Biology Reference
In-Depth Information
1129
1130
1129
Eotetranychus carpini
damage to leaves of
Carpinus
.
1130
Lime mite (
Eotetranychus tiliarum
) damage to leaves of
Tilia
.
characteristic sign of an infestation) soon accumulate on
the trees. The foliage of infested trees is often
malformed and also becomes pale, silvery and brittle;
damaged leaves eventually turn brown and may fall
prematurely.
DAMAGE
Infested leaves become pallid, usually visible only from
below. However, heavy infestations may cause the
upper surface of leaves to become speckled with yellow.
Plant growth is not noticeably affected.
Eotetranychus fagi
(Zacher)
Beech red spider mite
This species occurs on beech (
Fagus sylvatica
) in
various parts of mainland Europe, including Belgium,
Germany, Italy, Poland and Switzerland; recently, the
mite has also been found in England. Infestations cause
extensive bronzing of foliage, and damage to nursery
stock and garden hedges is of particular concern.
NOTE
Oribatid mites (order Cryptostigmata), usually the
cherry beetle mite (
Humerobates rostrolamellatus
)
(a shiny, dark red to blackish, egg-like and short-legged
species about 1 mm long), often cluster in considerable
numbers on the bark of trees; they are harmless, feeding
mainly on algae and lichens, and should not be mistaken
for bryobia mites.
Eotetranychus carpini
(Oudemans) (
1129
)
Locally common on various trees, including maple
(
Acer
), alder (
Alnus
), common hazel (
Corylus
avellana
), hornbeam (
Carpinus betulus
), oak (
Quercus
)
and willow (
Salix
), and occasionally noted on cultivated
plants. In Europe most often reported in England,
Germany and the Netherlands; also present in North and
Central America.
Eotetranychus tiliarum
(Hermann) (
1130
)
Lime mite
A sporadically important pest of lime (
Tilia
),
particularly on established trees. Widely distributed in
Europe; also present in the eastern USA.
DESCRIPTION
Adult female:
0.4 mm long; yellowish to orange-red,
with red eyes and long, narrow dorsal setae.
Egg:
0.1 mm across; yellowish white and globular.
DESCRIPTION
Adult female:
0.4 mm long; light green or greenish
yellow, with red eyes.
Egg:
0.1 mm across; light green
and globular.
LIFE HISTORY
This species overwinters in the adult stage. In the
following spring the mites become active, invading the
newly developing leaves upon which eggs are laid. The
mites feed on the underside of the leaves, particularly
alongside the veins, young individuals passing through
larval, protonymphal and deutonymphal stages before
becoming adults. There are several overlapping
generations each year, populations reaching a peak from
late summer onwards. In the early autumn, female mites
LIFE HISTORY
Adult females hibernate on host plants in bark crevices
and other suitable shelter, reappearing in the following
spring. They then invade the underside of leaves to form
small, compact colonies. These are sheltered by often
dense, silken webs. Breeding continues from April to
October, and there are about six generations in a season.
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