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ŠUMARSKI LIST 7-8/2010 str. 81     <-- 81 -->        PDF

M. Glavendekić: PARASITOIDS AND HYPERPARASITOIDS OF ERANNIS DEFOLIARIACL. ... Šumarski list br. 7–8, CXXXIV (2010), 403-410


the parasitoid of A. marginaria caterpillar. In Forest
unitVisoka šuma Lošinci, compartment 22 it was reared
from the mottled umber moth caterpillar.


There are all together 16 parasitoid species recorded
onE. defoliariain oak forests in Serbia.The most frequent
species wasPhryxe nemea, which was recorded
at 6 localities. On four localities were recordedPhobocampe
pulchellaandPhryxe nemea.The highest diversity
of parasitoids was in Forest unit Mala Moštanica,
where 11 of 16 species were recorded. High diversity
of parasitoids was also found in pedunculate oak plantation
mixed with hornbeam in Forest unitVisoka šuma
Lošinci, where 50% of parasitoid species were recorded.
It is easy to distinguish parasitized caterpillars by
tachinide due to chorion on the front part of its body
and dark marking around it (figure 4).


Distribution and bioecology of mottled umber moth hyperparasitoids


Rasprostranjenje i bioekologija hiperparazitoida velikog mrazovca


During our study on hyperparasitoids ofE. defoliariain
oak forests following species were recorded:


Gelis areator Panzer, 1804 (Hymenoptera: Ichneu moni
dae) was found in two Forest units: Avala, Compartment
15, and Forest unit Kosovac as a hyperparasitoid of
mottled umber moth and winter moth caterpillars.


Bathythrix lamina Thomson, 1884 (Hymenoptera:
Ichneumonidae) was recorded in the Forest unitAvala.
It was reared from the cocoon Casinaria sp.(Hymenoptera,
Ichneumonidae) as a secondary parasitoid of


E.defoliaria.
Perilampus ruficornis(Fabricius, 1793) (Hymenop


tera: Perilampidae) was recorded in several Forest
units: Rađenovci, Compartment 4, from theTachinidae
cocoon; Forest unit, Mala Moštanica, Forest unit
Miroč, Compartment 73/74, from Tachinidae cocoon
reared from theE. defoliariacaterpillar.


Habrocytus chrysos Walker, 1836 (Hymenoptera:
Pteromalidae) was reared fromE.defoliariacaterpillar
originating from Forest unit Mala Moštanica.The host
died in the second instar.


Tetrastichussp.(Hymenoptera:Eulophidae) wasreared
from the several localities: Forest unit Mala Moštanica
– fromO. brumataandA. leucophaeariacaterpillars;
Forest unitVisoka šuma Lošinci, compartment 23 – from


O.brumatacaterpillars; Forest unitVisoka šuma Lošinci,
compartments 1 and 2 – from caterpillars ofA. aescularia,
A. leucophaearia,E. defoliariaandO. brumata.


Influence of parasitoids and hyperparasitoids on population dynamic of E. defoliaria


Uticaj parazitoida i hiperparazitoida na populacionu populacijsku dinamiku E. defoliaria


Population dynamics of parasitoids and hyperparasitoids
were studied in the culmination and in the first
years of the postculmination phase. Hyperparasitoids
fly before primary parasitoids.Their larvae were found
in the caterpillars before the primary parasitoid infected
the caterpillar. It is significant, however, that hyper-
parasitoids coincidence with primary parasitoid larva
was low compared to their frequency. In the phases of
retrogradation and latency, the coincidence was even
lower at some localities. Parasitoids and hiperparasitoids
are well adapted to their hosts. Locally they can
contribute to break down of the gradation.At the locality
Kožica we recorded the calamity of winter moths in
1992. Parsitism of mature caterpillars was 68.97%.The
presence of hyperparasitoids in them was only 6.9%,
the coincidence of parasitoids and hyperparasitoids
was 3.45%. In the following year, relative abundance
of winter moths decreased by half, but the percentage
of parasitized caterpillars remained very high – 37.5%.
The presence of hyperparasitoids was recorded in
15.63% of caterpillars and all of them coincided with
primary parasitoids.


Absolute parasitism of exposed caterpillars and
pupae was recorded on the locality Brankovac. In the
first postculmination year 64.51% of caterpillars were
parasitized.The hyperparasitoid larvae were present in
12.90% of caterpillars and the coincidence of parasitoids
and hyperparasitoids occurred only in 9.68% of
caterpillars.


In Forest unit Košutnjak in exposed conditions, the
abundance of parasitoids varied from 27.27% to
43.75%. Infestation of hyperparasitoids was very high
and it varied from 38.46% to 93.75%.The degree of
their coincidence, however, was not harmonised. The
highest percentage of caterpillars infected by parasitoid
and hyperparasitoid larvae was 31.25%, i.e. averagely
only 17.29% caterpillars.


The results of t-test (LSD), for the differences regarding
the time of sampling proves that there is no statistically
significant difference in parasitism depending
on the time of sampling of younger caterpillars.This
can be an important warning to the experts who plan
forest protection, especially if repressive measures of
control are applied. Suppression should be applied


th


against early instars of larvae (e.g. about 20 of April),
because in this way the natural potential of parasitoids
is going to be preserved.This depends of local climate,
elevation and specific ecological conditions.


To determine the level of egg parasitoids, the method
of exposing eggs was applied at many localities.
Thus egg parasitoidT. minutuswas identified at the lo


cality Miroč, compartments 73/74.Total parasitism of
winter moth eggs was 43.24%.Almost 30% ofO. brumataeggs
were parasitized.AlthoughE. defoliariawas