Superparasitism Drives Heritable Symbiont Epidemiology and Host Sex Ratio in a Wasp

Parratt, SR, Frost, CL ORCID: 0000-0002-4370-8741, Schenkel, MA, Rice, A, Hurst, GDD ORCID: 0000-0002-7163-7784 and King, KC (2016) Superparasitism Drives Heritable Symbiont Epidemiology and Host Sex Ratio in a Wasp. PLoS Pathogens, 12 (6). e1005629-.

Access the full-text of this item by clicking on the Open Access link.

Other journal.ppat.1005629.PDF - Published version Download (2MB)

Abstract

Heritable microbial symbionts have profound impacts upon the biology of their arthropod hosts. Whilst our current understanding of the dynamics of these symbionts is typically cast within a framework of vertical transmission only, horizontal transmission has been observed in a number of cases. For instance, several symbionts can transmit horizontally when their parasitoid hosts share oviposition patches with uninfected conspecifics, a phenomenon called superparasitism. Despite this, horizontal transmission, and the host contact structures that facilitates it, have not been considered in heritable symbiont epidemiology. Here, we tested for the importance of host contact, and resulting horizontal transmission, for the epidemiology of a male-killing heritable symbiont (Arsenophonus nasoniae) in parasitoid wasp hosts. We observed that host contact through superparasitism is necessary for this symbiont’s spread in populations of its primary host Nasonia vitripennis, such that when superparasitism rates are high, A. nasoniae almost reaches fixation, causes highly female biased population sex ratios and consequently causes local host extinction. We further tested if natural interspecific variation in superparasitism behaviours predicted symbiont dynamics among parasitoid species. We found that A. nasoniae was maintained in laboratory populations of a closely related set of Nasonia species, but declined in other, more distantly related pteromalid hosts. The natural proclivity of a species to superparasitise was the primary factor determining symbiont persistence. Our results thus indicate that host contact behaviour is a key factor for heritable microbe dynamics when horizontal transmission is possible, and that ‘reproductive parasite’ phenotypes, such as male-killing, may be of secondary importance in the dynamics of such symbiont infections.

Item Type:	Article
Uncontrolled Keywords:	Animals, Wasps, Proteobacteria, Sex Ratio, Symbiosis, Female, Male, Disease Transmission, Infectious
Depositing User:	Symplectic Admin
Date Deposited:	01 Jul 2016 15:49
Last Modified:	19 Jan 2023 07:34
DOI:	10.1371/journal.ppat.1005629
Open Access URL:	http://journals.plos.org/plospathogens/article?id=...
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3002003