Biology Reference
In-Depth Information
Family MEGACHILIDAE
LIFE HISTORY
Adults appear in March and April. They are active in
warm, sunny weather, and then forage on various spring
flowers. Mated females excavate deep (15-30 cm long)
burrows in the soil, the excavated soil forming volcano-
like mounds on the surface. Each burrow consists of a
main tunnel, with a cell at the bottom, and a series of short,
lateral branches, each also ending in a single cell. Into
each cell the female places a quantity of nectar and pollen,
upon which she then lays an egg; when all the cells have
been provisioned, she seals the burrow with soil and flies
away. After the eggs have hatched, the entombed larvae
feed on their supplies of food; fully fed larvae eventually
pupate, and adult bees emerge in the following spring.
Megachile centuncularis (Linnaeus) ( 1070 )
Common leaf-cutter bee
Generally common, the adult females sometimes
damaging the leaves of rose ( Rosa ) and other
ornamental plants, including Laburnum , lilac ( Syringa ),
privet ( Ligustrum vulgare ), Rhododendron and snowy
mespilus ( Amelanchier laevis ); petals of Geranium
plants are also damaged. Widely distributed in Europe.
DESCRIPTION
Adult female: 10-12 mm long; black bodied; head and
thorax clothed in golden-brown hairs; abdomen clothed
above with black hairs but banded with pale hairs,
particularly basally; pollen-collecting hairs on
underside of abdomen orange-red and projecting
beyond the sides to form an apparent fringe; legs with
pale hairs; wings smoky.
DAMAGE
Heaps of excavated soil are a nuisance when fine
lawns are invaded by large numbers of bees attracted
by particularly favourable nesting conditions.
LIFE HISTORY
Adults are active in June and July. They occur
commonly in gardens, foraging during the daytime on
various flowers from which they collect both nectar and
pollen. When ready to breed, the females form elongate
burrows in decaying wood, soft brickwork or light soil;
each then collects several fresh leaf fragments from
nearby rose bushes or other suitable plants, and carries
these into her burrow to form a series of thimble-like
brood cells. When completed, each cell is provisioned
with a mixture of nectar and pollen, and an egg
deposited on the surface. The cell is then capped with a
leaf fragment and another cell constructed above it.
A fully furnished nest usually contains a series of about
six cells placed end to end; the burrow is then sealed
with wood-pulp or soil and abandoned. Larvae feed on
their store of food from late summer onwards. They
complete their development in the following spring and
then pupate.
1070
DAMAGE
Attacked leaves have large, regular, oblong or
semicircular pieces removed from the blade. Such
damage often causes concern. However, although plants
are disfigured, growth is not affected.
1070 Common leaf-cutter bee ( Megachile centuncularis )
damage to leaves of Rosa .
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