COMPARATIVE STUDIES OF EGG PARASITOIDS OF ThaumeTopoea pITYoCampa AND T. solITarIa INHABITING A COMMON HABITAT IN THE EASTERN RHODOPES

The object of this study was to establish the similarity and interaction of egg parasitoidsof three generations (2009, 2010 and 2011) of Thaumetopoea pityocampaand T. solitaria inhabiting a common habitat in Dupkata protected area, near Ivaylovgrad (Eastern Rhodope Mountains, Southern Bulgaria). On T. pityocampa five egg parasitoidswere established, and on T. solitaria – three. With them, the similarity in the parasitoidcomplex is manifested in their two common parasitoids: Ooensyrtus pityocampae and Anastatus bifasciatus. The first one parasitized single eggs of T. solitaria, i.е. the reducing effect of pistachio processionary moth number is only 0.3%. The modification Ivlev’s electivity index showed that A. bifasciatus evinced certain preferences to T. pityocampa in the selection of host eggs for parasitization There was no substantial interdependence between the numbers of egg parasitoidsof both hosts. The number of O. pityocampae, as a parasitoidon T. solitaria, is too low to exert any influence on the number of the other host - T. pityocampa. Out of the parasitized eggs of the two hosts, with A. bifasciatus 99.6% male individuals emerged, i.e. the number of A. bifasciatus with both T. pityocampa and T. solitaria depends on the presence of the other alternative hosts for this parasitoidin the habitat under consideration.