| Co-Investigator(Kenkyū-buntansha) |
KAJIMURA Hisashi School of Bioagricultural Sciences, Nagoya University, Assistant Professor, 生命農学研究科, 助手 (10283425)
HIJII Naoki School of Bioagricultural Sciences, Nagoya University, Associate Professor, 生命農学研究科, 助教授 (80202274)
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| Research Abstract |
Numerous plant-eating insects inhabit forests, feeding on leaves, bark, wood, roots, seeds and other plant parts. Among them, the bark- and wood-boring insects utilize mostly inner bark (phloem), cambium, and wood (xylem) as their food resources. In general, most woody tissues are nutritionally poorer than leaf tissue when considered as a substratum for insect g rowth and development. Hence, to compensate for such poor nutrient conditions, some species of woodwasps (Siricidae) introduced Amylostereum fungi into trees during oviposition, which then decays the wood and provide nutrients to the developing larvae, and still other insects such as ambrosia beetles (Scolytidae), which inhabit wood, had also come to depend solely on fungus as their source of food. Because bark- and wood-boring larvae are unable to exit the woody tissues of their host trees during development, their eventual adult body size often varies considerably more than free-living insects due to high nutritional heterogeneity in the woody habitat. In many coniferous trees, it is known that resin is an important factor for defense against bark beetles and wood-borers that attack living trees. Thus, development and survival of bark- and wood-boring insects appeared to be closely affected by host tree conditions such as nutrient levels and resin flow.
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