Biology Reference
In-Depth Information
Family
BIBIONIDAE
(St Mark's flies)
Dilophus febrilis
(Linnaeus)
Fever fly
Larvae of this generally abundant bibionid also attack the
roots of young shrubs and trees, occurring in vast
numbers both in heavily manured soil and amongst
decaying vegetable matter. There are two, perhaps three,
generations annually. The larvae are relatively small, up
to 10 mm long; they are distinguished from those of
Bibio
spp. by the presence of three pores per anal spiracle.
Mainly black, hairy, robust-bodied, medium-sized to
large flies; males often hover sluggishly in the air in
conspicuous groups, with their noticeably long hind
legs dangling downwards. Larvae are cylindrical, with a
prominent head, well-developed mouthparts and fleshy
processes on each body segment; they often abound in
soil rich in organic matter.
Bibio
spp. (
366-367
)
Several species of bibionid fly, including
Bibio johannis
,
B. marci
and
B. nigriventris
, are reported as pests of
seedling trees, including conifers. Adults are slow-flying,
robust, black-bodied flies that often appear in vast swarms
during sunny days in the spring (e.g.
B. marci
) or early
summer (e.g.
B. johannis
). Eggs are deposited in groups in
the soil, particularly where there are accumulations of
organic material, the egg-laying females frequently being
attracted by decaying manure. The larvae occur in
considerable numbers in well-manured soil, feeding
indiscriminately on vegetative matter and often damaging
the roots of plants. They occur throughout the summer,
those of some species (e.g.
B. johannis
) overwintering and
completing their development in the spring. Bibionid
larvae are superficially similar in appearance to
leatherjackets but have a distinct black head and do not
exceed 20 mm in length; the body also bears several
fleshy papillae. In the genus
Bibio
, the anal spiracles each
have two pores (cf.
Dilophus
).
366
367
366
St Mark's fly (
Bibio marci
).
367
Larva of
Bibio johannis
.
Search WWH ::
Custom Search