マツ生立木に対するマツノマダラカミキリ成虫の後食の影響 : (2) 大気環境条件の異なる若齢アカマツ自然林について

Effect of feeding by Monochumus alternatus on pine tree vitality : (2) A case of natural young Japanese red pine stands under different air pollution levels

岡馬 裕人

中根 周歩

富井 利安

戎 晃司

広島大学総合科学部紀要. IV, 理系編

Memoirs of the Faculty of Integrated Arts and Sciences, Hiroshima University. IV, Science reports

Six and nine individuals of the vector (Moncochamus alternatus) of pinewood nematode Bursaphelenchus xylophilus were placed into their own respective frames, which were covered with sheets of white nylon netting in order to prevent escape, for one month (June 24 to July 23,1998) at both natural young Japanese red pine (Pinus densiflora) stands located at Hachihonmatsu in Higashi-Hiroshima and Fukutomi-cho in Hiroshima Pref., where the air pollution levels were different from each other. The feeding effect of the vectors on was then traced in the field during 10 months (June 1998 to March 1999). Sixty-four of 67 trees in the four frames at the both stands, into which six or nine vectors were placed, were fed on by the vectors. However, only one of these 64 died in the frame of nine vectors at Hachihonmatsu site under heavy air pollution, even though the vectors has about 4,000 nemotode on average. No nematode could be found out in the most hardly fed pine tree in each frame, including dead pine tree. This suggests that the damage killing young pine trees is not caused by the feeding of vectors even in a population density of 6-9 individuals/25m^2 employed in the study, which may be extremely higher than that in the field.

Bursaphelenchus xylophilus

Feeding

Monochamus alternatus

Natural pine stand

Pinus densiflora

Tree vitality

林業 [ 650 ]

日本語

広島大学総合科学部

[作成日] 2006-03-21

[ISSN] 1340-8364

[NCID] AN10435936