Genetic differentiation can be promoted allopatrically by geographic isolation of populations due to limited dispersal ability and diversification over time or sympatrically through, for example, host-race formation. In crop pests, the trading crops across world lead intermixing genetically distinct pest populations. However, our understanding importance allopatric sympatric genetic in face anthropogenic is limited. Here, we examined global sequence variation two mitochondrial one nuclear...

Animals exploiting their familiar food items often avoid spatio-temporal aggregation with others by avoiding scents, less rewarding areas or visual contacts, thereby minimizing competition interference when resources are replenished slowly in patches. When animals searching assessing available sources, however, they may benefit from reducing sampling costs following at sites. Therefore, adjust responses to depending on familiarity foraging situations. Here, we conducted field experiments...

Summary Spatio‐temporal variation in resource availability is often large and unpredictable. When animals need to find sample novel foods, therefore they may prefer choose food sources with feeding conspecifics or odour left by the conspecifics. This behaviour (local enhancement) would be favoured, especially if it decreases time spent on food‐finding subsequent decision‐making. In laboratory experiments we tested naive bumble bees use local enhancement, what degree could reduce finding...

Wolbachia endosymbionts are widespread among insects and other arthropods, often causing cytoplasmic incompatibility reproductive phenotypes in their hosts. Recently, possibilities of Wolbachia-mediated pest control management have been proposed, the bean beetles subfamily Bruchinae known as serious pests harvested stored beans worldwide. Here we investigated infections from world, representing seven genera, 20 species 87 populations. Of examined, were detected four species, Megabruchidius...

When males of the flour beetle, Tribolium castaneum, are crossed to females its close relative T. freemani, sex ratio hybrids is female biased, owing in part hybrid male mortality. Morphological abnormalities also frequent surviving males, but not females. The finding that heterogametic (male) more adversely affected interspecific crosses than homogametic consistent with Haldane's rule, which predicts dysfunction should emerge as an indirect byproduct divergent adaptation differing...

Summary Competition between contest and scramble strategists was examined using two strains of Callosobruchus maculatus , the strain (iQ) (tQ). The direct larval interference experiment within each showed that performed strong throughout its stage against conspecific opponent(s). also interference, but only during 3rd 4th stages. inter‐strain competition experiments inside a large small mung bean ( Vigna radiata ) was, in general, superior to competition, results were density‐...

Summary Larval competition curves and resource sharing patterns of 5 strains Callosobruchus maculatus (iQ, yQ, aaQ, wQ, tQ) were examined. Offspring emergences as a function the initial larval density recorded to construct curves. Elytron length emerged adults was used indicator among competing larvae inside bean. In large beans, strain iQ showed saturated curve tQ humped curve. Competition other 3 (yQ, wQ) between those two extremes. small also curves, respectively, whereas intermediate...

Abstract Callosobruchus maculatus has both contest and scramble competition strategies. The currently existing theoretical models using game theory suggest that the strategy should be selected for. However, most geographic strains of C. show competition. We experimentally crossed representative scramble. expressed degree by a continuous value named C ‐value, which ranges from zero (pure scramble) to unity contest). types in ‐value were genetically additive. Their larval developmental rates...

Habitat selection in avian species is a hierarchical process driven by different factors acting at multiple scales. preferences and site fidelity are two main affecting how colonial birds choose their breeding locations. Although these affect habitats, previous studies have only focused on one factor time to explain the distribution of regional Here we used 28 yr colony location data herons egrets around Ibaraki prefecture Japan order analyze relative importance habitat for selecting We...

Group foraging and colonial formation in avian species are examined with an artificial life (alife) model using genetic algorithms (GA) neural networks. Horn's classical predicts that birds more successful than territorial ones a patchy resource environment, the reverse is true when resources evenly distributed. The weak point of confusion between colony flock implicit assumption perfect knowledge distribution by birds. authors made alife realized both simultaneously during evolution...

Abstract We tested experimentally the effects of genetic variation in host population on host‐parasitoid system persistence. The experimental systems consisted one parasitoid wasp species ( Heterospilus prosopidis ), bean weevil Callosobruchus chinensis and species, which only (bean weevil) was genetically manipulated. As control treatments with low heterogeneity population, we used two strains (Kyoto Niigata strains) have several contrasting ecological traits. For high treatment, hybrid...

Abstract W olbachia cannot live outside a host, which is thought to be the reason for host‐ coevolution toward benign parasitism, especially because fitness of traded against its host's fitness. Insect melanism has been reported have positive effect on pathogen resistance, but melanic mutants C allosobruchus analis ( F abricius) and chinensis (L.) oleoptera: hrysomelidae) are infected with . CI ‐inducing , exhibit decline. Interestingly, this decline not observed in that ‐free Our research...

Abstract The seed beetle Callosobruchus maculatus larvae exhibit two types of resource competition: scramble, in which a is shared, and contest, the monopolized. This difference larval behavior results different adult densities. Under contest competition, density remains constant regardless density, but under scramble increases with density. turn affects mating frequency during adulthood, thus, intensity sexual selection operating on males. In this study, we examined relationship between...

Plant–animal mutualistic networks are characterized by highly heterogeneous degree distributions. The majority of species interact with few partner species, while a small number connected to form network hubs that proposed play an important role in community stability. It has not been investigated, however, if or how the distributions vary among types mutualisms communities, between plants and animals same network. Here, we evaluate pollination seed-dispersal networks, which two major have...

Larvae of Callosobruchus maculatus (F.) can coexist in a bean and exhibit scramble-type competition although the larvae kill each other. Mechanisms to prevent or neutralize interference should be necessary for competition. Previous studies reported that C. make walls fill their intersections after they encounter other bean. To examine whether wall-making is related mechanism behind maculatus, we examined larval behavior geographically isolated strain, which but retain ability. We conducted...