Parasites may be expected to become locally adapted to their hosts. However, while many empirical studies have demonstrated local parasite adaptation, others have failed to demonstrate it, or have shown local parasite maladaptation. Researchers have suggested that gene flow can swamp local parasite-host dynamics and produce local adaptation only at certain geographical scales; others have argue...

Most veterinarians continue to recommend anthelmintic (dewormer) treatment programs for horses that are based on knowledge and concepts that are more than 40 years old. However, recent studies demonstrate that resistance and multiple-drug resistance in equine parasites is extremely common, but few horse owners or veterinarians take this into account when making treatment decisions. Parasites ar...

A nearly ubiquitous feature of plant-pathogen interactions is host cell death. In its most recognizable form, host cell death is manifested as the rapid collapse of tissue, termed the hypersensitive response (HR). This response accompanies “incompatible interactions” and leads to disease resistance. As detailed below, the HR is programmed genetically in the plant and is a consequence of new hos...

Host resistance to parasites can come in two main forms: hosts may either reduce the probability of parasite infection (anti-infection resistance) or reduce parasite growth after infection has occurred (anti-growth resistance). Both resistance mechanisms are often imperfect, meaning that they do not fully prevent or clear infections. Theoretical work has suggested that imperfect anti-growth res...

The choice of effective empirical treatment of fever in the neutropenic host requires a sound knowledge of the local microbial epidemiology and the susceptibility patterns of pathogens. Since the list of possible pathogens can, at best, only be narrowed to a few most likely organisms, the use of empirical broad-spectrum antibiotic therapy in such situations is warranted. Indeed, the empirical u...

Background: The antagonistic co-evolution of hosts and their parasites is considered to be a potential driving force in maintaining host genetic variation including sexual reproduction and recombination. The examination of this hypothesis calls for information about the genetic basis of host-parasite interactions – such as how many genes are involved, how big an effect these genes have and whet...

the relationship between female oviposition preference and offspring performance is a key area of study on the evolution of host specificity. this study investigates host prefer-ence of the polyphagous hover fly syrphus ribesii (diptera: syrphidae) and compares it with some components of its offspring`s performance. females and offspring were tested on six naturally used aphid hosts (blackberry...

Supplementary Methods Modeling methods: We used a mathematical model to describe how the timescale and predictability of temperature variation should interact to influence the geometric population growth rate (G) of a microparasite within a host, assuming the same level of parasite exposure for all hosts. In this model, we explored the consequences of differential rates of parasite and host acc...