مرکز منطقه ای اطلاع رساني علوم و فناوري - RESEARCH ON DAMAGE RATE AND TYPE OF GREENSHIELDBUG (Palomena prasina L. HETEROPTERA: PENTATOMIDAE) ONHAZELNUT

Abstract :

This study was carried out to determine damage rate and damage types of P. prasina through cages experiments in hazelnut orchards in Samsun province in 2002 and 2003. For this aim, 125 and 150 shoots were caged with using cylindrical netting nylon cages in early April. In 2003 Damage rates and types of each nymphal stage (3 – 5 nymphal stage) were determined separately in addition to the experiments carried out in 2002. Damage type and damage ratio were evaluated separately for each period of nymph in 2003. One pair of P. prasina adult or nymph were released in treatment cages. No insect was released in control cages. Each cage was checked in every 3 days and when the insect death was observed, new insects introduced in cages. In harvest time the cages were removed and all the nuts were classified according to external (normal nut, dropped female flowers, prematurely dropped nuts that light brown in color and shrieked at the bottom, well-developed in size and grey-black in color nuts without kernel and underdeveloped nut) and internal peculiarities (normal kernel, blank, shriveled kernels and spotted kernel). As a result of statistical comparison only damage types that were different from those in control cages were considered. P. prasina caused only “prematurely dropped nuts that light brown in color and shrinked at the bottom type damage” (10.42 %) in external examinations in 2002. When developed hazelnut kernels were examined internally, spotted kernels (11.84 %) and blank nuts (9.48 %) were observed. The same experiment was repeated in 2003. In this year, “prematurely dropped nuts that light brown in color” and “shrinked at the bottom” type damages were 8.43 % and also “well-developed in size and grey-black in color nuts without kernel type damage” was also determined (2.52%), which was absent in previous year. In 2003, when well developed hazelnut kernels were checked, kernels were damaged as spotted kernels (9.58 %), blank nuts (6.98 %) and shriveled kernels (3.01 %).