The effect of leaf feeder moth (Erannis defoliaria Operophtera brumata) on radial growth of 3 tree species in north of Iran (case study: Mashalak, Nowshahr)

In this study it has been considered that the inflict of two species, Erannis defoliaria and Operophtera brumata,decrease the radial growth of beech, maple and hornbeam in northern forests of Iran. 30 cores were prepared from each species and annual ring widths of them were measured. The results showed that in years 1998 and 1999, the growth of trees in the studied species considerably decreased when affected by O.brumata and E. defoliaria. By observing the moth in the year 1998, the radial growth decreased further more and reached to its minimum size when the loss was high. Maximum and minimum decrease in radial growth was observed in hornbeam and the maple, respectively.