| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2004: ¥2,800,000 (Direct Cost: ¥2,800,000)
|
|---|
| Research Abstract |
Various population dynamic patterns generate in prey-predator experimental systems. In typical three-species experimental systems, we investigated 1 host-2 parasitoid system and 2 host-1 parasitoid one. A pteromalid wasp, Anisopteromalus calandrae, is a key-stone species in those systems. It makes the three-species experimental systems long-term persistence, because it controlled a braconid wasp, Heterospilus prosopidis, which had higher attack rate in the former system, and it attacked more a dominant competitor, Callosobruchus maculatus, in the latter system. We studied learning, behavior of A.calandrae for parasitism preference. In addition, population dynamics of the three species, time-series analysis and individual-based modeling.
Comparison between competition curves of the two bruchid species
C.chinensis and C.maculates were provided with Vigna angularis and V.sinensis seeds, and we compared the competition curves between the two bruchid species. C.maculates is a contest-type, do
… More
minant competitor, and it depressed competitively C.chinensis which is scramble.
Parasitoid's preference experiment
We provided A.calandrae with C.chinensis and C.maculates 4^<th>-instar larvae and pupae and measured the preference for the two bruchid host species. We made each emergent wasp attack ether con- or hetero-specific bruchid hosts in which the parasitoid grew, and we tracked paths of the wasp with video recording. These video-tracking and parasitism experiment allowed us learning behavior of A.calandrae. Preference of parasitism was reinforced more and more, depending on the parasitism numbers on each host and the number of days.
Observation of long-term three-species population dynamics
Long-term population dynamics was observed in three-species experimental systems. In the two-seed system, population cycles of dominant host species generated alternately and long-term persistence was seen in the three-species system. The same patterns were showed in a population dynamic model with switching and learning in parasitism. Less
|
