Global warming is widely predicted to reduce the biomass production of top predators, or even result in species loss. Several exceptions to this expectation have been identified, however, and it is vital that we understand the underlying mechanisms if we are to improve our ability to predict future trends. Here, we used a natural warming experiment in Iceland and quantitative theoretical predic...

Freshwater food webs are dominated by aquatic invertebrates whose trophic relationships are often poorly known. Here, I used laboratory experiments to study the role of a water bug, Sigara striata, as a potential predator and prey in food webs of stagnant waters. Multiple-choice predation experiment revealed that Sigara, which had been considered mostly herbivorous, also consumed larvae of Chir...

Visual signals are often under conflicting selection to be hidden from predators while being conspicuous to mates and rivals. Here, we investigated whether 3 different island populations of Aegean wall lizards (Podarcis erhardii) with variable coloration among diverse island habitats exhibit simultaneous camouflage and sexual signals. We examined whether signals appear better tuned to conspecif...

Generalist predators in terrestrial arthropod communities have traditionally been viewed as predators whose dynamics are less tightly coupled to any particular prey species, but whose ecological roles are in other respects analogous to those of specialist predators. Biological-control theory for predator–prey interactions has been based upon a model of communities composed of three discrete tro...

The mere presence of predators often decreases the growth rate of prey individuals, which devote energy and time to predator avoidance mechanisms. However, if time constraints are present, the prey individuals might be forced to neglect predators in order to grow faster. Amphibian larvae lower their activity when exposed to predators, which increases their survival probability but lowers their ...

There has been little research conducted on the effects of native or established predators on populations of the hemlock woolly adelgid, Adelges tsugae Annand, or the balsam woolly adelid, A. piceae Ratz. This paper reviews what is known about the native and established predators of both species in the southeast. Field surveys and cage exclusion experiments were used to examine the relationship...

Coexistence of predators that share the same prey is common. This is still the case in size-structured predator communities where predators consume prey species of different sizes (interspecific prey responses) or consume different size classes of the same species of prey (intraspecific prey responses). A mechanism has recently been proposed to explain coexistence between predators that differ ...

the european corn borer, ostrinia nubilalis (hübner), is an important insect pest of corn, zea mays l., crop in moghan region. in field experiments, the density of eggs and larvae of o.nubilalis and percentage of eggs and larvae parasitisms were studied on four corn hybrids ns704 (commercial cultivar), ns770, ns640 and mv524 (cultivars with high yield). furthermore, in this study, the predators...