Nesting density and synchrony by hosts may indirectly serve as a defense mechanism against brood parasites. Here we examine the relationships between spatial and temporal distribution of host nests and the probability of being parasitized. We use as host species the Black-billed Magpie (Pica pica), a species that is parasitized by the Great Spotted Cuckoo (Clamator glandark) in southern Europe....

Ecological and evolutionary theories predict that parasitism and mutualism are not fixed endpoints of the symbiotic spectrum. Rather, parasitism and mutualism may be host or environment dependent, induced by the same genetic machinery, and shifted due to selection. These models presume the existence of genetic or environmental variation that can spur incipient changes in symbiotic lifestyle. Ho...

effect of water gas shift reaction (co+h2o=co2+h2) on wustite reduction has been investigated by a transient, non-isothermal mathematical model based on grain model. in this model, wustite porous pellet is reduced using syngas, namely a mixture of hydrogen, carbon monoxide, carbon dioxide and water vapor. for this purpose, governing equations containing continuity equation of species and energy...

Sexual selection can improve population fitness and purge deleterious mutation from the gene pool by promoting condition-dependent mate selection. One ecological factor that reduces individual condition is parasitism. Parasitism tends to increase hosts' load likely indicates inferior host genetic quality. Parasite-mediated selection, therefore, should favour mating success of parasite-resistant...

Homalodisca coagulata (Say) (Hemiptera: Cicadellidae) eggs 1–10 days of age were exposed to Gonatocerus ashmeadi Girault, Gonatocerus triguttatus Girault, and Gonatocerus fasciatus Girault (all Hymenoptera: Mymaridae) in no choice laboratory trials to investigate egg age utilization and to determine which egg ages are vulnerable to attack by these three parasitoids. The H. coagulata egg ages th...

Honey bee (Apis mellifera) gene expression related to immunity for hymenoptaecin (AmHym) and defensin-1 (AmDef-1), longevity for vitellogenin (AmVit2) and stem cell proliferation for poly U binding factor 68 kDa (AmPuf68) was compared following Varroa destructor parasitism, buffer injection and injection of V. destructor compounds in its homogenate. In adults, V. destructor parasitism decreased...

Field parasitism rates of the Argentine stem weevil Listronotus bonariensis (Kuschel; Coleoptera: Curculionidae) by Microctonus hyperodae Loan (Hymenoptera: Braconidae) are known to vary according to different host Lolium species that also differ in ploidy. To further investigate this, a laboratory study was conducted to examine parasitism rates on tetraploid Italian Lolium multiflorum, diploid...