OPEN FIELD SURVEYS TO EVALUATE THE SUSCEPTIBILITY OF RED RASPBERRY GENOTYPES TO RASPBERRY GALL MIDGE, LASIOPTERA RUBI SCHRANK (DIPTERA, CECIDOMYIIDAE) - 4 YEAR RESULTS

The raspberry gall midge (RGM), Lasioptera rubi Schrank (Diptera, Cecidomyiidae) is an economically important pest, especially in the raspberry plantings where canes are not removed after harvest or are damaged mechanically under iter-row or intra-row cultivation, harvest or by hail. The objective of the study was to evaluate the impact of RGM in an untreated raspberry cultivar plantation (established in 2002) at the Fruit Research Institute, Serbia. The sampling was performed on five genotypes, cultivars ‘Willamette’, ‘Meeker’, ‘Latham’, ‘Tulameen’ and hybrid K 81-6. No galls were found in ‘Meeker’ from 2006 to 2008, in ‘Willamette’ and K 81-6 in 2007, in ‘Latham’ and in ‘Tulameen’ in 2009. Gals were found in ‘Tulameen’ only in 2008. The largest number of infested canes in 2006 and 2009 was found in K81-6 (16 and 51.1%), and in 2007 in ‘Latham’ (12.5%). A similar number of infested canes in 2008 was found on hybrid K 81-6 and in ‘Willamette’ which had 33 and 30% of canes infested, respectively. The highest larval pressure was found in ‘Tulameen’ (24.5 larvae per gall during 2008) and the least in ‘Willamette’ (4.5 larvae per gall during 2009).