FUNCTIONING OF THE SOIL SYSTEM - Soil Ecology - page 499

i. Grass-harvesting species. These species largely harvest the dead leaves of grasses
which may be stored in their nests; they belong to the families Hodotermitidae and
Termitidae. Unusually, the northern Australian rhinotermitid species Schedorhinotermes
derosus harvests standing grasses, mostly dead but some living, in addition to the diet of
wood characteristic of this family (Watson, 1969). The Neotropical termitid harvester
Syntermes praecellens also harvests green leaves (Roonwal, 1970). A number of species
in this category also collect litter: the tropical Australian species Drepanotermes
rubriceps stores a wide range of materials in its low epigeal mounds including the leaves
of grasses, broad leaved species and a diversity of seeds and small woody litter (Gay
and Calaby, 1970).
ii. Litter-feeding species. Species in this category feed on a broad variety of litters on
the soil surface in diverse habitats ranging from savannas to tropical rainforests.
Food materials in this class include the partly-decomposed and finely subdivided litter
of grasses and broad-leaved species, leaves, seeds, twigs and animal faeces. While a few
species of this group belong to the lower termites, most species of this category belong
to the Termitidae, including the fungus cultivators of the subfamily Macrotermitinae.
Amitermes laurensis is a widespread and common species in northeastern Australia
where it builds low approximately-conical mounds in well-drained areas but elongate,
wedge-shaped mounds where drainage is impeded (Gay and Calaby, 1970). Populations
of mounds may exceed in favourable locations. Its food comprises small seeds,
pieces of dead grass, the dung of domestic animals and other finely-divided vegetable
matter (Lee and Wood, 1971a).
In the humid West African rainforest, the fungus-cultivating termite Macrotermes
mülleri collects leaf litter which it shreds into small pieces. On returning the subdivided
leaf materials to its nest, they are moistened with saliva and stored for a period prior to
adding them to the fungus comb, possibly in an initial fermentation stage (Garnier-
Sillam et al., 1988a).
iii. Wood-feeding species. These may be separated into three smaller groups comprising
species feeding on a decay series:
wood in living trees;
sound, largely-undecomposed wood;
partly-decomposed wood.
The wood-feeding habit occurs in species of all termite families except the Serritermitidae
and includes certain of the fungus cultivators (subfamily Macrotermitinae). Many wood-
feeding termites include materials from more than one of the above categories in
their dietary range, sometimes even within a single colony (Lee and Wood, 197la).
The Australian rhinotermitid species Coptotermes acinaciformis , for example, attacks
a wide range of living and dead trees, predominantly Eucalyptus species (Calaby
and Gay, 1956), and dead wood lying on the ground; it is also a severe pest of timber
in buildings (Gay and Calaby, 1970). Tree species also differ widely in their attractive-
ness to termites because of differences in the chemical composition of the wood and
perhaps hardness (Waller and LaFage, 1987). Differences in wood quality may influence