224 



BARK-BEETLES; ENGRAVER-BEETLES. 



mother beetle is constantly in attendance upon her young during 

 the period of their development, and guards them with jealous 

 care. 



"The mouth of each cradle is closed with a plug of the food 

 fungus, and as fast as this is consumed it is renewed with fresh 

 material. The larva; from time to time perforate this plug and 

 clean out their cells, pushing out the pellets of excrement through 

 the opening. This debris is promptly removed by the mother, 

 and the opening again sealed by ambrosia. The young transform 

 to perfect beetles before leaving their cradles and emerging into 

 the galleries. 



Fig. 237. — Ambrosia of Corthvlus punctatissimus, Zimro.; a, detached bumb-bell 

 shaped pairs of cells, greatly enlarged. After Division of Entomology, V. S. Depart- 

 ment of Agriculture. 



"The Ambrosia of Monarthrum (Fig. 237), is moniliform, 

 and resembles a mass of pearly beads. In its incipient stages a 

 formative stem is seen which has short joints that become globular 

 conidia and break apart. Short chains of cells, sometimes show- 

 ing branches, may often be separated from the mass. The base of 

 the fungus mass is stained with a tinge of green, but the stain 

 in the wood is almost black.* 



"Two species, M. fasciatum Say, (Fig. 238), and M. mali 

 Fitch (Fig. 239), are confined to the Atlantic forests, and range 

 in latitude from Lake Superior to Florida. They have identical 



*By mistake the ambrosia of another closely related beetle has been illustrated. 



