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SEXTON BEETLES
The Burying or Sexton Beetles are a curious and
striking group of large black or black and orange
beetles which are sufficiently well known to have
gained English names. They can be easily found
by examining old carcases of fish, rabbits, mice
or less commonly on old fungi, and I have
occasionally taken them in my Mercury Vapour
light trap, as they fly well and can detect
carrion from a long distance.
Most insects fend for themselves as larvae,
their parents having simply deposited their eggs
and moved on or died, but there are notable
exceptions, e.g. the social insects, the ants,
bees, wasps and termites which are well known
to look after their young. It is less well
known that some beetles also care for their
young, and the Sexton Beetles are among this
group.
When the male beetle detects a suitable carcass
e.g. of a mouse, he examines it thoroughly,
checks that the ground below it is soft enough
to bury the mouse in, and if his requirements
are met, he signals for a mate, if one has not
already arrived. This he does by tilting his
rear upwards and emitting his pheromone or
sex hormone, for several hours if need be, until
a female arrives. If two females should arrive
together there is then a fight until one female
has driven away the other.
After mating, the insects begin to bury the
carcass by removing the soil, grass, leaves
etc from around it using their strong jaws
and spined tibiae.
The pair excavate the ground below the cadaver
and it slowly sinks below ground level. The