Biology Reference
In-Depth Information
71
72
71
Colony of small willow aphid (
Aphis farinosa
).
72
Ant-attended colony of small willow aphid (
Aphis
farinosa
) on
Salix
.
73
73
Colony of ivy aphid (
Aphis hederae
).
Aphis hederae
Kaltenbach (
73
)
Ivy aphid
This widespread and generally common, dark brown to
blackish aphid is most often associated with European
ivy (
Hedera helix
) growing on old walls and tree trunks,
infestations developing on the young leaves and shoots.
Colonies also develop on ornamental ivy plants and on
other cultivated Araliaceae. Although commonly
overwintering in the egg stage, live aphids will survive
the winter if conditions are favourable.
sexual forms appearing from June or July onwards. The
apterous viviparous females (1.7-2.3 mm long) are
mottled green and yellow, with mainly pale, moderately
long siphunculi. Males are characteristically reddish
orange and, owing to their coloration, nymphs of this
sex when developing within colonies are sometimes
mistaken for predatory midge larvae.
Aphis genistae
Scopoli
Genista aphid
Widely distributed but local on cultivated Spanish gorse
(
Genista hispanica
), forming dense, greyish colonies on
the shoots. Heavy infestations in summer weaken plants
and spoil their appearance. Apterae (1.4-2.6 mm long)
are blackish-bodied (lightened by greyish wax), with
relatively short siphunculi and an elongate cauda.
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