Biology Reference
In-Depth Information
Tuberculatus annulatus
(Hartig)
syn.
Tuberculoides annulatus
(Hartig)
Oak leaf aphid
Widespread and generally abundant on oak (
Quercus
),
especially English oak (
Q. robur
), the aphids
developing in scattered colonies along the major veins
on the underside of the expanded leaves. Infestations
often occur on young trees in parks, gardens and
nurseries but cause little or no damage, although
infested foliage may become contaminated by
honeydew and sooty moulds. The aphids (1.4-2.9 mm
long) have distinctively banded antennae, stumpy
siphunculi and a prominent, knob-like cauda; they vary
considerably in colour, being yellow, green, salmon-
pink or grey. Viviparous forms of this species, which
occur throughout the summer months, are all winged.
DESCRIPTION
Adult:
1.2-1.8 mm long; pale yellowish-green aphid,
with black markings on the body and wings, and a pair
of prominent black tubercles on the back.
LIFE HISTORY
This pest completes several generations annually and,
following a sexual phase, overwinters in the egg stage.
All adults, other than oviparae, are winged.
DAMAGE
Host trees are contaminated by honeydew and sooty
moulds. Although not causing deformation of foliage,
infestations result in premature leaf fall.
Takecallis arundicolens
(Clarke) (
134-135
)
Bamboo aphid
This eastern Asian species was accidentally introduced
into Europe, where it is now widely distributed and
sometimes locally abundant on bamboo (e.g.
Bambusa
and
Phyllostachys
). The aphids occur under the
expanded leaves but do not appear to be harmful. Adults
are medium-sized (1.8-2.8 mm long), whitish or pale
yellowish, with pale, dark-ringed antennae, short
siphunculi and a small, black, oval cauda. Nymphs are
pale with long, capitate body hairs, red eyes and the
joints of the antennal segments dark. Reproduction is
entirely parthenogenetic and all adults are vivparous
alates.
NOTE
Takecallis arundinariae
and
T. taiwanus
have also been
found on bamboo in Europe.
134
135
134
Bamboo aphid (
Takecallis arundicolens
).
135
Nymph of bamboo aphid (
Takecallis arundicolens
).
Search WWH ::
Custom Search