Biology Reference
In-Depth Information
Subfamily
MINDARINAE
Tuberolachnus salignus
(Gmelin) (
173
)
Large willow aphid
An often common pest of willows, including almond
willow (
Salix triandra
), crack willow (
S. fragilis
), grey
willow (
S. cinerea
), osier (
S. viminalis
) and weeping
willow (
S. vitellina
var.
pendula
). Widely distributed,
particularly in central and southern Europe; in the
British Isles most numerous in southern England.
A small group of conifer-infesting aphids, with reduced,
ring-like siphunculi and a rather long cauda.
Mindarus abietinus
Koch
Balsam twig aphid
This light grey species forms small colonies during the
summer on the succulent new growth of fir (
Abies
)
trees. The aphids secrete considerable quantities of
waxen 'wool' and their feeding causes considerable
distortion of the foliage. Colonies are sometimes noted
on ornamentals but are usually of only minor
importance.
DESCRIPTION
Apterous female:
4.0-5.4 mm long; blackish brown,
with a large tubercle arising from the fourth abdominal
tergite; body clothed in fine, grey hairs.
LIFE HISTORY
Dense colonies of this large, conspicuous, long-legged
aphid occur on the branches and stems of willow trees
from late June onwards but not until much later in some
areas. Breeding is entirely parthenogenetic, with
populations reaching their maximum in the autumn. In
favourable areas, small numbers of apterae survive the
winter. Elsewhere, colonies must be re-established in
the following year by winged migrants that have been
reared further south. Colonies produce vast quantities of
honeydew and are constantly visited by sugar-seeking
insects such as ants, bees, wasps and various flies.
Mindarus obliquus
(Cholodkovsky)
Spruce twig aphid
Individuals of this species are small, elongate and white.
They occur throughout the summer on the tips of new
shoots of spruce (
Picea
) trees, and produce masses of
bluish-white waxen 'wool'.
Subfamily
PTEROCOMMATINAE
Relatively large aphids with terminal process of
antennae relatively short, siphunculi cylindrical to vase-
like (with or without an apical flange), and cauda
rounded to broadly tongue-shaped.
DAMAGE
The aphids weaken shoot growth, most significant
damage occurring on the canes of willows grown for
basket-making. Plants, including ornamentals, are also
contaminated by masses of sticky honeydew and sooty
moulds.
Pterocomma salicis
(Linnaeus) (
174
)
Black willow aphid
An often common pest of
Salix
, including crack willow
(
S. fragilis
), grey willow (
S. cinerea
), osier
(
S. viminalis
), pussy willow (
S. caprea
) and white
willow (
S. alba
). Holarctic. Present throughout Europe.
DESCRIPTION
Apterous female:
3.5-4.2 mm long; body dull
greyish black to black, with greyish or whitish
markings, and very hairy; antennae, legs and siphunculi
orange-red; antennae short; siphunculi flask-shaped.
Nymph:
pale orange-brown to greenish black, with
whitish markings.
174
LIFE HISTORY
Dense colonies often develop during the summer on the
shoots and young stems of host trees, and are commonly
attended by ants. The winter is spent in the egg stage in
crevices in the bark.
DAMAGE
Colonies on windbreaks and specimen trees or shrubs
are disfiguring but of little importance. However,
174
Colony of black willow aphid (
Pterocomma salicis
).
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