Page 9 - Volume 6, Issue 1, January 2013

© Benaki Phytopathological Institute
Eriophyoids in Greek orchards and grapevine 7
vein but as attack develops they cover most
of leaf surface. Badly infested leaves die and
fall off. It also damages the fruitlets and fruit
stalks, which may drop prematurely.
Eriophyoids of Citrus
Aceria sheldoni (Ewing) [Eriophyes shel-
doni Ewing]
Common name: citrus bud mite
Damage: The citrus bud mite feeds within
the buds causing variable symptoms such
as distortion of shoot growth, excessive and
grotesque deformation of fruit, foliage, and
blossoms, discoloration of fruit, and more
commonly the production of numerous
buds. The last may develop abortive twigs in
tight clusters resembling “witches broom”
and bunged terminal growth of distorted
stems and leaves. Most malformed fruits
drop prematurely. Mature lemon fruits show
blackened areas on the rind beneath the se-
pals (buttons), where large colonies of mites
are concealed. Deformed leaves and blos-
soms have various shapes; the leaf plates are
constricted at their middle, curled, twisted,
divided and divergent at the tips; the blos-
soms are stunted and abnormal. The symp-
toms of injury on oranges are similar to
those on lemons except fruit deformation is
not so grotesque. Affected oranges usually
develop to maturity, but they are common-
ly flattened, resembling the shape of toma-
toes; or they are skinfolds, seams and ridges,
or small apertures in the stylar end.
Aceria sheldoni has been found in all
Greek citrus-growing regions, causing dam-
age mainly in lemons, which can be signifi-
cant only during years with high population
levels (Papaioannou-Souliotis, 1985; Papaio-
annou-Souliotis et al., 1999).
Aculops pelekassi (Keifer) [Aculus peleka-
ssi Keifer, Vasates pelekassi (Keifer)]
Common name: pink citrus rust mite
Damage: Pink rust mites not only cause rus-
seting of fruit and leaves, but also mild to
severe distortion of new growth, brown le-
sions on lower surfaces and along midribs
of immature leaves, and may produce mes-
ophyll collapse, chlorosis, and leaf drop. It is
potentially capable of causing more dam-
age to its host than citrus rust mite Phyllo-
coptruta oleivora (Jeppson et al., 1975).
Aculops pelekassi was first found in
Greece in 1958 and since then its presence is
frequent all over the country (Papaioannou-
Souliotis, 1985; Papaioannou-Souliotis et al.,
1994). It is active during mild winters and
can develop more than five generations per
year. In population outbreaks it can cause
up to 60% loss of yield (Papaioannou-Souli-
otis, 1985).
Phyllocoptruta oleivora (Ashmead)
Common name: citrus rust mite
Damage: Its feeding destroys the epidermal
cells of the rind, producing silvering or rus-
set effects. The ring of the affected fruit is
thicker than normal, and the fruit tends to
be smaller. Another result of the infestations
on lemons and grapefruit is a condition
known as “shark skin”, in which the outer
layer of the skin can be peeled. Heavy popu-
lations of mites feeding on leaves and twigs
can also cause bronzing.
Greek citrus orchards are mainly infest-
ed by A. pelekassi and A. sheldoni, which can
cause serious damage on fruit production
when outbreaks of their population occur
(Papaioannou-Souliotis, 1985, 1991, 1996;
Papaioannou-Souliotis et al. , 1992). P. oleivo-
ra only occur in limited part of orchards (Pa-
paioannou-Souliotis et al. , 1994).
Eriophyoids of Nut trees
Aceria erineus (Nalepa) [Phytoptus tristri-
atus var. erineus Nalepa, Eriophyes tris-
triatus var. erineus (Nalepa), Eriophyes
erineus (Nalepa)]
Common name: persian walnut erineum
mite
Damage: The infestation caused by this mite
is most noticeable as shiny convex swellings
on the upper surface of the leaf blade and on
the underside as patches of shallow, large,
solitary concavities lined with felty, yellow-
ish hairs, among which the mites are found.
These patches have well defined edges and