|| 要旨トップ | 本企画の概要 |||日本生態学会第57回全国大会 (2010年3月，東京) 講演要旨|
Pre-dispersal seed predatory insects on dipterocarps need seeds to reproduce and increase their population size. Thus, they are animals being most affected by unstable seed production of dipterocarps. How insect predators response to mast fruiting and affect reproduction of diperocarps?
By intensive sampling throughout seed development, 3799 individuals of seed predatory insects were collected from 26910 fruits of 11 Shorea spp. in two mast fruiting events in Peninsular Malaysia. Insect species composition were similar in most of the Shorea species, while it was different from that of Dipterocarpus spp.
While Shorea spp. came into flower sequentially for ca. 3 months in each flowering event, emerging adults are unlikely to utilize the seeds in the same event. This implies that population build-up is unlikely to occur within an event.
Comparing between two flowering events occurring after 65 and 7 months from the preceding events, the population size of seed predators was larger in the latter event than the former event. Consequently, the trees fruiting in the latter event suffered higher seed predation.
These results suggest that synchronous mast fruiting by Shorea spp. with long intervals is effective to satiate insect predators and reduce their pre-dispersal seed predation rates, supporting ‘seed predator satiation’.