Page 17 - Volume 4, Issue 2, July 2011

© Benaki Phytopathological Institute
Karamaouna et al. 46
of the pest (15, 16).
Anagyrus pseudococci is reported as a
native endoparasitoid in many countries in-
cluding, Argentina, Israel, Italy, South Afri-
ca and Turkey bu Gülek et al. (15) but mor-
phological and molecular studies as well as
cross-breeding experiments in cultures dif-
ferent origin which were originally consid-
ered as P. pseudococci revealed two distinct
taxonomic forms: Anagyrus sp. near pseudo-
cocci and A. pseudococci (31).
Anagyrus sp. near pseudococci is a main-
ly Palearctic species, common in the Med-
itterranean region, which has also been es-
tablished after introduction in California (31).
Anagyrus pseudococci is considered aslo of
Palearctic origin, believed to have been in-
intentioanally introduced in Argentina with
seedlings from Italy (31). Both species coexist
in Sicily. Anagyrus sp. near pseudococci resem-
bles with A. pseudococci and the only mor-
phological feature that discriminates them
is found in the antennae: the first antennal
funicle segment of female is partially black
(basal half or so) and white (distal half or so)
in A. pseudococci whereas it is entirely black
in A. sp. near pseudococci (31). However, it is
generally admitted that the subtle morpho-
logical differences between A. pseudococci
and A. sp. near pseudococci, can sometimes
be misleading (Noyes, personal communi-
cation), and thus only an expert could distin-
guish between them. DNA barcoding, based
on a sequence from the Cytochrome Oxidase
One (COXI) mitochondrial gene, has assisted
in the resolution of various biological queries,
ranging from detection of intraspecific varia-
tion to cryptic species recognition (4, 5, 26, 27,
28) and therefore could apply for the genetic
identification of A. sp. near pseudococci.
Host preference has been defined as
the relative frequency of host types chosen
for parasitism compared with the frequen-
cy of host types available (18). Host stage or
host size selection behaviour within a patch
may be related to several factors such as dif-
ferences in the profitability of each develop-
mental stage e.g. small hosts may not provide
adequate amounts of resource to support
the successful development of parasitoid off-
spring (idiobionts) or can only produce small
parasitoids in size which consequently reduc-
es components of fitness such as longevity,
fecundity and searching efficiency (idiobionts
and koinobionts) (1). Small host size is often
associated with lengthened development
and/or reduced survival (14).
In the present work, the incidenece of
the parasitoid A. sp. near pseudococci was
proved from genetically identified samples
in Greece. Moreover, the host size prefer-
ence for the vine mealybug P. ficus and the
effect of host size on development time and
size of the parasitoid offspring were investi-
gated as indices of the parasitoid fitness.
Materials and methods
Anagyrus sp. near pseudococci identifi-
cation
The parasitoid samples were collected
as parasitized mealybugs on Mentha spp.
(Lamiaceae) at the region of Κifissia- Ath-
ens, Greece. The parasitoid species was first
identified as Anagyrus sp ., presumably A. sp.
near pseudococci versus Anagyrus pseudococ-
ci (Girault) (Karamaouna, personal commu-
nication) based on morphological features
(24, 31). Samples of both sexes of the para-
sitoid were sent to Dr John Noyes (Natural
History Museum in the U.K.) for the system-
atic taxonomy of the species and they were
identified as Anagyrus sp. of the pseudococ-
ci complex, which includes both A. dacty-
lopii and A. pseudococci, sensu stricto and
the so-called “Israeli” strain (Noyes, person-
al communication).
Molecular techniques were used for the
verification of the sampled species. Insect
DNA was extracted using the GenEluteTM
100 Kit (Sigma) following the protocol of the
manufacturer. An amplicon of about 900 bp
from the mitochondrial COI gene was po-
lymerised in 25μl reactions containing 1.5
mM MgCl2, 50 M dNTPs, 0.2 _M of the prim-
ers MTDNA04 (forward) (AGGAAC(AT)GG(AG)
TGAACNGTTTA(TC)CC(AT)CC) (Avtzis, Nav-
rozidis and Tsoktourides, unpublished data)
and UEA10 (reverse) (22), and 1U of Taq poly-