Population densities and seasonal fluctuations of hazelnut pests in Samsun, Turkey

Abstract

Surveys conducted in hazelnut orchards in Samsun province during 1997-1998 showed that the most important and widespread pests were nut weevil (Curculio nucum), ambrosia beetle (Xyleborus dispar), big bud mites (Phytoptus avellanae and Cecidophyopsis vermiformis) and hazel longhorned beetle (Obera linearis). Pest populations varied over the four districts. Nut weevil adults appeared from early May to late June, and population density varied between 1-8 adults/10 "ocak". Carsamba and Salipazari districts had higher populations than the other two districts, and mean nut damage was nearly 14%. Big bud mites were widespread and were found in high populations. Big bud numbers varied from one to 7 per trunk, and Ondokuzmayis district had the highest population. Ambrosia beetle was a very serious problem in the Carsamba and Terme districts. Ambrosia beetle adults were seen in late April and early June. Hazel longhorned beetle produced very serious damage in Carsamba, Terme and Salipazari districts and numbers of injured twigs varied between 5-14 per "ocak". Pentatomid bugs (Hemiptera: Pentatomidae), fall webworm (Hyphantria cunea), filbert aphid (Myzocallis coryli), brown scale (Parthenolecanium corni, P. rufulum) and Gypsonema dealbana were found as secondary pests at varying population densities: