Biology Reference
In-Depth Information
Family
ALEYRODIDAE
(whiteflies)
Aleurotuba jelinekii
(von Frauenfeld) (
57
)
Viburnum whitefly
This local, southerly distributed species occurs mainly
on
Viburnum rotundifolia
and
V. tinus
; it does not invade
other species of
Viburnum
but does occur on common
myrtle (
Myrtus communis
) and strawberry tree (
Arbutus
unedo
). Adults are 1.0-1.5 mm long, with whitish wings
and a yellowish-orange body. They occur mainly during
June and July, depositing eggs on the younger foliage.
Nymphs feed during the summer on the underside of the
leaves, and complete their development in the autumn
or following spring. The characteristic, scale-like
pseudo-pupae (1.0-1.5 mm long) are black, with a
whitish fringe and white waxen encrustations on the
body. They may be found throughout the winter and
spring, and are very conspicuous when infested leaves
are turned over. There is just one generation annually.
Attacks are relatively harmless but heavily infested
plants become contaminated with honeydew, upon
which sooty moulds develop.
Small, moth-like insects, coated with an opaque, white,
waxy powder. The nymphs are flat and scale-like.
Development includes a quiescent, non-feeding pupa-
like stage, known as a pseudo-pupa.
Aleurothrixus floccosus
(Maskell) (
56
)
Woolly whitefly
A polyphagous, subtropical pest of broad-leaved
evergreen plants, including ornamentals such as
Citrus
,
common fig (
Ficus carica
), fruiting myrtle (
Eugenia
)
and
Rhododendron
. Of South American origin, and
accidentally introduced into several other countries,
including southern Europe and the southern USA.
Adults are similar in appearance to other whiteflies but
have a yellowish tinge. Eggs are deposited on the
underside of leaves in characteristic circles or
semicircles and hatch shortly afterwards. The sedentary,
light green nymphs then develop rapidly, often forming
dense colonies. The nymphs excrete vast amounts of
rather viscous honeydew, and infested plants soon
become very sticky and blackened following the
development of sooty moulds. Third-instar nymphs also
secrete long waxen threads that persist throughout the
pseudo-pupal stage. As a result, colonies appear to be
covered by masses of cottonwool. In favourable
conditions breeding continues throughout the year, and
there are several overlapping generations annually.
Aleyrodes lonicerae
Walker
syn.
A. fragariae
Walker;
A. rubi
Signoret
Honeysuckle whitefly
Sometimes noted on ornamental honeysuckle
(
Lonicera
), snowberry (
Symphoricarpos rivularis
) and
many other plants, contaminating the foliage with sticky
honeydew upon which disfiguring sooty moulds
develop. Several overlapping generations occur each
year, the pale yellow, scale-like nymphs and the yellow-
bodied, white-winged adults mainly infest the underside
of expanded leaves. The adults are whitish, with a grey
spot on each fore wing.
56
57
56
Colony of woolly whitefly (
Aleurothrixus floccosus
).
57
Pseudopupa of viburnum whitefly (
Aleurotuba jelinekii
).
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