Behavioural manipulation of insect hosts by Baculoviridae as a process of niche construction

Abstract

BackgroundNiche construction has received increasing attention in recent years as a vital force in evolution and examples of niche construction have been identified in a wide variety of taxa, but viruses are conspicuously absent. In this study we explore how niche construction can lead to viruses engineering their hosts (including behavioural manipulation) with feedback on selective pressures for viral transmission and virulence. To illustrate this concept we focus on Baculoviridae, a family of invertebrate viruses that have evolved to modify the feeding behaviour of their lepidopteran hosts and liquefy their cadavers as part of the course of infection.ResultsWe present a mathematical model showing how niche construction leads to feedback from the behavioural manipulation to the liquefaction of the host, linking the evolution of both of these traits, and show how this association arises from the action of niche construction. Model results show that niche construction is plausible in this system and delineates the conditions under which niche construction will occur. Niche construction in this system is also shown to be sensitive to parameter values that reflect ecological forces.ConclusionsOur model demonstrates that niche construction can be a potent force in viral evolution and can lead to the acquisition and maintenance of the behavioural manipulation and liquefaction traits in Baculoviridae via the niche constructing effects on the host. These results show the potential for niche construction theory to provide new insights into viral evolution.

Spreading vampirism: Viral disease models in Buffy the Vampire Slayer

“…Baculoviridae, for instance, is a virus that causes infected caterpillars to increase their food consumption, providing more nutrients that allow the virus to quickly replicate. Once completed, the infected caterpillar is encouraged to travel to an elevated area where it is liquefied and dispersed to further spread the virus to other caterpillars [13,14]. The pathways associated with similar phenomena in humans would be complex, but can be partially blocked by removable brain implants (B:S4E7), implying some form of localization.…”