Geoscience Reference
In-Depth Information
as 54 per cent of its records are from ant nests, especially of the yellow ant
Lasius-
flavus
whose influence on soil is described later. The nature of the association is un-
certain, but this little woodlouse may feed on ant faeces and so help to clean the nests.
M
ILLIPEDES AND CENTIPEDES
Most people can distinguish common millipedes, centipedes and woodlice by their
general body proportions and movement. It is surprising, therefore, to find that the
1981 Oxford Pocket Dictionary defines millepede
sic
as a “small, many-legged crawl-
ing animal: wood-louse.” Zoologists place millipedes and centipedes in the Myria-
poda while woodlice are grouped with shrimps and crabs in the Crustacea, so separ-
ating the two classes as distinctly as birds, mammals and reptiles among vertebrates.
In passing, we should mention two other relatively unfamiliar groups of small myri-
apods, the Pauropoda and Symphyla, though the glasshouse symphylid
Scutigerella
to a depth of two metres or more into the soil.
MILLIPEDES
There are 53 species of British millipedes of which five have been added in the past
fifteen years. They are predominantly animals of the forest floor and feed on plant
detritus including dead wood. Up to a dozen species have been found in oak wood-
land on limestone soils with densities of 350-650 a square metre, rising to 850 when
broods of young first appear. Fewer species inhabit base-deficient soils but here, in
the absence of earthworms, they sometimes play an important role in the breakdown
of plant matter, and produce characteristic moder humus through the accumulation of
their faecal pellets. Several species inhabit rough grassland or heathland, and only a
few true soil species occur in arable land. Manured soils encourage the build up of
populations of the spotted snake millipede
Blaniulus gutulatus
which can reach 1600
per square metre locally and do considerable damage to root crops.
