Agriculture Reference
In-Depth Information
Biston betularia
(L.)
Peppered moth
This species is a generally common pest of trees
and shrubs, including fruit crops, but is of most
significance on herbaceous ornamentals such as
chrysanthemum and pot marigold. The larvae can
cause noticeable defoliation but damage to trees
and shrubs is usually unimportant as the bulk of
feeding occurs relatively late in the season.
BIOLOGY
Larvae occur from July to September or October.
At night, they feed ravenously on the foliage;
during the daytime, they rest with the body held
straight out at an angle of about 45°, mimicking a
shoot or broken twig. Fully grown larvae enter
the soil to pupate, and adults emerge in the fol-
lowing year, usually in May, June or early July.
Fig. 307
Male peppered moth,
Biston betularia
(XLS).
DESCRIPTION
Adult
42-55 mm wingspan;
body and wings
white, peppered with black
(Fig. 307);
entirely
black (ab.
carbonaria)
and intermediate (ab.
insularia)
forms also occur;
antennae
in the male,
strongly bipectinated (Fig. 307).
Egg
0.7 x
0.5 mm, whitish-green.
Larva
up to 50 mm long;
brown or green, with pinkish markings;
spiracles
reddish;
body
stick-like, with a pair of dark pur-
plish prominences on the fifth abdominal seg-
ment;
head
purplish-brown with a distinct central
cleft
(Fig. 308)
.
Pupa
20-22 mm long; blackish-
brown,
cremaster
spike-like.
Erannis defoliaria
(Clerck)
Mottled umber moth
This moth is a generally common pest of decidu-
ous trees and is sometimes of importance in
orchards and in bush-fruit plantations.
Fig. 308
Larva of pepppered moth,
Bison betularia
(x2): (a) head (further enlarged).
BIOLOGY
Adults are active from mid-October onwards.
Eggs are eventually laid in crevices in the bark
of host plants and these hatch in the following
spring. Larvae feed from late March or early
April to June. When disturbed they drop from
the tree on a silken thread. Fully fed larvae enter
the soil where they eventually pupate.
DESCRIPTION
Adult female
f0-15 mm long, mainly ochreous-
yellow, mottled with black, and wingless
(Fig. 309). Adult male
35-38 mm wingspan:
forewings
extremely variable, usually pale yellow
to reddish-brown with darker markings:
hindwings
whitish-grey
(Fig. 310). Larva
up to
