نتایج جستجو برای: parasitic egg
تعداد نتایج: 75797 فیلتر نتایج به سال:
In many taxa, females lay eggs in the nests of other conspecifics. To determine the conditions under which conspecific brood parasitism develops, it is necessary to identify parasitic offspring and the females who produce them; however, for most systems parasitism can be difficult to observe and most genetic approaches have relatively low resolving power. In this study, we used protein fingerpr...
Hosts of brood-parasitic birds must distinguish their own eggs from parasitic mimics, or pay the cost of mistakenly raising a foreign chick. Egg discrimination is easier when different host females of the same species each lay visually distinctive eggs (egg 'signatures'), which helps to foil mimicry by parasites. Here, we ask whether brood parasitism is associated with lower levels of correlati...
Introdution: Chemical drugs against parasites are beneficial, but this method has some problems such as drug resistance, residue and unwanted side effects associated. Therefore, study on alternative therapies especially herbal compounds are research priorities. According to antimicrobial and anti-parasitic effects of Artemisia spp. extracts, this work aimed to study the effect of Artemisia spec...
How to evade a coevolving brood parasite: egg discrimination versus egg variability as host defences
Arms races between avian brood parasites and their hosts often result in parasitic mimicry of host eggs, to evade rejection. Once egg mimicry has evolved, host defences could escalate in two ways: (i) hosts could improve their level of egg discrimination; and (ii) negative frequency-dependent selection could generate increased variation in egg appearance (polymorphism) among individuals. Profic...
Many brood parasitic birds lay eggs that mimic their hosts' eggs in appearance. This typically arises from selection from discriminating hosts that reject eggs which differ from their own. However, selection on parasitic eggs may also arise from parasites themselves, because it should pay a laying parasitic female to detect and destroy another parasitic egg previously laid in the same host nest...
Parasites that exploit multiple hosts often experience diversifying selection for host-specific adaptations. This can result in multiple strains of host specialists coexisting within a single parasitic species. A long-standing conundrum is how such sympatric host races can be maintained within a single parasitic species in the face of interbreeding among conspecifics specializing on different h...
The effects of soil management systems on root-knot nematode (Meloidogyne incognita) eggs and gall incidence on tomato (Lycopersicon esculentum) and cucumber (Cucumis sativus) following tomato were evaluated. Soil was collected from a replicated field experiment in which six management systems were being assessed for vegetable production. Soil management systems were conventional production, or...
Parasitic dinoflagellates have recently emerged as significant disease agents of commercially important crustaceans. For example, epizootics of Hematodinium have seriously affected certain crab and lobster fisheries. The parasitic dinoflagellates of crustaceans are, however, relatively unknown. Marine crustaceans are parasitized by two orders of dinoflagellates: the Blastodinida and the Syndini...
Data on the morphology of the egg, mature larva (L3) and pupa of Squamapion elongatum (Germar, 1817) are presented. The development cycle of this species lasts 51-54 days: a 12-day egg period, a 30-day larval period, and a 12-day pupal period, on average. The larvae are attacked by parasitic hymenopterans of the superfamily Chalcidoidea.
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