Agriculture Reference
In-Depth Information
either fall to the ground or keel over and wither
whilst remaining temporarily suspended by a
piece of rind. Damage to young trees is some-
times severe but attacks on established trees are
of little or no significance.
BIOLOGY
Adults occur from May onwards and are espe-
cially active in warm, sunny weather when they
fed on the foliage of apple trees and other hosts.
Eggs are deposited in early June, each inserted in
a young vegetative shoot, a few centimetres from
the tip. The egg-laying female then severs the
shoot just below the point of oviposition. Larvae
feed within the shoots for up to 4 weeks and then
escape to pupate, each in a small cell formed
a few centimetres below the surface of the
soil. New adults appear towards the end of the
summer and eventually hibernate.
Fig. 224
Apple fruit rhynchites weevil,
Rhynchites
aequatus
(x20).
DESCRIPTION
Adult
2.5-4.5 mm long, relatively broad-bodied
and shiny metallic blue, clothed with black
hairs.
Egg
oval and translucent.
Larva
3-
4 mm long;
body
whitish;
head
brownish.
foliage of strawberry and various
Rubus
hosts.
They also damage the blossoms and other veg-
etative tissue. On strawberry, eggs are deposited
in holes made in the petioles, in the stalks of the
blossom trusses and in the tips of the stolons,
often in small groups of up to four (cf. strawberry
blossom weevil,
Anthonomus rubi,
p. 154). Tis-
sue beyond an oviposition point, within which
the larvae feed, withers and dies. Larvae feed for
a few weeks and, when fully grown, pupate in the
soil. The adult stage is reached a few weeks later.
Individuals, however, remain
in situ,
and do not
emerge until the following spring. Adults are 2-
3 mm long and black with a greenish-blue sheen;
they are readily distinguished from those of
A.
rubi
(p. 154) by the antennae, which lack a scape.
Rhynchites aequatus
(L.)
Apple fruit rhynchites
This locally distributed species is a minor pest on
fruit trees, especially apple. The adults some-
times attack buds in the spring but cause most
damage by drilling large numbers of small, cylin-
drical holes into developing fruitlets. Eggs are
laid singly at the base of some of these holes.
Larvae later feed on the flesh for a period of
about 3 weeks. Fully fed larvae eventually
pupate in the soil. Adults are 2.5-4.5 mm long
(Fig. 224)
and purplish to bronzy with reddish-
brown elytra.
Family APIONIDAE
Apion trifolii
(L.)
Clover seed weevil
Rhynchites germanicus
Herbst
Strawberry rhynchites
This weevil is a local pest of strawberry; attacks
also occur on cane fruits. Adults become active
in the early spring. They then feed on the young
This weevil is an often common pest of clover,
especially red clover. The adults make small
rounded or elongate holes in the foliage and
