1. Host plant density can affect insect herbivore oviposition behaviour, which can, in turn, affect both plant and herbivore populations. Because clear generalisations about density effects on oviposition remain elusive, a better understanding of underlying mechanisms is needed. One such mechanism is plantmediated effects (i.e. changes in plant traits with density), which are often suggested bu...

Plant sap-feeding insects and blood-feeding parasites are frequently depleted in (15)N relative to their diet. Unfortunately, most fluid-feeder/host nitrogen stable-isotope studies simply report stable-isotope signatures, but few attempt to elucidate the mechanism of isotopic trophic depletion. Here we address this deficit by investigating the nitrogen stable-isotope dynamics of a fluid-feeding...

What determines which plant species are susceptible to a given plant pathogen is poorly understood. Experimental inoculations with fungal pathogens of plant leaves in a tropical rain forest show that most fungal pathogens are polyphagous but that most plant species in a local community are resistant to any given pathogen. The likelihood that a pathogen can infect two plant species decreases con...

We propose a new mechanism based on sexual selection to explain the evolution of diet breadth in insects. More specifically, we show that mate choice in females for certain diet-derived male pheromones can be exploited by maternal effect genes that preferentially place offspring on a specific host plant, resulting in specialization. Our analytical model also suggests that the process is more li...

The present study was undertaken to verify ancient data in the literature on ovipositional preference o f the cuttlefish Sepia officinalis for the terrestrial plant Pistacia lentiscus (mastic tree). Adult specimens o f Sepia were placed in basins together with aerial parts not only of P. lentiscus, but also o f Artemisia arborescens, Centaurea alba var. deusta, Quercus ilex and Laurus nobilis. ...

The process of local adaptation creates diversity among allopatric populations, and may eventually lead to speciation. Plant-feeding insect populations that specialize on different host species provide an excellent opportunity to evaluate the causes of ecological specialization and the subsequent consequences for diversity. In this study, we used geographically separated Drosophila mettleri pop...

Human brugian filariasis, which is caused by Brugia malayi and B. timori , affects 13 million people in the oriental region (WHO 2002) and is most common in India and China (Ottesen et al. 1997). The most important vectors of B. malayi , in the endemic countries of South-east Asia, are different Mansonia species in the subgenus Mansonioides . The vectors of the parasite causing brugian filarias...

Bee-population declines are linked to nutritional shortages caused by land-use intensification, which reduces diversity and abundance of host-plant species. Bees require nectar and pollen floral resources that provide necessary carbohydrates, proteins, lipids, and micronutrients for survival, reproduction, and resilience to stress. However, nectar and pollen nutritional quality varies widely am...

Plant defenses aimed at necrotrophic pathogens appear to be genetically complex. Despite the apparent lack of a specific recognition of such necrotrophs by products of major R genes, biochemical, molecular, and genetic studies, in particular using the model plant Arabidopsis, have uncovered numerous host components critical for the outcome of such interactions. Although the JA signaling pathway...