24 INSECTS INJURIOUS TO FORESTS. 
Termites (Leucotermes spp.) also inhabit subterranean passages. 
Drummond has compared tropical species of termites to earthworms 
and declared that they are equally as beneficial to man in aerating 
the soil. After swarming, many of the sexed adults excavate shallow 
cells in the earth under small pieces of decaying wood, and later enter 
the wood. The royal cell is constructed in decaying wood or in the 
earth slightly below the surface of 
the ground. Termites usually in- 
fest wood by entering from the 
ground underneath, rather than 
directly on the exposed surface, the 
latter being usually the habit at the 
time of the swarm. (Termopsis 
angusticollis Walk. usually infests 
wood by gaining ingress through 
wounds and abrasions.) None of 
the sound traplogs with loose bark 
in the termitarium or in the forest 
was infested except at the point of 
contact with the ground, but ter- 
mites in pairs have been found un- 
der loose split bark on decaying 
logs where more moisture was pres- 
ent. Workers and soldiers are fre- 
quently to be found in the spring 
in small pieces of decaying wood 
lying on the ground, and termites 
probably extend old colonies or es- 
tablish new colonies by means of 
subterranean tunnels. During the 
winter the members of the colony 
are to be found in a labyrinth of 
undergound passages. 
These excavations are of varying 
Fic. 6.—Work of termites in insect-killed southern size and shape, and extend m all di- 
yellow pine. Tree killed in the spring; wood at rections. Some of the tunnels are 
ne tmeveeny enns DMP or4itioned of into separate chan 
bers, while others are unpartitioned 
runways. In the main runways the very young are absent. The 
partitions consist either of uneaten portions of the wood or small coni- 
cal piles of moist earth mixed with frass (excreted, finely digested 
wood) of clay-like consistency. Sometimes in broad, shallow chan- 
nels a small irregular mass nearly blocks the channel. The sides of 
the channels are smooth, and the uneaten masses of wood which 
serve as barricades appear as little islands and are distinct because of 
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