Biology Reference
In-Depth Information
68
67
67
Colony of cowpea aphid (
Aphis craccivora
) on
Robinia
.
68
Colony of
Aphis cytisorum
on
Laburnum
.
69
70
69
Colony of
Aphis cytisorum sarothamni
on
Cytisus
.
70
Aphis cytisorum sarothamni
damage to
Cytisus
.
Aphis craccivora
Koch (
67
)
Cowpea aphid
Uncommon in southern England but more numerous in
continental Europe, where it is associated with various
hosts, especially Fabaceae. The aphids are 1.4-2.0 mm
long and shiny black; nymphs are lightly dusted with
wax. Dense colonies often develop during the summer
on the young shoots of false acacia (
Robinia
pseudoacacia
), and infestations are often abundant on
such trees in towns and cities. In southern Europe this
aphid is an important pest of crops such as lucerne.
often abundant on established hosts, but are not of
economic importance.
Aphis cytisorum sarothamni
Franssen (
69-70
)
This subspecies is very similar to
Aphis cytisorum
but
occurs only on wild and cultivated broom (
Cytisus
),
affecting the leaves and developing pods. Cast skins
accumulate on host plants amongst excreted honeydew,
and are often more conspicuous on maturing pods than
the live aphids. Although widespread, this aphid is not
an important pest.
Aphis cytisorum
Hartig (
68
)
syn.
A. laburni
Kaltenbach
This greenish-black or blackish aphid infests the leaves
and developing pods of
Laburnum
and Spanish broom
(
Spartium junceum
). Colonies appear somewhat greyish
due to the presence of secreted wax. Infestations are
Aphis farinosa
Gmelin (
71-72
)
Small willow aphid
Dense ant-attended colonies of this widespread and
often abundant aphid occur on the young shoots of
willow (
Salix
), including ornamental cultivars.
Breeding continues from spring to mid-summer, with
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