Biology Reference
In-Depth Information
7
Stephanitis rhododendri
(Horváth) (
7-8
)
Rhododendron bug
A locally important pest of
Rhododendron
, especially
hybrids of
R. arboreum, R. campanulatum, R. campylo-
carpum, R. catawbiense
and
R. caucasicum
; probably of
North American origin. Infestations occur in various
parts of mainland Europe; also found in southern
England and Wales.
DESCRIPTION
Adult:
4 mm long; body brownish to blackish; wings
with a creamy, net-like venation.
Nymph:
yellowish,
ornamented with numerous brown spines.
7
Nymphs of rhododendron bug (
Stephanitis rhododendri
) and
damage on underside of leaf of
Rhododendron
.
LIFE HISTORY
Adult bugs first appear in June and may survive on host
plants until the early winter. Although fully winged,
they are relatively sedentary and do not fly. Once
established, therefore, infestations tend on individual
plants tend to persist. In the autumn, females deposit
eggs along the midrib of young leaves. These eggs
overwinter
in situ
, and eventually hatch in the spring.
Nymphs then feed on the underside of the leaves,
typically occurring in groups of up to 50 individuals.
There is a single generation annually.
8
DAMAGE
This pest causes a yellow mottling of the foliage, the
underside of damaged leaves developing a rusty-brown
appearance. Heavy attacks lead to extensive
discoloration of plants and may cause leaves to wilt.
Attacks are most severe on plants growing in sunny, dry
situations.
8
Rhododendron bug (
Stephanitis rhododendri
) damage to
upper surface of leaf of
Rhododendron
.
Stephanitis takeyai
Drake & Maa
Andromeda lace bug
This Japanese species has recently become established
in South East England on lily-of-the-valley bush (
Pieris
japonica
). It has also been found in parts of mainland
Europe, including Germany, Italy, the Netherlands and
Poland, and is a problem on ornamental Ericaceae in the
USA. Adults and nymphs cause mottling and bronzing
of leaves; severely damaged plants may die. The pest,
which overwinters in the egg stage, passes through five
nymphal stages and completes from two to four
generations annually.
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