one may find out the application‎ ‎of mathematics in the areas of ecology‎, ‎biology‎, ‎environmental‎ ‎sciences etc‎. ‎mathematics is particulary used in the problem of‎ ‎predator-prey known as lotka-volterra predator-prey equations.‎ ‎indeed‎, ‎differential equations is employed very much in many areas‎ ‎of other sciences‎. ‎however‎, ‎most of natural problems involve some‎ ‎unknown functions...

the food chain refers to a natural system by which energy is transmitted from one organism to another. in fact, a food chain consists of producers, consumers and decomposition. presence of complex food web increase the stability of the ecosystem. classical food chain theory arises from lotka-volterra model. in the present paper, the dynamics behavior of three level food chain is studied. a syst...

life table gives the most comprehensive explanation of the survivorship, development, and reproduction of a population. the life table parameters of an aphidophagous midge, aphidoletes aphidimyza were studied on different densities (5, 10, 20, 40, 60, 80) of third instar nymphs of aphis gossypii as prey in a growth chamber (25 ± 1 °c, 70 ± 5% rh and a photoperiod of 16l: 8d h). the pre-oviposit...

predation rate is basic to any investigation of prey-predator interaction and a major component in the selection of predators for biological control. the predation rate of variegated lady beetle, hippodamia variegata (goze), fed on different densities (20, 40, 60, 80 and 100) of third instar nymphs of cotton aphid, aphis gossypii glover, was studied under laboratory conditions (25 ± 1 °c, 65 ± ...

the predator-prey model with stage structure for predator is generalized in the context of ecoepidemiology, where the prey population is infected by a microparasite and the predator completely avoids consuming the infected prey. the intraspecific competition of infected prey is considered. all the equilibria are characterized and the existence of a hopf bifurcation at the coexistence equilibriu...

The rodents’ fauna of boundary zones of Iran are still poorly known. In this research rodents fauna of Khaf township in northeast of Iran have been reported mainly based on pellets of birds of prey. Alive samples and also rodent’s remains from pellet materials of birds of prey in the present study was collected from 46 localities in Khaf, northeast of KhorasanRazavi province and different speci...

intraguild predation (igp) occurs when one predator species consumes another predator species with whom it also competes for shared prey. we studied igp between different stages of hippodamia variegata and aphidoletes aphidimyza in absence and presence of extraguild prey (aphis gossypii) in petri dish arena. in the absence of extraguild prey all stages of h. variegata (larva1, 2, 3, 4, female a...

Diet of adult pikeperch Sander lucioperca, Eurasian perch Perca fluviatilis, northern pike Esox lucius and European catfish Silurus glanis as top predators in aquatic ecosystems in Serbia was investigated during 2011, in order to understand their relationship to their prey and to investigate their food consumption, feeding and assimilation rate, cannibalism, and habitat segregation. Northern pi...