1987 Fiscal Year Final Research Report Summary
Communication of the minute pine bark beetle, Cryphalus fulvus Niijima (Coleoptera: Scolytidae).
| Project/Area Number |
61560059
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物保護
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| Research Institution | Kyoto Prefectural University |
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Principal Investigator |
SASAKAWA Mitsuhiro Professor, Faculty of Agriculture, Kyoto Prefectural University., 農学部, 教授 (20046410)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIYASU Yutaka Assistant, Faculty of Agriculture, Kyoto Prefectural University., 農学部, 助手 (90038315)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Minute Pine Bark Beetle / flight behavior / communication / stridulation |
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| Research Abstract |
Cryphalus fulvus is one of the most destractive species of the Japanese red-pine, Pinus densiflora Sieb. et Zucc. It passes through three generations per year in Kyoto. Pioneer females fly at a height of about 4 m above ground-level in and out of stand, and land at random on healthy and weakened pine trees during the period of pre-aggregation flight. Dispersal flight peak occurs between 25-34゜C, and flight behavior is more extremely affected by the illumination than the pheromone in the distance. Once she bores in a weakened tree without resin pressure, mass attack is initiated by teh both sexes on that tree, owing to her production of aggregation pheromone. It seemed that response of beetles for pheromone is restricted within about 50 cm from the source.
Female in the egg gallery recognizes his arrival through the male elytra-abdominal tergite stridulation which is consisted of about nineteen pulse at intervals of about 64 ms. While the vertex-pronotal stridulation of male is an intermittent chirp at intervals of about 200 ms, when he pushes the female in the gallery or is aggressive against the other male.
A parasitoid, Ecphylus hattorii kono et Watanabe (Braconidae) lays usually eggs on the second instar larvae of the minute pine bark beetle. She walks around on the bark of pine, drumming with antennae. Her walking time was markedly shortened and she stopped more frequently on the host-boring log as compared with the control log. If she was able to search for the host larvae under bark through the larval feeding sound, she commenced a turning movement on that point and immediately insert her ovipositor into bark. Hot-spot produced by the larva is not a cue for host finding of this species.
Chemo-acoustic interaction, therefore, plays a role in the colonization behavior of this species.
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