Page 14 - Volume 6, Issue 1, January 2013

© Benaki Phytopathological Institute
Kapaxidi 12
Ozman Sullivan (2006) evaluated the bi-
ology of the phytoseiid K. aberrans, a possi-
ble predator of the big bud mite P. avellanae,
which is a common pest in Greek hazelnut
orchards, and concluded that K. aberrans can
play an important role in IPM programmes
to control P. avellanae when it is released in
early spring to boost the population before
P. avellanae migration.
In olive groves, predatory species of Phy-
toseiidae comprise A. andersoni, T. (A.) ath-
enas, Typhlodromus (Anthoseius) foenilis
Oudemans, Typhlodromus (Typhlodromus)
cotoneastri Wainstein and K. aberrans (Pa-
paioannou-Souliotis et al., 1994; Papadoulis
et al., 2009). Euseius stipulatus, K. aberrans, E.
finlandicus and Phytoseius plumifer (Canestri-
ni and Fanzago) are the most common spe-
cies found on fig trees (Papaioannou-Souli-
otis et al., 1994).
On pomegranate, the following phyto-
seiid species have been reported T. (A.) ath-
enas, Typhlodromus (Anthoseius) psyllakisi
Swirski and Ragusa, T. ( T.) athiasae (Papadou-
lis et al., 2009). Koveos et al. (2010) found an
unidentified stigmaeid mite in association
with A. granati on pomegranate.
On grapevine, the most common and
abundant species of Phytoseiidae are K. ab-
errans, E. finlandicus, P. plumifer, T. (A.) athe-
nas, T. (T.) exhilaratus and P. talbii, (Soulioti et
al. , 1998; Papadoulis et al., 2009). The stig-
maeid mites Zetzellia graeciana Gonzalez
and Z. mali have also been reported (Papa-
ioannou-Souliotis et al. , 1994).
Monitoring
Monitoring eriophioidmites is a difficult task
due to their minute size (average 100 μ) and
concealed way of life. The presence of erio-
phyoids is usually transpicuous when the
symptoms become apparent. In the case of
rust mites, monitoring involves collection of
leaves or fruits and counting the number of
mites. To assess populations, leaves should
be examined with a hand lens with at least
10x magnification. Although it is impractical
to obtain accurate population counts with
this method, if many individuals are noticed,
more intensive sampling should be consid-
ered, ideally with a dissecting microscope.
Hall et al. (2005, 2007) investigated the ef-
fects of reducing the sample size on the ac-
curacy of estimation of citrus rust mite den-
sities in oranges and proposed a binomial
sampling based on the proportion of erio-
phyoid infested samples.
Chemical Control
In general, eriophyoid mites prove to be fair-
ly susceptible to the most commonly used
acaricides, as was demonstrated by Childers
et al. (1996) who made a thorough review of
the chemical control of eriophyoids. Since
then there have been changes to registered
acaricides mostly in Europe, and most of the
substances tested are no longer in use. How-
ever, a rather limited amount of reports has
investigated the suitability of modern crop
protection compounds for controlling rust,
gall, blister and bud mites. Moreover, these
reports are mainly restricted to a number of
major crops like citrus and apple orchards
and major pests as P. oleivora and A. schlech-
tendali, respectively. The main reason for the
lack of information on the toxicity and other
aspects of new compounds can be probably
brought back to the lower economic impor-
tance of these mites, in comparison to oth-
er mite pests such as the spider mites (Acari:
Tetranychidae).
In Greece, there are no thresholds for
the damage caused by eriophyoid mites.
The usual practice is acaricide or sulfur treat-
ment when the infestation is evident to af-
fect the trees’ vigor or yield. Registered ac-
aricides (active substances) for control of
mites in orchards and grapevine are given
in Table 2.
The usual practice for the management
of A. phloeocoptes and A. fokeui in stone fruit
orchards is application of selective acari-
cides. For A. phloeocoptes application time is
in early spring (March) at the opening of the
buds when the mites are migrating to new
buds while for A. fokeui it is in summer (Pa-