Analysis of heterospecific society of Chrysolina aurichalcea species complex by using the methods of cytogenetics and population genetics.

1992 Fiscal Year Final Research Report Summary

• Project/Area Number: 03640551
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 生態学
• Research Institution: Shinshu University
• Principal Investigator: FUJIYAMA Shizuo Shinshu University, Department of Biology, Associate Professor, 理学部, 助教授 (70109164)
• Project Period (FY): 1991 – 1992
• Keywords: species complex / heterospecific society / hybrids / color dimorphism / mixed population / mating / behavior / diurnal activity

Research Abstract

The heterospecific societies of Chrysolina aurichalcea species complex were studied on the field experiments. The adults with two types of chromosome numbers were released on the field of Artemisia princeps by three different population densities(from 1 to 10 individuals/m^2) in the beginning of their reproductive season(Sept.). The field observations were made from then to November. The males mate often with the females of different chromosome numbers at the highest density(c.a.20-30%). While at the intermediate density, the frequency reduced to c.a.10%. And furthermore, at the lowest density, the males did not mate with the females with the different chromosome number but with the ones with the same chromosome number. Thus, the interspecific relation changed with not only the population density but also the physical environmental conditions e.g. the duration of sunshine and the existence of wood cover.