, l8 SEVENTH REPORT OF THE FOREST, FISH AND GAME COMMISSION. 



portion of the excrement is evidently utilized to form tlie fungus or food bed. The 

 mother beetle is constantly in attendance upon the young during their develop- 

 mental period and guards them with jealous care. The mouth of each cradle is 

 closed with a plug of the food fungus, which,- as fast as it is consumed, is renewed 

 with fresh material. The grubs perforate this plug from time to time and clean out 



OQo 



FIG. i8. GALLERIES OF MONARTHRCM MALI IN MAPLE. 



AFTER HUBBARD, U. S. DEPT. AGR., DIV. ENT. BUL. 7, N. S. '97. 



their retreats by pushing the pellets through the opening, where they are removed 



by the mother, who seals it again with ambrosia. The transformations to the adult 



occur in these lateral pits or cradles. 



Description. The parent beetle is a minute, 

 reddish-brown, cylindrical insect, about - ^', of 

 an inch long. The shape of the antennal 

 club, the puncturing of the prothora.x and the 

 linear dotting of the elytra are well shown in 

 figure 17. The elytral declivity is slightly 

 excavated and marked by two rather incon- 

 spicuous teeth on each side. 



This insect enters the dying or dead tree 

 vertically for a distance of about i^/'^ inches 

 and from that point inward b-'anches may 

 diverge at oblique angles. The brood cham- 

 bers arc nearly ^s of an inch long and extend 

 vertically above and below the main branches, 

 figure 18. 



Natural Enemies. Only one natural enemy, 

 so far as known to the writer, has been 



recorded. Dr. A. D. Hopkins states that he found the predaceous beetle, Colydiuin 



lincola Sa\-, with this species in jack oak. 



FIG. It). AMBROSIA OF MONARTHRUM 

 .MALI, GREATLY ENLARGED. 



AFTER HUBBARD, U. S. DEt'T. AGR., DIV. ENT. BUL. 7, 

 N. S. "97. 



