Agriculture Reference
In-Depth Information
will readily transfer from ploughed-up grasses to
young cereal plants, especially barley, oats and
wheat. Each larva also typically invades several
shoots during the course of its development.
DESCRIPTION
Adult
23-27 mm wingspan;
forewings
grey to
ochreous, more or less suffused with violet or
reddish-brown, and of variable appearance;
hindwings
mainly pale grey.
Larva
up to 25 mm
long;
body
dirty ochreous-yellow with a purplish
stripe along the back;
spiracles
black;
head and
prothoracic plate
blackish-brown.
BIOLOGY
The moths occur mainly in July and August, and
deposit their eggs on grasses and cereal plants.
The larvae feed from autumn onwards. They
typically burrow singly within the lowermost
f Ocm of a shoot, usually feeding with the head
directed downwards. As tissue is destroyed, and
the shoot becomes filled with frass, the larva in-
vades another shoot. Larvae are fully grown in
the following spring. They then pupate in the
soil, and the adults emerge several weeks later.
There is just one generation each year.
Noctua
pronuba
(L.)
Large yellow underwing moth
This widespread and generally common
'cutworm' attacks various vegetable crops, in-
cluding brassicas, carrot, celery, leek, lettuce,
onion, potato and red beet, especially in gardens
and allotments. On vegetable crops, the larvae
often bite out large cavities in the roots; minor
damage is also caused to other horticultural
crops, including strawberry. Unlike many other
'cutworm' species, the larvae frequently ascend
plants to feed on leaves and other aerial parts;
they are, therefore, referred to as 'climbing
cutworms'. Unlike turnip moth,
Agrotis segetum
(p. 234), this species is often damaging in cool,
damp summers.
DESCRIPTION
Adult
30mm wingspan;
forewings
brownish-
grey to dark brown, often with a pale reniform
stigma and paler areas along the hind i:argin
and between the stigma and the la; ral
margin;
hindwings
pale bi ownish-grey. Larva
up to 25 mm long;
body
pale green and shiny,
with a pair of often indistinct purplish-red ion-
gitudinal stripes along the back;
spiracles
dirty
whitish;
head
]_ale yellowish;
prothoracic plate
and anal plate
greenish to light brown
(Plate
15e).
BIOLOGY
Adults fly mainly from mid-June to August. Eggs
are laid in large batches on the leaves of various
plants and hatch about 3 weeks later. Larvae
occur from July onwards and most complete
their development in the following May. A few,
however, may develop more rapidly and produce
a partial second generation of adults in the au-
tumn. Pupation occurs in an earthen cell, without
forming a cocoon.
Mesoligea literosa
(Haworth)
Rosy minor moth
This widely distributed species is a minor pest of
cereals and grasses, especially in coastal areas.
However, attacks on field crops are rarely of sig-
nificance. The larvae feed within the plants
during the spring and early summer; the central
shoots of infested plants turn white or yellow and
eventually die.
DESCRIPTION
Adult
50-60 mm wingspan;
forewings
extremely
variable, ranging from yellowish-brown to dark
brown;
hindwings
dusky-yellow with a blackish-
brown border
(Fig. 325). Egg
hemispherical,
ribbed and reticulated, creamish-white to
purplish-grey.
Larva
up to 50 mm long;
body
plump but narrowed anteriorly; colour varies
from ochreous or brown to green, with a pale
BIOLOGY
Larvae feed from September to June within the
stems of cereals and grasses. When fully fed they
pupate in the soil. Adults fly in late July and
August.
