Interactions between Ophiostomatoid Fungi and Scolytid Bark Beetles in Korea

摘要

Scolytid bark beetles(Coleoptera: Scolytidae), which are known to be associated with blue stain fungi(BSF) causing sap-stain in trees or freshly cut logs, were collected from the trap logs of different pine species; Pinus. rigida, and Finns, koraiensis every week from April to July. Among 10 species of bark beetles collected, Hylurgops interstitialis was the most common species from P. koraiensis, while Tomicus pint perdu was the most common from P. rigida population of Hylurgops. interstitialis was the highest in May, while that of T. piniperdu was the highest in April. In the early June, new adults from pupae started to emerge. In order to study ecological relationships between populations of bark beetles and isolation frequency of BSF, fungi were isolated from adults, eggs/larvae, and galleries of bark beetles on the selective media. Isolation frequency of BSF from o-verwintered adults and galleries was 100% and 94%, respectively. However, those from spawned eggs or hatched larvae were relatively low with 80%. There were no significant differences in isolation frequency of I5SF by the collection time or populations of bark beetles. Sapwood discoloration underneath galleries was first observed around May 20, and then the degree of discoloration was increased up to 100% within two weeks. Among BSF isolated from adults, eggs/larvae, and galleries, Leptografthium species were more frequently isolated than Ophiostoma species.