.26 



bodies of a dozen or more larvae and immature imagoes, together with 

 the fragments of a predatory beetle, Colydium Uneola Say. This tomb 

 bears testimony to a sanguinary conflict, in which victory crowned the 

 efforts of the ambrosia eaters. The bodies of the slain, both friend and 

 foe, have been consigned to the same sepulcher. In the same figure, at 

 b, is shown a short branch gallery containing the lifeless body of the 

 mother of the colony, who appears to have constructed her own tomb 

 and to have crawled into it as she neared her end. The mouth of this 

 tomb also has been sealed up by the survivors. 



Xyleborus xylogra/phus breeds only in dying trees, and generally in 

 trunks of large size. It appears to be partial to rather hard woods, 

 like oak, hickory, beech, and maple, and is found wherever these trees 

 grow, both in this country and in Europe. It does much injury to tim- 

 ber, and in cut lumber the broad, flat chambers produce defects which 

 can not be remedied by plugging. 



THE GENUS MONAKTHEUM. 



In this genus the sexes are alike, and the males assist the females in 

 forming new colonies. The young are raised in separate pits or cradles, 

 which they never leave until they reach the adult stage. The galleries, 

 constructed by the mature female beetles, extend rather deeply into the 

 wood, with their branches mostly in a horizontal plane (figs. 24 and 25). 



Fig. 24.— Gallery of Monarthrum fasdatum in maple (original). 



The mother beetle deposits her eggs singly in circular pits which she 

 excavates in the gallery, in two opposite series, parallel with the grain 

 of the wood. The eggs are loosely packed in the pits with chips and 

 material taken from the fungus bed which she has previously prepared 

 in the vicinity and upon which the ambrosia has begun to grow. 



The young larvae, as soon as they hatch out, eat the fungus from 

 these chips and eject the refuse from their cradles. At first they lie 

 curled up in the pit made by the mother, but as they grow larger, with 



