Insects - Pests of Ornamental Trees, Shrubs and Flowers - page 82

167

breeds throughout the year. Colonies develop on the
young twigs and underside of the older branches, the
aphids often congregating in considerable numbers
within bark crevices and in other sheltered places. In
summer, colonies also occur on the roots. Apterae
(1.7-3.5 mm long) are reddish brown, with a purplish-
grey bloom and a pair of black bands extending from
the head to the siphunculi; the siphuncular cones are
indistinct and linked by a pair of curved, brownish
bands. The usually ant-attended aphids produce vast
quantities of honeydew, and affected hosts soon
become coated in sooty moulds. Infestations spoil the
appearance of ornamental trees and, if severe, result in
die-back of shoots and branches. 167 Colony of Cinara pruinosa on Picea .

Eulachnus agilis (Kaltenbach)
Narrow spotted pine aphid
A local pest of Scots pine ( Pinus sylvestris ); infestations
also occur on Corsican pine ( P. nigra var. maritima ).
Widely distributed in mainland Europe; in the British
Isles found mainly in southern England.

168

DESCRIPTION
Aptera: 2.2-2.9 mm long; body elongate and spindle-
shaped; bright green, with several reddish-brown dorsal
platelets, most bearing a short, pointed seta; antennae
short, pale greenish brown, the third segment with long
setae; siphuncular cones small; legs mainly light green,
the tibiae with long dark hairs.

168 Protective earthen canopy around colony of
Cinara pruinosa . LIFE HISTORY

Colonies build up rapidly during the spring, with both
winged and wingless forms present throughout much of
the year. Aphid numbers decline during the summer but
again reach a peak from late summer onwards. Sexual
forms are produced in the autumn and eggs are
deposited in the early winter, most placed singly on leaf
scars. Individuals arising from the eggs are very long-
lived and more prolific than those produced
parthenogenetically during the spring and summer.

Cinara pruinosa (Hartig) ( 167-168 )
Colonies of this large (2.4-5.0 mm long), dark green to
brown aphid occur on the shoots and branches of spruce
( Picea ) trees, especially Norway spruce ( P. abies ). The
rostrum is noticeably long, and the siphuncular cones
very large and prominent. In summer, colonies move to
the base of the trunk and to the roots, the winter being
passed as adults in the soil or as eggs on young twigs.
Colonies are ant-attended and often sheltered by earthen
canopies constructed by these insects.

DAMAGE
Needles in the vicinity of colonies become blackened,
following the development of sooty moulds. Heavy
infestations on nursery trees cause premature
defoliation, with significant losses of older needles.

Cinara tujafilina (del Guercio)
Thuja aphid
A widely distributed pest of Chilean incense cedar
( Austrocedrus chilensis ), Chinese thuja ( Thuja
orientalis ), white cedar ( T. occidentalis ) and certain
other Cupressaceae; present in central and southern
Europe, and in various other parts of the world. The
aphid is parthenogenetic and, in favourable situations,

Eulachnus brevipilosus Börner ( 169 )
Narrow green pine aphid
A widespread but generally uncommon species,
occurring mainly in pine-growing areas on the needles
of Scots pine ( Pinus sylvestris ). Austrian pine ( P. nigra
var. nigra ) and mountain pine ( P. mugo ) are also