Research on Dreyfusia (Hom., Adelgidae) and its predators in Northern Turkey

In the East Pontic mountains at Giresun (Black Sea shore) three species of the genus Dreyfusia have been established: D. nordmannianae Eckst. and D. p relli Grosm, on Abies nord manniana Link. and Picea orientalis Link. and Dr eyfusia nov. spec, on A. nordmanniana. The latter species, earlier known fr om Greece and the Balkans, but not yet described is most probably unholocyc lic on fir. In the Zigana mountains between Trabzon and Gumusane a species producing pl enty galls on young P. orientalis trees and closely resembling D. merkeri E ichh. has been observed. Further investigations are necessary to evaluate w hether or not it lives unholocyclic on spruce. In the West Pontic mountains near Bolu D. nordmannianae was intensively stu died in twig infestations on A. bornmulle-riana Mattf. The pattern of attac k differs greatly from the one experienced in central Europe in that almost exclusively the current year's shoots are attacked whereas the leader and the older twig axis remain free of attack. In Europe all parts of the trees are colonized. Considering the known facts about generation- and morph sequences, morph de termination and phenological behaviour of D. nordmannianae the characterist ics of their population dynamics in Turkey and the interactions of the curi ous mode of attack and the extraordinary efficiency of their special predat ors have been completely evaluated.