Host specificity testing is universally used in weed biological control to predict nontarget effects of potential agents. Despite this, there is some confusion regarding the role of host specificity testing in making such predictions. One possible role is as an assay of field host range. In this case, the ideal host specificity test will simulate conditions encountered in the field, and the res...

The evolution of host specificity remains a central issue in the study of host-parasite relationships. Here we tackle three basic questions about host specificity using data on host use by fleas (Siphonaptera) from 21 geographical regions. First, are the host species exploited by a flea species no more than a random draw from the locally available host species, or do they form a taxonomically d...

The degree to which parasites use hosts is fundamental to host-parasite coevolution studies, yet difficult to assess and interpret in an evolutionary manner. Previous assessments of parasitism in eugregarine-host systems suggest high degrees of host specificity to particular host stages and host species; however, rarely have the evolutionary constraints on host specificity been studied experime...

Kudoid parasites are known to infect a large variety of fish. A significant proportion of Kudoa species have relatively low host specificity, with a single species able to infect multiple host species representing various host families even from different host orders. Since DNA sequences have been associated with myxosporean species characterisations, it has become far easier to determine host ...

ventional monocultural crop systems often supported by high inputs of pesticides and fertilizers to sustainable agriculture. Although precise definitions of sustainable agriculture vary, one key aspect is a reduction in agrichemical inputs with a corresponding shift to alternative crop protection strategies, such as cultural practices, organic amendments, resistant or tolerant crop varieties, a...

The measurement of host specificity goes well beyond counting how many host species can successfully be used by a parasite. In particular, specificity can be assessed with respect to how closely related the host species are, or whether a parasite exploits the same or different hosts across its entire geographic range. Recent developments in the measurement of biodiversity offer a new set of ana...