Reproductive investment strategies in genetically invariant ants Vollenhovia emeryi

In clonally reproducing ants Vollenhovia emeryi, daughter queens and male offspring are nearly identical to their respective parental genome, whereas workers are equally related to their father and mother, but sterile.  The unusual reproductive modes in V. emeryi ants provide insight to understand the conflict between relatedness and genetic variability.

We describe the further reduction of genetic variability and colony caste investment in a non-native population of V. emeryi collected near Washington D.C. In this population all queens share a single genotype, all workers share a heterozygous genotype, and all males share a single genotype.  Thus, variability in colony size and investment of castes therein are due to environment differences and not due to genetic differences between colonies.  Sex ratios vary significantly between colonies, but arise near a 1:1 ratio at population level.  We provide correlative support for the trade-off between inclusive fitness strategies and the importance of worker genetic heterogeneity using field collected colonies in non-native populations near Washington D.C.

Vollenhovia emeryi colony investments differ in that they have highly variable sex ratios, have multiple queen colonies, vary in caste proportions, and have morphological size differences in queens.  Colony level differences in caste investment predicts that queens control caste production and may do so with trade-offs between numbers of produced offspring and size of offspring produced.  We investigate counts of entire colonies and morphological measurements of queens produced in each colony as a proxy to resource investment strategies in V. emeryi.