Solomon Bruce Peary, McNaughton S J
Department of Biology, Syracuse University, 13210, Syracuse, N.Y., USA.
Oecologia. 1979 Jan;42(1):47-56. doi: 10.1007/BF00347617.
Densities were examined in natural populations consisting of horsenettle (Solanum carolinense), larvae of a horsenettle-specific phytophagous moth (Frumenta nundinella), and a polyphagous parasitoid wasp (Scambus pterophori), that parasitized the moth. Herbivore and parasitoid densities were both positively associated with fruit density, but moth larval density was linear while parasitoid density increased parabolically; thus, optimum moth survivorship was at intermediate moth densities. There was no evidence of escape from herbivory in time by plant populations due to either mean flowering date or a spread of flowering in seasonal time. However, one plant population and one moth population apparently escaped in space due to isolated location. Although plant reproductive success is reduced whether or not moth larvae are parasitized, both presence of a numerical herbivore refuge and parasitoid attack at high fruit and moth densities would be expected to stabilize long-term temporal dynamics of this simple food chain.
在由刺萼龙葵（Solanum carolinense）、一种专食刺萼龙葵的植食性蛾（Frumenta nundinella）的幼虫以及寄生于该蛾的多食性寄生蜂（Scambus pterophori）组成的自然种群中，对密度进行了研究。食草动物和寄生蜂的密度均与果实密度呈正相关，但蛾幼虫密度呈线性关系，而寄生蜂密度呈抛物线形增加；因此，蛾的最佳存活率处于中等蛾密度水平。没有证据表明植物种群因平均开花日期或季节性开花时间的扩散而及时逃避食草作用。然而，由于地理位置孤立，一个植物种群和一个蛾种群显然在空间上逃避了。尽管无论蛾幼虫是否被寄生，植物的繁殖成功率都会降低，但预计在高果实和蛾密度下，数量上的食草动物避难所的存在以及寄生蜂的攻击都将稳定这条简单食物链的长期时间动态。
