal Qgg gallery from 2 to 5 inches long, with no apparent 

 nuptial cell. Eggs are placed close together along both walls of 

 the gallery, with as many as 50 eggs to the inch. The larvae work 

 out from the Qgg gallery and pupate in the soft inner bark. There 

 appear to be two generations a year, with attacks occurring through- 

 out the growing season. 



The ash bark beetle {Leperisinus calif ornicus Sw.) breeds in felled 

 or dying ash trees in California and Oregon, and under certain con- 

 ditions may be injurious to living trees. The adults are small bark 

 beetles covered with scales. They construct Qgg galleries beneath 

 the bark, with two transverse branches starting from a central en- 



