3 °° 
Beetles 
have special habits which make them comparable in some ways with the 
social wasps, bees, and ants, and with the termites. They live in mines— 
the “black holes” often seen in timber—bored into the heart-wood of sick 
or dead trees, in colonies including numerous adults and many larvae. Their 
food is not the wood of the tree, but consists of certain minute and succulent 
bodies produced by a fungus which grows on the walls of their burrows. 
This fungus does not grow there by chance, but is “planted” by the beetles. 
It is started by the female upon a carefully packed bed or layer of chips, 
sometimes near the entrance of a burrow, in the bark, but generally at the 
end of a branch gallery in the wood. It spreads, or is spread, from this 
forcing-bed to the walls of the various galleries and chambers of the mine. 
The young larvae nip off the tender tips of the fungus stalks “as calves crop the 
heads of clover,” but the older larvae and adult beetles eat the whole structure 
down to its base, from which new hyphae soon spring up afresh. The fungus 
is suitable for the insects only when fresh and juicy: if allowed to ripen, the 
tender protoplasm is shut up in spores, and the galleries are soon filled to 
suffocation with these spores and the ramifying mycelial threads. Indeed 
the colony of ambrosia-beetles—ambrosia being the name applied to the 
tender fungus food—is often overwhelmed and destroyed by the quick 
growth of their garden-patch. If anything happens to interrupt the constant 
feeding on and cutting back of the fungus, the colony is almost always 
destroyed 
