Only inoculum containing nematodes, pure suspension of Bursaphelenchus sp. However, conidia of Pestalotia and filtrate from the mixed suspension proved to be harmless to healthy pine trees. As inoculum suspension was prepared by washing the Bursaphelenchus-Pestalotia culture, it contained nematodes and conidia of the fungus. (2) Nematodes used as inoculum were multiplied on the colony of Pestalotia sp. Therefore, pine trees were usually inoculated with 30, 000 nematodes per tree in the other inoculation series. (1) When about 600 nematodes were injected into the heartwood at the base of stem, amounts of oleoresin exudation from the punched wound gradually reduced but the inoculated trees did not die after all whereas almost all of pine trees inoculated with the nematodes at the rate of more than 30, 000 per tree were finally killed (Table 2). Results obtained are summarized as follows: detected from the dead pine tree is considered as one of the causal agents for the death of pine trees and it plays an important role in the deterioration of pine forests throughout the southwestern part of Japan. From these experiments the authors came to the conclusions that Bursaphelenchus sp.
#THE FOREST SEIL HERSTELLEN SERIES#
To determine the effect of this nematode onto healthy pine tree, several series of inoculation test were conducted in certain pine stands (Table 1). In the previous paper (TOKUSHIGE & KIYOHARA 1)) the authors reported preliminarily that a species of nematode, Bursaphelenchus sp., was commonly detected in the wood of dead pine trees collected from many localities in Kyushu. The cause of this damage has been attributed to the attack of bark beetles up to the present time. A large number of pine trees in many stands declined and finally died off for instance, about 39-million trees or 380-thousand cubic metres in volume were damaged in 1968. Epidemic occurrence of a virulent blight of pine trees throughout the southwestern part of Japan, especially in Kyushu district, has long been noticed among Japanese foresters.