Imperfect diet choice reduces the performance of a predatory mite.

Two mutually unexclusive hypotheses prevail in the theory of nutritional ecology: the balanced diet hypothesis states that consumers feed on different food items because they have complementary nutrient and energy compositions. The toxin-dilution hypothesis poses that consumers feed on different food items to dilute the toxins present in each. Both predict that consumers should not feed on low-quality food when ample high-quality food forming a complete diet is present.

Prey exploitation and dispersal strategies vary among natural populations of a predatory mite.

When predators commonly overexploit local prey populations, dispersal drives the dynamics in local patches, which together form a metapopulation. Two extremes in a continuum of dispersal strategies are distinguished: the "Killer" strategy, where predators only start dispersing when all prey are eliminated, and the "Milker" strategy, in which predator dispersal occurs irrespective of prey availability. Theory shows that the Milker strategy is not evolutionarily stable if local populations are well connected by dispersal.

Spatial patterns generated by simultaneous cooperation and exploitation favour the evolution of altruism.

In kin selection theory in the evolution of social behaviours, the relatedness between interacting individuals is influenced by the spatial structure of the population. It is generally considered that in the 'viscous' population competition among individuals tends to suppress the evolution of altruism. We consider that more complex interactions produce specific spatial patterns in the presence of competitive interaction, which could alter the process of kin selection in a given space.

Predatory interactions between prey affect patch selection by predators.

Abstract: When predators can use several prey species as food sources, they are known to select prey according to foraging efficiency and food quality. However, interactions between the prey species may also affect prey choice, and this has received limited attention. The effect of one such interaction, intraguild predation between prey, on patch selection by predators was studied here.

Predator performance is impaired by the presence of a second prey species.

The simultaneous infestation of a plant by several species of herbivores may affect the attractiveness of plants to the natural enemies of one of the herbivores. We studied the effect of coconut fruits infested by the pests Aceria guerreronis and Steneotarsonemus concavuscutum, which are generally found together under the coconut perianth. The predatory mite Neoseiulus baraki produced lower numbers of offspring on fruits infested with S.