Theory predicts the bottom–up coupling of resource and consumer densities, and epidemiological models make the same prediction for host–parasite interactions. Empirical evidence that spatial variation in local host density drives parasite population density remains scarce, however. We test the coupling of consumer (parasite) and resource (host) populations using data from 310 populations of met...

the influence of parasitoids on population dynamics is affected by host instar preference. the preference pattern of host instars is not fixed and is modified by the availability and relative abundance of host instars, intensity of defensive behaviors in a particular instar, and also maternal effects of the female forager. in this study, host instar preference of the thelytokous strain of lysip...

Egg dispersion and the sex ratio of progeny were studied in relation to the host density of the parasitoid, Bracon hebetor Say, infesting larvae of Plodia interpunctella (H . ubner). Females appeared to allocate eggs in relation to host density to avoid laying more eggs than could complete development on a host. The dispersion pattern of the parasitoid ovipositions among hosts was influenced by...

Host population density is positively associated with the strength of social interactions or the frequency of physical contacts, and thus potentially influences microbial transmission among individuals. However, the relationship between host density and gut microbiota remains unknown. Here, we characterized the gut microbiota of plateau pikas (Ochotona curzoniae) in wild experimental fields wit...

Host density can increase infection rates and reduce host fitness as increasing population density enhances the risk of becoming infected either through increased encounter rate or because host condition may decline. Conceivably, potential hosts could take high host density as a cue to up-regulate their defence systems. However, as host density usually covaries with food availability, it is dif...

Models of parasitoid-host dynamics are analyzed that include direct density dependence in the host population and either parasitoid- or host-density-dependent variation in parasitoid recruitment per parasitized host (parasitoid "yield"). The principal question addressed is how these forms of density dependence in parasitoid dynamics combine with aggregated parasitism to affect the stability of ...

introduction: lysiphlebus fabarum marshall (hymenoptera: braconidae: aphidiinae) is a common aphidiine parasitoid in central europe, where it attacks more than 70 species of aphids. although both unisexual (thelytokous) and bisexual (arrhenotokous) strains of l. fabarum have been reported in iran, the former appear to be more widely distributed. aphid control in iran relies heavily on pesticide...

Parasites have been shown to reduce host density and to induce host population extinction in some cases but not in others. Epidemiological models suggest that variable effects of parasites on individual hosts can explain this variability on the population level. Here, we aim to support this hypothesis with a specific epidemiological model using a cross-parasite species approach. We compared the...

Considerations on the IPv6 Host Density Metric Status of This Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Abstract This memo provides an analysis of the Host Density metric as it is currently used to guide registry allocations of IPv6 unicast address blocks. This document contrasts ...