94 BULLETIN 108, UNITED STATES NATIONAL MUSEUM. 



longitudinal chambers. Their pellets of excrement are regularly 

 impressed and these sometimes completely fill or block up the bur- 

 rows with a compact mass (pis, 9 to 12). They are often expelled 

 as dry droppings from the infested wood. These termites are destruc- 

 tive to the woodwork and furniture in buildings. The species of 

 these tlu'ee genera never burrow in the ground. 



In Arizona various species of Kaloterrnes burrow in the dry wood 

 of dead cottonwood, poplar, walnut, and "palo verde" trees, also living 

 in hardened wounds of the giant cactus (Cereus giganteus). There is 

 a record of injury to the root of a pear tree by a species of Kaloterrnes 

 at ^Mineral Park, Mohave County, Arizona, on May 17, 1890. 



Prorliinotermes simplex is similar in habits to species of Retic- 

 ulitermes, except that it is not subterranean. This termite is a 

 destructive wood borer and injurious to timber. 



Food. 



The principal food of termites is cellulose, wliich they obtain from 

 dead or living vegetation. Dr. M. Oshima, expert zoologist, Goverr- 

 ment of Formosa, has kept termites alive by feeding them on filter 

 paper or cotton. Osliima has proven that when they eat the spring 

 wood, the hard lignin-cellulose is not digested, as can be verified by 

 testing with hydrocliloric acid, when the lignin reaction is obtained. 



The young are fed on prepared food wliich is fed from the mouths 

 of the adult insects. 



Workers, soldiers, and nymphs often solicit hquid from the anus 

 of other termites, especially from the reproductive forms. Tliis sub- 

 ject will be discussed later under the heading "Trophallaxis." 



Damage. 

 character and extent of damage done by termites. 



Hagen (1876) states that termites retreat step by step before 

 advancing cultivation. However, this is only partially true. Wlien 

 their breeding places in dead trees, logs, and stumps are destroyed 

 they then infest fences, telephone poles, and the foundations and 

 woodwork of poorly constructed buildings. 



It has already been noted that species in the various genera show 

 very characteristic differences in the manner in which they bore 

 through wood, and their work or "Frassbilder" (Assmuth, 1913) is 

 quite distinct. The impressed pellets of excrement expelled by some 

 species enable generic determination. Dudley in his paper on "The 

 Termites of the Isthmus of Panama" (1890) writes that the various 

 species can be distinguished by their work, galleries, and nests, and 

 that the remedy in each case must be different. These facts are all 

 very useful in combating these insects. 



In the United States damage by termites to the woodwork of 

 buildings and to their contents, while not so great as in the Tropics 



