What stops the `diploid male vortex'?-A simulation study for species with single locus complementary sex determination

Authored by Hans Joachim Poethke, Silke Hein, Silvia Dorn

Date Published: 2009

DOI: 10.1016/j.ecolmodel.2009.04.001

Sponsors: German Research Foundation (Deutsche Forschungsgemeinschaft, DFG)

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

The survival of hymenopteran populations especially that of ecologically and economically important pollinators and parasitoids, has become a major topic for empirical and theoretical studies. Complementary sex determination (CSD) in Hymenoptera may impose a substantial genetic load through the production of inviable or sterile diploid males. Modelling and laboratory studies have indicated that this genetic load may trigger a `diploid male vortex' leading to rapid extinction of populations. Here we take a broader theoretical approach to analyze why populations exhibiting CSD persist in nature, even if they contain large proportions of homozygous diploid individuals. Using an individual-based model of spatially structured hymenopteran populations, we show that (i) inviability or reduced fertility of homozygous individuals, (ii) female-biased sex ratio, and (iii) strong intra-specific competition can mitigate the negative influence of CSD on population persistence and that (iv) already extremely low dispersal rates will result in long term survival. These findings underline the importance of life history traits for population survival and demonstrate that rather specific conditions must be met to initiate the `diploid male vortex'. (C) 2009 Elsevier B.V. All rights reserved.
Tags
Evolution Density-dependent dispersal Hymenoptera Populations Mating system Primitively eusocial bee Cotesia-glomerata Parasitoid wasp Bracon-hebetor Honey bees