Biology Reference
In-Depth Information
Subfamily
THELAXINAE
attacks on osiers grown for basket-making are of some
significance; rods may be stunted and the wood stained.
New growth may be killed, even when only lightly
infested.
Aphids with body flattened and eyes reduced to three
facets; antennae short, with a short terminal process,
siphunculi broad and cone-like, and cauda knob-like or
broadly rounded.
Pterocomma populeum
(Kaltenbach) (
175
)
A widely distributed aphid on poplar (
Populus
),
forming dense colonies on the young branches and
twigs. Damage caused, however, is slight. Apterae are
greyish green to greyish brown, with a pair of dark
spots on each body segment and a light covering of
whitish wax.
Glyphina betulae
(Linnaeus) (
177
)
Associated with birch (
Betula
), and often common
throughout the summer and autumn months. The dark
green, white-marked aphids cluster on the shoot tips and
young leaves, and often form dense colonies. Wingless
forms are 1.4-1.8 mm long, with short antennae, stout
legs, a rounded cauda and small, cone-like siphunculi,
and the body coated with short spine-like hairs; they
occur most commonly from June to the end of August
and again in October and November. Alates, which
appear from mid-June to late July, are dark green, with a
dark brown to blackish head and thorax; the abdomen
bears numerous tubercles and short, truncated siphunculi.
Pterocomma steinheili
(Mordvilko) (
176
)
Colonies of this species, which has a similar lifecycle to
that of
Pterocomma salicis
, occur on the young wood of
willow (
Salix
); the aphids are distinguished by their
reddish-brown to grey body colour.
175
176
175
Colony of
Pterocomma populeum
on
Populus
.
176
Colony of
Pterocomma steinheili
on
Salix
.
177
178
177
Colony of
Glyphina betulae
on
Betula
.
178
Colony of
Thelaxes dryophila
on
Quercus
.
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