A population of herbivorous insects that shifts to a novel host can experience selection pressures that result in adaptation to the new resource. Host race formation, considered an early stage of the speciation process, may result. ! e current study investigates host shifts and variation in traits potentially involved in the evolution of reproductive isolation among populations of the juniper h...

Because weevils are used as biocontrol agents against thistles, it is important to document and understand host shifts and the evolution of host-specificity in these insects. Furthermore, such host shifts are of fundamental interest to mechanisms of speciation. The mediterranean weevil Larinus cynarae normally parasitizes either one of two thistle genera, Onopordum and Cynara, being locally mon...

Bean beetles (Bruchinae) are a taxon of seed predators and several species economically significant stored product pests. Seed quality may affect adult life history traits, with consequences for their population dynamics. We investigated if variation in host (poor quality: lentil; high mung bean) as experienced by the parental (i.e. individuals ovipositing) generation natal study emerging from ...

While the role of host preference in ecological speciation has been investigated extensively in terrestrial systems, very little is known in marine environments. Host preference combined with mate choice on the preferred host can lead to population subdivision and adaptation leading to host shifts. We use a phylogenetic approach based on two mitochondrial genetic markers to disentangle the taxo...

Few studies have examined the genetic architecture of population differences in behaviour and its implications for population differentiation and adaptation. Even fewer have examined whether differences in genetic architecture depend on the environment in which organisms are reared or tested. We examined the genetic basis of differences in oviposition preference and egg dispersion between Asian...

Widespread replacement of native ecosystems by productive land sometimes results in the outbreak of a native species. In New Zealand, the introduction of exotic pastoral plants has resulted in diet alteration of the native coleopteran species, Costelytra zealandica (White) (Scarabaeidae) such that this insect has reached the status of pest. In contrast, C. brunneum (Broun), a congeneric species...