Population Structure of Phytophagous Lepidoptera
Population Structure of Phytophagous Lepidoptera and Their Parasitoids: Relatedness, Patterns of Parasitoid Distribution, and Host-Parasitoid Interactions.
The genetic structure within and between demes represents the distribution of genetic variance at sequential hierarchical scales. That variance and its distribution clearly is influenced by numerous factors but among the most important factors, particularly within the context of assemblages, populations, or communities are the dispersal of species and associated levels of gene flow. Genetic variance and its distribution within and between demes (subpopulations) is critical to maintaining genetic diversity; upon which selection acts. The genetic structure within and between subpopulations establishes the distribution and to some extent the abundance of similar and dissimilar, behaviorally and ecologically interacting individuals. If the variance in the outcome of host-parasitoid interactions is in large part a function of the spatial distribution of genotypes that vary in their susceptibility to parasitoids then the genetic structure of host demes and populations (i.e., inter- and intra-demic genetic structure) is essential for the understanding of host-parasitoid dynamics. Thus, we propose to undertake a hierarchical, genetic characterization using molecular markers of individuals in populations, in which the smallest sampling unit will be parasitoids and macrolepidopteran larvae (collected from individual trees of several species, across several sites). We will determine the degree and scale of relatedness which ultimately is a reflection of patterns of progeny distribution of individual females of herbivore hosts and their parasitoids. Thus, we will be able to address questions such as, Are there distinct subpopulations (i.e., demes) of herbivore host species and their braconid parasitoids? If not, is there significant intrademic genetic variation across sites? That is, Are the distributions of the progeny of herbivores and that of parasitoids clumped or random, and at what scale? Does the pattern of distribution of the progeny of herbivore species represent a bet hedging strategy which minimizes vulnerability to parasitoids? If there are distinct demes, What are the differences in inter and intra demic genetic structure of herbivore species and their parasitoids? Are differences in inter- and intra-demic genetic structure associated with differences in gene flow and dispersal capacity of herbivores and parasitoids?
Participants: P. Barbosa/D. Hawthorne/A. Caldas
The genetic structure within and between demes represents the distribution of genetic variance at sequential hierarchical scales. That variance and its distribution clearly is influenced by numerous factors but among the most important factors, particularly within the context of assemblages, populations, or communities are the dispersal of species and associated levels of gene flow. Genetic variance and its distribution within and between demes (subpopulations) is critical to maintaining genetic diversity; upon which selection acts. The genetic structure within and between subpopulations establishes the distribution and to some extent the abundance of similar and dissimilar, behaviorally and ecologically interacting individuals. If the variance in the outcome of host-parasitoid interactions is in large part a function of the spatial distribution of genotypes that vary in their susceptibility to parasitoids then the genetic structure of host demes and populations (i.e., inter- and intra-demic genetic structure) is essential for the understanding of host-parasitoid dynamics. Thus, we propose to undertake a hierarchical, genetic characterization using molecular markers of individuals in populations, in which the smallest sampling unit will be parasitoids and macrolepidopteran larvae (collected from individual trees of several species, across several sites). We will determine the degree and scale of relatedness which ultimately is a reflection of patterns of progeny distribution of individual females of herbivore hosts and their parasitoids. Thus, we will be able to address questions such as, Are there distinct subpopulations (i.e., demes) of herbivore host species and their braconid parasitoids? If not, is there significant intrademic genetic variation across sites? That is, Are the distributions of the progeny of herbivores and that of parasitoids clumped or random, and at what scale? Does the pattern of distribution of the progeny of herbivore species represent a bet hedging strategy which minimizes vulnerability to parasitoids? If there are distinct demes, What are the differences in inter and intra demic genetic structure of herbivore species and their parasitoids? Are differences in inter- and intra-demic genetic structure associated with differences in gene flow and dispersal capacity of herbivores and parasitoids?
Participants: P. Barbosa/D. Hawthorne/A. Caldas