Effect of Contest and Scramble Competition on Population Dynamics.

1. 以竞争型和争夺型两种野鲷为研究对象，对其幼虫的攻击行为进行了研究。三、四龄幼虫对同种和异种幼虫均表现出强烈的攻击行为。在所有阶段均未观察到这种攻击行为。以绿豆（Vigna radiata）为资源，进行了沙蚕与phaseoli的多代种间竞争实验。对于大尺寸的豆子，C. analis在200天内就从系统中消失了。对于小尺寸的豆子，在200天内就可以消灭phaseoli。两种大小的豆子等量混合，两种物种共存超过460天。这些结果完全可以用1.3中行为观察的结果来解释。采用竞争型策略和争夺型策略，研究了两种品种的斑斑鱼攻击行为的遗传机制。结果表明，相关基因为加性多基因。对这两种菌株的幼虫攻击行为进行了研究。竞争型菌株在整个幼虫期都表现出攻击行为。争夺型菌株仅在幼虫后期表现出攻击行为。这些结果与1.5中所观察到的C. analis和C. phaseoli有很大的不同。我进行了两株C. maculatus的多代种内竞争实验，类似于2。在种群规模上，趋近于小豆争夺型，趋近于小豆争夺型。通过混合豆子，系统显示了两种战略家类型的共存。通过回交分析系统中个体的遗传结构，发现大豆类系统已趋同为争抢型。而在小豆和混合豆的组合中，个体的遗传结构与争夺型和竞争型的F_1个体相同。少

1. Using the two bruchid species, a contest type strategist (Callosobruchus analis), and a scramble type strategist (C. phaseoli), I investigated the aggressive behavior of their larvae. The third and fourth instar larvae of C. analis showed the strong aggressive behavior against conspecific and heterospecific larvae alike. No such aggressive behavior was observed at any larval stages of C. phaseoli.2. I performed multi-generation interspecific competition experiment between C. analis and C. phaseoli, using mung bean (Vigna radiata) as their resource. With large sized beans, C. analis was eliminated from the system within 200 days. With small sized beans, C. phaseoli was eliminated within 200 days. With mixture of equal amount of beans of the two sizes, the two species coexisted for more than 460 days. These results were fully explainable from the results of behavioral observations conducted in 1.3. Using the two strains of C. maculatus, one with contest type strategy and the other wit … More h scramble type strategy, I investigated the genetic mechanism of aggressive behavior. The genes responsible was shown to be additive multiple genes.4. I investigated the larval aggressive behavior of the above two strains. The contest type strain showed the aggressive behavior all through their larval stages. The scramble type strain showed the aggressive behavior only in their late larva stage. These results are quite different from those of C. analis and C. phaseoli observed in 1.5. I conducted multi-generation intraspecific competition experiment between the two strains of C. maculatus, similar to that done in 2. In terms of population size, the system converged to scramble type with small beans, and it converged to contest type with small beans. With mixed beans, the system showed the coexistence of the two strategist types. When the genetic structure of the individuals in the system was analyzed by backcrossing them to those of stock cultures, the system with large beans was shown to have converged to scramble type. However, with small beans and with mixed beans, the individuals in the systems showed the same genetic structure as those seen in F_1 individuals between scramble and contest types. Less