A broad survey of the fall webworm (Lepidoptera: Erebidae) populations in agricultural and forested areas in the Central Black Sea Region of Turkey led to the detection of a granulovirus (GV). Hyphantria cunea granulovirus (HycuGV)-Hc1 isolate was characterized and tested against third instar larvae of H.cunea. Electron microscopy confirmed typical GV morphology with ovoid granules of approximately 368 +/- 16nmx201 +/- 19nm. Each granule contained a single rod-shaped virion with a mean size of 43 +/- 12nmx250 +/- 12nm. The genome was analyzed by restriction endonuclease and estimated to be approximate to 112kb. Partial sequencing of the granulin (gran), late expression factor-8 (lef-8) and late expression factor-9 (lef-9) genes also confirmed the identity of the virus as HycuGV. A phylogenetic analysis based on these conserved genes, HycuGV-Hc1 grouped together with the previous HycuGV isolate (A5-1) and Estigmene acrea granulovirus (EsacGV) isolate from the same family. The LC50 of HycuGV-Hc1 was 2.6x10(4) occlusion bodies (OBs/ml). Pot experiments, under field conditions, showed significant differences between virus treated and control groups. This is the first study to describe a novel Turkish HycuGV-Hc1 isolate, and preliminary data suggests that the virus has a significant potential as an effective biopesticide for control of H.cunea.