Agriculture Reference
In-Depth Information
with oats. The larvae cause infested nodes to
become swollen but damage is insignificant and
the insect is not of economic importance.
and Scotland. Occasionally, attacks also occur on
loganberry. The larvae may be found beneath
the rind of the new canes, immediately adjacent
to growth splits. The feeding sites eventually
turn brown or black but direct damage is usually
of only minor importance. More significantly,
midge-damaged canes are often infected by fun-
gal pathogens; this results in a disease known as
'midge blight', and this may lead to the death of
canes ('cane blight'). Midge damage is especially
severe on cultivars with freely splitting canes
(e.g. Glen Clova, Mailing Enterprise and Mailing
Promise) and, where 'midge blight' develops,
crop yields in the following season may be re-
duced considerably.
Mayetiola dactylidis
Kieffer
Cocksfoot stem midge
Infestations of this univoltine species occur on
wild and cultivated cocksfoot, but are not consid-
ered of any great significance.
Mycophila barnesi
Edwards
A mushroom midge
Larvae of this widely distributed midge are or-
ange and occur commonly in cultivated mush-
room beds, often in their thousands. Each
'mother' larva reaches about 2 mm in length and
produces up to 20 'daughter' larvae in just over
a week. Unlike larvae of the mushroom cecid,
Heteropeza pygmaea
(p. 176), the gut contents
are voided at intervals throughout larval devel-
opment, and breakdown of mushrooms through
bacterial action does not occur; also, there is no
clumping behaviour and no resting stage in the
life-cycle, individuals dying if starved of food.
Attacks by this species, which has a slower rate
of development than either
H. pygmaea
or
Mycophila speyeri
(below), tend to be limited to
the third and later flushes of mushrooms.
BIOLOGY
Adult midges appear from early May onwards
but the time of appearance varies by several days
to a few weeks, depending on local tempera-
tures. Eggs are deposited in breaks in new rasp-
berry canes and hatch in about a week. The
larvae feed gregariously beneath the rind for up
to 3 weeks and then drop to the ground to spin
silken cocoons in the soil. Second-generation
adults emerge 2-3 weeks later. There are usually
three overlapping generations each year and lar-
val populations tend to increase markedly as the
season progresses; in late summer and autumn,
there may be several hundred larvae feeding on
any one infested cane. Fully grown larvae of the
autumn generation overwinter in their cocoons
and pupate in the spring.
Mycophila speyeri
(Barnes)
A mushroom midge
DESCRIPTION
Adult
2.0 mm long, dark reddish-brown.
Egg
minute, sausage-shaped, translucent.
Larva
up
to 3.5 mm long, translucent when young but soon
becoming yellowish-orange to salmon-pink.
This species develops more rapidly than
Mycophila barnesi
(above), and the bright or-
ange 'mother' larvae each produce about 20
'daughter' larvae in less than a week; the larvae
often contaminate mushroom crops from the
first flush onwards.
Resseliella oculiperda
(Riibsaamen)
larva =
Red bud borer
Resseliella theobaldi
(Barnes)
Raspberry cane midge
This widely distributed but local midge is a po-
tentially important pest of rose. The larvae cause
damage to budded stocks and grafts; a similarly
damaging 'strain' also occurs on fruit trees
(Rosaceae), particularly apple. Affected buds or
The raspberry cane midge is a widespread and
locally important pest of raspberry, particularly
in the main raspberry-growing areas of England
