1. Most trophic interaction theory assumes that all predators are an abstract form of risk to which prey respond in a quantitatively similar manner. This conceptualization can be problematic because recent empirical work demonstrates that variation in the responses of prey to different predators can play a key role in structuring communities and regulating ecosystem function. 2. Predator identi...

Symbiotic trade-offs dominate the world of biology and medicine in colonist-host relationships and between separate, mutually dependent organisms of different species. Infectious and parasitic diseases can be better understood by exploring the dynamic continuum between pathogenicity and mutualism, between antagonism and cooperation-the sliding scale along which microorganisms can move in a mome...

1. Animals usually require information about the current state of their habitat to optimize their behaviour. For this, they can use a learning process through which their estimate is continually updated according to the cues they perceive. Identifying these cues is a long-standing but still inveterate challenge for ecologists. 2. The use of plant cues by aphid parasitoids for the assessment of ...

1. Optimal foraging models ultimately predict that female parasitoids should exploit rich host patches for longer than poorer ones. At the proximate level, mechanistic models and experimental studies show that parasitoids use both chemicals produced by their hosts and direct encounters with their hosts to estimate patch quality. Although it has been extensively studied in the context of host lo...

Among the pests of cassava, the shoot fly, Neosilba perezi (Romero & Ruppell), is one of the most prevalent. It attacks mainly the terminal shoots and causes infested plants to produce lateral shoots. Reports on this species are rare or inexistent; thus, the purpose of this study was to assess three different areas for N. perezi infestation. The survey began in March 2008 and finished in Februa...

Strigolactones are a class of carotenoid-derived plant hormones, which impact many functions metabolism in response to environmental stress. They also act as exogenous signals perceived by both mycorrhizal fungi and parasitic plants. The peculiar chemical skeleton these molecules their mode action plants inspired possible applications biomedical fields. In this minireview, an overview the most ...

Arbuscular mycorrhizal (AM) fungi are important plant mutualists that can connect roots of neighboring plants to form common mycelial networks. A recent study demonstrated that these networks can act as conduits for aphid-induced signals between plants, activating chemical defenses in uninfested neighboring plants so that they become unattractive to aphids but attractive to their enemies (paras...

Soils with specific suppressiveness to plant-parasitic nematodes are of interest to define the mechanisms that regulate population density. Suppressive soils prevent nematodes from establishing and from causing disease, and they diminish disease severity after initial nematode damage in continuous culturing of a host. A range of non-specific and specific soil treatments, followed by infestation...

Floristic analyses do not support the hypothesis that the fynbos biome is more susceptible to alien plant invasions than are other South African biomes. Current levels of infestation, as indicated by vegetation surveys, indicate that the fynbos is more severely invaded than the other biomes. Hypotheses that have been proposed to explain the invasion of the fynbos by alien plants are listed. Vir...