Agriculture Reference
In-Depth Information
flat, oval and translucent.
Larva
up to 12 mm
long;
body
reddish (early instars whitish);
head
dark brown;
prothoracic plate and anal plate
light
brown with darker markings;
anal comb
present
but with a weakly sclerotized base (cf. that of
Pammene rhediella,
p. 222).
Pupa
6-7 mm long,
light brown.
tures just below the surface. The larvae then
pupate, and adult moths emerge about 2 weeks
later. There is just one generation annually.
DESCRIPTION
Adult
12-16 mm wingspan;
forewings
mainly
dark brown, suffused with grey, and marked with
several black dashes below the apex of the costa
and with several oblique whitish strigulae along
the costal margin, especially towards the tip
(Plate 12f);
hindwings
dark brown.
Egg
0.7 x
0.5 mm, flattened and oval; yellowish-white when
newly laid but each soon develops a pair of ir-
regular pinkish-red markings that disappear be-
fore hatching.
Larva
up to 14 mm long;
body
yellowish-white, often greenish-tinged;
pinacula
greyish
(Plate 12e);
head
yellowish-brown;
prothoracic plate
pale yellowish-brown, marked
with dark brown or blackish;
anal comb
absent.
Pupa
7-8 mm long, dark brown.
Cydia nigricana
(F.)
Pea moth
This widely distributed species is an important
pest of cultivated peas. The larvae bore into the
developing seeds
(Plate 12e),
and heavy infesta-
tions cause considerable losses to field crops and
to garden peas. The insect also attacks other cul-
tivated and wild Fabaceae. The extent of damage
within infested pods tends to be greatest in dry-
harvested peas, as these are harvested later in
the season, but significant damage rarely occurs
in early-sown peas due to be harvested before
July.
Cydia
pomonella
(L.)
Codling moth
BIOLOGY
Moths occur from late May or early June on-
wards, but are usually most numerous during
mid-July. They often congregate in suitable habi-
tats, and fly during the afternoon in warm, sunny
weather and in the evening. Eggs are laid mainly
on the underside of expanded leaves and stipules
of host plants, either singly or in small groups;
they are usually deposited on the upper half of
the plant and hatch about 8 days later. The young
larvae are very active and each crawls rapidly
over the host plant before locating a pod and
burrowing inside to attack the seeds. Each larva
feeds for several weeks and passes through five
instars. When fully grown, usually in August or
September, the larvae escape into the soil. Here
they overwinter, each in an oval (c. 10 x 4.5 mm),
thick-walled, silken cocoon incorporating parti-
cles of soil. Most cocoons are formed a few cen-
timetres below the surface but some occur at
much greater depths. In the following spring,
earlier or later depending on temperature, larvae
(but not necessarily all of those already close to
the surface) emerge from the cocoons and move
through the soil to spin feeble, web-like struc-
This notorious worldwide apple pest is often re-
sponsible for considerable fruit losses, especially
on unsprayed or infrequently sprayed trees. The
larvae (apple maggots) burrow singly into the
flesh of infested apples, filling the cavity with
brownish frass; larvae will also feed on the pips.
Infested fruits often have a distinct frass-filled
hole in the side, surrounded by a reddish ring;
sometimes, however, this hole occurs close to the
calyx (eye) and is then less obvious. Attacked
fruits ripen prematurely and often drop before
harvest. Damage is often particularly serious in
years when a noticeable second generation oc-
curs. Pear is also attacked. Codling moth larvae
occur later in the year and, therefore, in larger
fruits than those of the fruitlet-mining tortrix
moth,
Pammene rhediella
(p. 222) or apple
sawfly,
Hoplocampa testudinea
(p. 250). Also,
larvae of both other pests typically eject frass
from their galleries.
BIOLOGY
First-generation adults occur mainly from mid-
June to mid-July but, depending on the season,
