Interspecific host competition and parasite virulence evolution

Abstract

Virulence, the harm to hosts caused by parasite infection, can be selected for by several ecological factors acting synergistically or antagonistically. Here, we focus on the potential for interspecific host competition to shape virulence through such a network of effects. We first summarize how host natural mortality, body mass changes, population density and community diversity affect virulence evolution. We then introduce an initial conceptual framework highlighting how these host factors, which change during host competition, may drive virulence evolution via impacts on life-history trade-offs. We argue that the multi-faceted nature of both interspecific host competition and virulence evolution still requires consideration and experimentation to disentangle contrasting mechanisms. It also necessitates a differential treatment for parasites with various transmission strategies. However, such a comprehensive approach focusing on the role of interspecific host competition is essential to understand the processes driving the evolution of virulence in a tangled bank.

Parthenogenesis affects interspecific competition between Megalurothrips usitatus and Frankliniella intonsa (Thysanoptera: Thripidae) in changing environment: evidence from life table study

“…Interspecific competition is a natural phenomenon in the relationship between species inhabiting the same niche ( Hasik et al 2023 , Wang et al 2023 ). Megalurothrips usitatus and F. intonsa are 2 species inhabiting the same cowpea niche.…”

Multispecies interactions and the community context of the evolution of virulence

“…Given the importance of disease spillover in multi-host, multi-parasite systems, 33–35 the question of which host communities may favor the evolution of high parasite virulence is critical. Recent work has begun to explore parasite evolution in more complex ecological contexts, such as hyperparasitism 36, 37 and multi-parasite assemblages, 38, 39 and has called for further exploration of the consequences of inter-host interactions on shared parasites, 40 but our theoretical understanding of the evolution of parasites in a realistic community context remains limited.…”

Coinfection accelerates transmission to new hosts despite no effects on virulence and parasite growth

“…Indeed, the virulence-transmission trade-off hypothesis posits that, despite virulence being a by-product of parasite growth, too much high virulence leads to excessive host damage, curtailing transmission [11,12]. Evidence for the existence of a trade-off between these traits is limited [13], possibly owing to environmental factors-such as host and/or parasite demography, interactions with the host immune system or coinfection-changing the selection environment and relationships between traits [1,3,12,14,15]. Therefore, coinfection may be a factor affecting traits involved in the trade-off and/or modulating the interaction among them [1,16].…”