Page 21 - Volume 4, Issue 2, July 2011

© Benaki Phytopathological Institute
Karamaouna et al. 50
data of both parasitized size classes (ANO-
VA, F 1,31 = 15.04, P= 0.001) (Table 2).
Size of male wasps was related positive-
ly to a straight line with the host size (Linear
Regression ANOVA, F1,30 = 11.79, P= 0.002)
but the size of female wasps was not (ANO-
VA, F1,10 = 3.56, P= 0.088); however the fe-
male sample was low. In addition the re-
gression line coefficient (r 2) of the estimated
regression line for males (headwidth = 0.276
+ 0.016 x mumy size) was low (r2 = 0.282).
Discussion
The parasitoid Anagyrus sp. near pseudo-
cocci was recorded for the first time in
Greece and identified with accuracy using
a PCR-based technique. Varikou et al. (33)
have reported the presence of A. pseudo-
cocci in Crete and attributed effective bio-
logical control of P. ficus to the parasitoid in
organic vineyards. In addition there is only
one record of Anagyrus sp. on Planococcus
citri (Risso) (Hemiptera: Pseudococcidae) in
Greece (2).
The phylogenetic comparison of the se-
quences of Anagyrus sp. near pseudococ-
ci with those of A. dactylopii and A. pseudo-
cocci revealed that A . sp.near pseudococci
is genetically closer to A. dactylopii than to
A . pseudococci, an outcome fully congruent
with the conclusion of Triapitsyn et al. (31).
Anagyrus sp. near pseudococci seems
to prefer parasitizing female adults of the
vine mealybug P. ficus , larger than 1.6 mm,
whereas no successful parasitism is ob-
served in smaller mealybugs (0.5-1.5 mm).
Female adults (young and pre-oviposit-
ing) appear to be the most profitable host
stage of P. ficus for the development of A.
near pseudococci based on host preference
and successful parasitism. Laboratory ex-
periments by Daane and Bendley (10) with
the parasitoid A. pseudococci indicated also
a host size preference for larger hosts of the
mealybug P. ficus based on the parasitoid’s
attempts for oviposition in 2nd and 3rd instar
nymphs and female adults but successful
parasitism by A. pseudococci was not stud-
ied then. Gülec et al. (15) reported successful
parasitism of 3rd instar nymphs and young
female adults of P. ficus by A. pseudococci in
no-choice experiments, indicating that even
3rd instar nymphs provide adequate resourc-
es for successful parasitoid development.
Parasitoid fitness, in particular short-
er development time and larger size, of
Anagyrus sp. near pseudococci was not di-
rectly related with the host size at parasit-
ism. The development time of Anagyrus sp.
near pseudococci in young and pre-ovipos-
iting female adults of P. ficus was 16-17 days
(for female and male parasitoids, respective-
ly), which is comparable to the development
time of 15.2-16.6 days (for male and female
parasitoids, respectively) in A. pseudococ-
ci found by Gülec et al. (15) at the same
mealybug species and similar temperature
and photoperiod conditions (28 ± 1oC and
16L:8D). The host size at parasitism did not
affect the size of offspring of Anagyrus sp.
near pseudococci in either sex, which prob-
ably means that this is a koinobiont parasi-
toid like A. pseudococci (15).
Males and females of Anagyrus sp. near
pseudococci took similar time to develop in
our study whereas Gülec et al. (15) report-
ed that males of A. pseudococci developed
faster than females in young female adult
mealybugs. However, female parasitoids
emerging from hosts larger than 1.6 mm
were larger than male parasitoids emerg-
ing from the same host size class as it usu-
ally occurs in solitary Hymenoperan para-
sitoids of other mealybug species or other
insect pests (3, 19).
Should A. pseudococci and Anagyrus sp.
near pseudococci be biologically separate
species or not, the present preliminary host
size preference bioassay supports that both
of them have a preference for larger hosts of
the vine mealybug P. ficus.
We would like to thank Dr John Noyes (Natural
History Museum, U.K.) for the identification of
the parasitoid samples and the valuable com-
ments on the systematic taxonomy of the spe-
cies.