8 INSECTS INJURIOUS TO FOKESTS. 



and the sides are plastered with clay, forming a hollow tube with sev- 

 eral longitudinal galleries. Their work sometimes extends from 2 to 4 

 feet above the surface of the ground. They leave the outer shell 

 of the wood intact and work up through the longitudinal weathering 

 checks, covering the exterior of the pole with earth to exclude the 

 light. White ants will damage poles that have been set in the ground 

 only two years. Evidently they ente'r the pole from below the surface 

 of the ground. The habits and characteristics of these peculiar and 

 interesting insects have been thoroughly discussed in Circular No. 50 

 of this Bureau by Mr. C. L. Marlatt. 



A giant round-headed borer <^ is sometimes found in the poles, 

 usually in association with the chestnut telephone-pole borer. In 

 poles where the wood is sound this borer apparently works as a rule 

 only in the outer layers of the wood, the galleries running longitudi- 

 nally through the heart below the surface of the ground. In poles 

 where there is decay it will completely honeycomb the heartwood 

 near the surface of the ground. 



In several poles where the wood was "doty" a large Scarabseid * 

 which has before been found in decayed oak railroad ties was present 

 and caused the poles to break off sooner than they otherwise would. 

 The irregular galleries of the grub completely honeycomb the decayed 

 heartwood near or just below the surface. 



A fiat-headed borer "^ and wireworms <* were found in galleries locally 

 in the more or less decayed heartwood of several poles. A large black 

 carpenter ant« does some damage to sound poles set in dry ground 

 through woodland. This ant often widens the longitudinal weather- 

 ing checks and thus accelerates decay. A small black ant-'' was very 

 numerous in many poles, but its work is usually confined to the 

 outer layers of the wood. The work is often throughout "doty" 

 poles. Injury by this ant is not primary, but it also widens weather- 

 ing checks, enlarges other defects, and induces more rapid decay. 



PREVENTION OP THE INJTTBY. 



Doctor Hopkins makes the following statement in a recent bulletin :? 



Insect damage to poles, posts, and similar products can be prevented to a greater 

 or less extent by the preservative treatments which have been tested and recom- 

 mended by the Forest Service for the prevention of decay. These should be applied 



"•Prionus sp. 



*> Identified by Mr. E. A. Schwarz, of this Bureau, as Polymaechus brevipes Lee. 



"Identified by Mr. H. E. Burke, of this Bureau, as Buprestis rufipes Oliv. 



d Species of the family Elateridse. The large larvse of Alaus sp. were especially 

 injurious. 



<" Identified by Mr. Theodore Pergande as Camponotus pennsylvanicus Mayr. 



/ Identified by Mr. Theodore Pergande as Cremastogaater lineolata Say. 



ff Insect Depredations in North American Forests. <^Bul. 58, Part V, Bur. Ent., 

 U. S. Dept. Agr., p. 84, 1909. 



