Biology Reference
In-Depth Information
106
(
Artemisia
). The aphids are dark reddish brown, partly
coated in white wax that forms an attractive and
characteristic pattern; the siphunculi and cauda are
black. On pale, silvery-looking host plants the dark
appearance of the aphids contrasts with the foliage,
and colonies are very noticeable; the aphids are ant-
attended.
Macrosiphoniella oblonga
(Mordvilko)
This widely distributed species occurs throughout the
year on protected
Chrysanthemum
, but may also
overwinter in the egg stage at the base of plant stems.
The aphids feed singly on the underside of older leaves
and on the flower stalks. They are easily dislodged from
host plants, dropping to the ground if disturbed. In
addition to
Chrysanthemum
, infestations occur
commonly outdoors on wild hosts such as scentless
mayweed (
Tripleurospermum maritimum
). The aphids
are 5 mm long, slender-bodied, green to light green, with
a darker dorsal longitudinal stripe; the legs are very long
and thin, the siphunculi broad and moderately long but
without an apical flange; the cauda is blunt and about
as long as the siphunculi. Apterous males are reddish
brown, with a relatively small body and long legs.
106
Colony of
Macrosiphoniella absinthii
on
Artemisia
.
107
Macrosiphum albifrons
Essig (
107-108
)
Essig's lupin aphid
An important North American pest of lupin (
Lupinus
).
In Europe, first reported in 1981, in southern England;
now widely distributed and spreading within mainland
Europe.
107
Apterous female and nymphs of Essig's lupin aphid
(
Macrosiphum albifrons
).
DESCRIPTION
Apterous female:
3.2-4.5 mm long; large, light bluish
green, with a white, waxy coating; antennae, legs,
siphunculi and cauda all long; siphunculi light brown,
with darker tips.
Alate:
3.2-4.5 mm long; similar to
aptera but the siphunculi entirely dark.
Nymph:
similar
to adult.
108
LIFE HISTORY
Breeding colonies develop on all parts of host plants,
including flower spikes, roots, pods and senescing
tissue. The reproductive rate is high and colonies build
up quickly. Infestations spread rapidly during the
summer, following the production of winged forms.
Aphids overwinter in the crowns of mature plants.
108
Colony of Essig's lupin aphid (
Macrosiphum albifrons
)
on
Lupinus
.
DAMAGE
Severest damage is caused to young flowers, with whole
spikelets being aborted. Plants may be killed if
infestations are heavy.
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