The predatory xanthid crabs Eurytjum limosurn and Panopeus herbstii are common components of benthic assemblages in different intertidal habitats within salt marshes around Sapelo Island. Georgia, USA. E. limosum feed primarily on other crabs and are found where cordgrass Spartina altemiflora stems are the dominant structural elements in the environment. P: herbstii feed largely on bivalve moll...

Amblyseius orientalis (Ehara) (Acari: Phytoseiidae) is a native predatory mite species in China. It used to be considered as a specialist predator of spider mites. However, recent studies show it also preys on other small arthropod pests, such as Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Experiments were conducted to investigate (1) prey preference of A. orientalis between Tetranychu...

The whiteflies Bemisia tabaci Gennadius and Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) are two of the main pests in tomato crops. Their biological control in Mediterranean IPM systems is based on the predators Macrolophus pygmaeus (Rambur) and Nesidiocoris tenuis Reuter (Hemiptera: Miridae), as well as on the parasitoids Eretmocerus mundus (Mercet) and Encarsia pergandiella H...

25 26 The functional response describes the relationship between feeding rate and prey density, and 27 is important ecologically as it describes how the foraging behaviour of an animal changes in 28 response to food availability. The effects of habitat complexity and food item size was 29 experimentally tested here on the foraging parameters and the functional responses of the 30 freshwater fis...

The energy balance approach helps to understand the limits within which ‘predator–prey’ relationship can form, but cannot explain formation of trophic links in natural multispecies systems. A time study feeding has been developed complement it. In hypersaline Lake Moynaki (Crimea) a simple food web, there is one omnivorous species, Gammarus aequicauda, and two abundant prey, planktonic Moina sa...

In this study, we test the classical prey model of optimal-foraging theory with great tits (Parus major) feeding on two types of mealworms presented on a conveyor belt. Contrary to the results of some previous experiments, prey types were given to birds in random order, therefore birds could not predict their next prey item. We tested birds’ diet choices at four different prey-encounter rates. ...

Foraging by mammals is a complex suite of behaviors that can entail high energetic costs associated with supporting basal metabolism, locomotion and the digestion of prey. To determine the contribution of these various costs in a free-ranging marine mammal, we measured the post-dive oxygen consumption of adult Weddell seals (N=9) performing foraging and non-foraging dives from an isolated ice h...

Predators may have multiple effects on prey, including the mortality caused by consumption, but also non-consumptive effects when prey alter their life history traits in the presence of predators. This study aimed to describe the consumption ability and the non-consumptive effects of Notonecta sellata (Heteroptera: Notonectidae) on immature stages of Culex pipiens (Diptera: Culicidae). Results ...

Consumption of emergent aquatic insects by terrestrial invertebrates is a poorly resolved, but potentially important, mechanism of contaminant flux across ecosystem borders leading to contaminant exposure in terrestrial invertivores. We characterized the spatial extent and magnitude of contaminant transfer from aquatic sediments to terrestrial invertebrate predators by examining riparian aranei...

A non-smooth Gause predator–prey model with a constant refuge is proposed and analyzed. Firstly, the existence and stability of regular, virtual, pseudo-equilibria and tangent points are addressed. Then the relations between the existence of a regular equilibrium and a pseudo-equilibrium are studied, and the results indicate that the two types of equilibria cannot coexist. The sufficient and ne...