pdf hard copy Apple blossom weevil (Anthonomus pomorum L. 1758 Coleoptera: Curculionidae) in Hungarian organic apple orchards and possible control methods PéTER SIPOS1 – ZSOLT MARCZALI1 – VIKTOR MARKó2 1University of Pannonia, Georgikon Faculty, Institute of Plant Protection, Keszthely, Deák Ferenc u. 57., 8360, Hungary sipos.peter86@gmail.com, marczali@georgikon.hu 2Corvinus University of Budapest, Faculty of Horticulture, Department of Entomology, Budapest, 1118 Ménesi út 44. Hungary Keywords: organic apple, apple blossom weevil, kaolin Organic apple production showing an increasing tendency worldwide, however, it still represents a relatively small section of the world’s apple market. A barrier of spreading organic production is the insufficient number of effective control methods, which are allowed in organic production. During the last few years, severe damages were found in organic apple orchards located in different regions of Hungary, which in some cases reached a drastic, 85% level. Organic growers could apply solely Bacillus thuringiensis var. tenebrionis entomopathogenic bacteria against this pest until 2011. From 2011, the spinosad active ingredient is also accepted in organic apple production in Hungary. From 2009 to 2011 kaolin clay (Surround WP) were tested in three different orchards, from the west to the northeast region of Hungary. The number of weevil adults was assessed by beating samples, while the infestation percent was evaluated by counting of infested buds. Kaolin showed significant effect only in some cases, while the effectiveness was low, around 50%. In 2011, the allowed three active ingredients (Bacillus thuringiensis var. tenebrionis, spinosad and kaolin) were tested in Western Hungary (Gutorf?lde, Zala county). We found out, when the pest pressure is high, only spinosad can provide effective control. From different experiments and from other non-treated areas from Central Hungary, infested buds were collected, when the pest was at pupal developmental stage to determine parasitism rate and the dominant parasitoid species. Between the different treatments, no differences were found on parasitism rate. From the total, 83% of the parasitoids were Scambus pomorum Ratzeburg 1848, which is the dominant parasitoid species of apple blossom weevil in Europe. Two specimens of Pnigalio vidanoi Navone 1999 were found, which species before was only recorded from Italy.