BACKGROUND Sympatric speciation-the divergence of populations into new species in absence of geographic barriers to hybridization-is the most debated mode of diversification of life forms. Parasitic organisms are prominent models for sympatric speciation, because they may colonise new hosts within the same geographic area and diverge through host specialization. However, it has been argued that...

There is a growing appreciation in general population and community ecology of the critical importance of space and spatial phenomena for understanding a wide range of ecological phenomena. At the scale of an invading pathogenic organism, a host organism in some important respects is like a large, complex landscape, on which the infection may play out in space as well as time. Many of the topic...

Seasonal samples of all fish species from Lake Moreno were taken in order to determine the presence of paratenia, to evaluate the status of the hosts and to characterise the transmission of Acanthocephalus tumescens (von Linstow, 1896) at the component population level. Prevalence, mean abundance, mean intensity, numbers of gravid females, relative abundance of the different fish species, relat...

Parasitic relationships between Neotropical bats and their ectoparasites are not well known, even though parasitism is one of the factors that can affect fitness a host population. This study characterized parasite-host in relation to sex, age, body size reproductive status population Anoura geoffroyi using indices Prevalence, Mean Intensity Abundance. Total prevalence for 93 sampled was 94.6%....

The population component of a species' niche corresponds to the distribution of individuals across environments within a region. As evolutionary clades of species diversify, they presumably fill niche space, and, consequently, the rate of increase in species numbers slows. Total niche space and species numbers appear to be relatively stable over long periods, and so an increase in the species r...

Evolutionary radiations have been well documented in plants and insects, and natural selection may often underly these radiations. If radiations are adaptive, the diversity of species could be due to ecological speciation in these lineages. Agromyzid flies exhibit patterns of repeated host-associated radiations. We investigated whether host-associated population divergence and evidence of diver...

Population and community descriptor values (parasites per host, prevalence per parasite species, variance/mean ratios, species density, and diversity indices) for the 7-species parasite community of 61 relatively homogeneous samples of Fundulus zebrinus (Pisces: Cyprinodontidae) in the South Platte River of Nebraska, U.S.A., taken over a 14-yr period, are reported. South Platte River streamflow...

A co-structure study is a comparison of demographic and/or genetic structure between two or more species. Such a comparative analysis among a parasite and its host(s) or among multiple parasite species is useful to elucidate factors that shape genetic variation within and among parasite populations. I provide a brief review of how co-structure studies in parasite systems can be used to address ...

In recent years, the pest status of Liriomyza trifolii (Burgess) and L. huidobrensis (Blanchard) (Diptera: Agromyzidae) has changed in California, as well as other areas of the world. In California, L. huidobrensis has become the predominant Liriomyza species in valleys along the central coast, while L. trifolii remains the predominant species in southern California. To investigate possible rea...

background: the species of ectoparasites that live on a specific host in a geographical region form an ectoparasite community. species abundance distributions describe the number of individuals observed for each different species that is encountered within a community. based on properties of the species abundance distribution, the expected total number of species present in the community can be...