Agriculture Reference
In-Depth Information
ground. At least in some areas, there may be a
second generation in the autumn.
3 mm long, with c. 9-pored anterior spiracles and
3-pored posterior spiracles.
DESCRIPTION
Adult
mainly brownish to black, with pale
squamae;
wings
2.5-3.1 mm long.
Larva
up to
3 mm long, whitish-yellow;
cephalopharyngeal
skeleton
with dorsal elements (dorsal cornu) (see
Fig. 107) divided into two;
posterior spiracles
3-
pored and located on relatively large, widely
spaced processes.
Cerodontha incisa
(Meigen)
This generally common leaf miner is a minor pest
of cereals and grasses. The larvae form relatively
large, whitish to yellowish galleries which extend
back from the tips of expanded leaves and even-
tually turn brown
(Plate 8c).
Infestations are
often noted on maize or sweet corn but tend to
occur on mature plants and are not important.
Agromyza nigrociliata
Hendel
BIOLOGY
Adults occur from spring onwards, and there are
two or more generations each year. Larvae feed
gregariously and pupate within the communal
mine, each puparium attached to the leaf tissue
by a few strands of silk.
This widely distributed but minor pest of cereals
and grasses has, on occasions, reached pest status
on rye and wheat. The larval mines appear from
early June onwards. They resemble those of
Agromyza nigrella
(above) but are usually
broader and typically contain several larvae.
Mined leaves become discoloured; heavy infesta-
tions of flag leaves on cereals are of most signifi-
cance. Adults (wings 2.9-3.5 mm long) are
mainly black with dark squamae. Larvae are
whitish-yellow and the puparia dark reddish-
brown.
DESCRIPTION
Adult
mainly black;
wings
2.3-2.8mm long.
Larva
up to 4 mm long, whitish;
mouth-hooks
with several small teeth;
posterior spiracles
borne
on a prominent cylindrical projection, and each
with three pores.
Puparium
2 mm long, metal-
lic-black;
posterior spiracles
located on a charac-
teristic projection
(Fig. 259).
Agromyza potentillae
(Kaltenbach)
larva
= Strawberry leaf miner
Liriomyza bryoniae
(Kaltenbach)
larva =
Tomato leaf miner
Minor infestations of this common and widely
distributed leaf miner often occur on cultivated
raspberry, strawberry and other Rosaceae, in-
cluding ornamentals such as cinquefoil. The leaf
mines commence as linear galleries. Each then
develops into an irregular, pale blotch, visible
from above. The mines are relatively small and
there are often several in each infested leaf or
leaflet. Although usually unimportant, heavy in-
festations on young strawberry plants can have
a detrimental effect on growth. Adults occur in
May or June and again in August; the larvae feed
from June to July and from September to Octo-
ber. Pupation occurs amongst rubbish on the
ground. Adults (c. 2 mm long) are black to
greyish-black. The larvae are whitish and up to
This leaf miner is a locally important pest of
glasshouse-grown tomato. Attacks also occur on
Fig. 259 Puparium of
Cerodontha incisa
(x20).
