Komplementäre Geschlechtsbestimmung bei Brackwespen : Inzuchtdepression und Inzuchtvermeidung

Abstract

In species with single-locus complementary sex determination (sl-CSD), sex is determined by multiple alleles at a single locus. In haplodiploid Hymenoptera (ants, bees and wasps), sl CSD results in females, if individuals are heterozygous at the sex locus, and in males, if individuals are hemizygous (haploid males) or homozygous (diploid males). Sterile, diploid males are considered an evolutionary dead end and female wasps should avoid producing diploid sons, i.e. they should avoid mating with males that carry a matching sex allele. Gregarious species, that lay clutches of eggs, have an elevated risk of sib-mating. In addition, the survival probability of small and isolated population can be altered depending on the viability of diploid males. I investigated the effect of inbreeding on two Bracon species, one with viable diploid males and one with a high diploid male mortality. In further experiments I focused on possible inbreeding avoidance strategies that could be used to reduce the production of diploid males and triploid females in Bracon brevicornis.