Regulation of microbial population density is a necessity in stable symbiotic interactions. In Wolbachia symbiosis, both bacterial and host genotypes are involved in density regulation, but environmental factors may also affect bacterial population density. Here, we studied the interaction between three strains of Wolbachia in two divergent homozygous lines of the wasp Leptopilina heterotoma at...

Recent controversy over whether biodiversity reduces disease risk (dilution effect) has focused on the ecology of Lyme disease, a tick-borne zoonosis. A criticism of the dilution effect is that increasing host species richness might amplify disease risk, assuming that total host abundance, and therefore feeding opportunities for ticks, increase with species richness. In contrast, a dilution eff...

ABSTRACT The effect of plant density on disease is not well understood in populations of a single host plant genotype and has been studied even less in mixtures of host genotypes. We performed an experiment to evaluate the effect of wheat planting density on infection by Puccinia striiformis in experimental plots with a single wheat genotype and in plots with two genotypes making up a range of ...

Anaphes iole Girault is a solitary egg parasitoid which attacks Lygus spp. In a low-parasitoid-density experiment (parasitoid:host ratio 5 1:40) 10.0% of available Lygus hesperus Knight eggs were superparasitized by A. iole. However, in experiments with a high parasitoid density (parasitoid:host ratio 5 1:9), superparasitism of L. hesperus eggs was 33.3, 66.7, and 82.2% after exposure for 2, 6,...

background: biting habit of mosquitoes plays an important role in the epidemiology of mosquito-borne diseases. mosquitoes use a set of elaborate sensory modalities to find their preferred hosts by exploiting cues emanating from a nearby host. it has been suggested that the chemical profile of skin can provide further support for anthropophilic mosquito species to find their suitable hosts. this...

1. The dynamics of parasitic organisms depend critically upon the frequency distribution of parasite individuals per host. However, the processes giving rise to this frequency distribution have rarely been modelled and tested for organisms with complex host selection behaviour. 2. In this study Microrhopala vittata, a chrysomelid beetle, was used to investigate how oviposition behaviour, moveme...

introduction: varicocele is considered as a common cause of male infertility. the aim of this study was to evaluate the effects of varicocelectomy on sperm parameters, sperm membrane integrity and sperm nuclear maturity. materials and methods: in this study along with routine semen analysis, hypo-osmotic swelling test (host), and aniline blue staining for assessment of as 45 and 90 days after i...