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In hymenopterans, males are normally haploid (1n) and females diploid (2n), but individuals with divergent ploidy levels are frequently found. In species with 'complementary sex determination' (CSD), increasing numbers of diploid males that are often infertile or unviable arise from inbreeding, presenting a major impediment to biocontrol breeding. Non‐CSD species, which are common in some parasitoid wasp taxa, do not produce polyploids through inbreeding. Nevertheless, polyploidy also occurs in non‐CSD Hymenoptera. As a first survey on the impacts of inbreeding and polyploidy of non‐CSD species, we investigate life‐history traits of a long‐term laboratory line of the parasitoid Nasonia vitripennis (Walker) (Hymenoptera: Pteromalidae) ('Whiting polyploid line') in which polyploids of both sexes (diploid males, triploid females) are viable and fertile. Diploid males produce diploid sperm and virgin triploid females produce haploid and diploid eggs. We found that diploid males did not differ from haploid males with respect to body size, progeny size, mate competition, or lifespan. When diploid males were mated to many females (without accounting for mating order), the females produced a relatively high proportion of male offspring, possibly indicating that these males produce less sperm and/or have reduced sperm functionality. In triploid females, parasitization rate and fecundity were reduced and body size was slightly increased, but there was no effect on lifespan. After one generation of outbreeding, lifespan as well as parasitization rate were increased, and a body size difference was no longer apparent. This suggests that outbreeding has an effect on traits observed in an inbred polyploidy background. Overall, these results indicate some phenotypic detriments of non‐CSD polyploids that must be taken into account in breeding. [ABSTRACT FROM AUTHOR]

Population genetic analyses are especially relevant for species considered threatened or highly endemic and for which other forms of biological information are lacking. Patellapis doleritica is a recently described communally nesting halictid bee of conservation concern because it is rare and endemic to the Succulent Karoo of South Africa. Moreover, its dispersal is considered to be restricted by its specialised nesting requirements and inclement weather conditions during its limited annual flight period, traits which may be common to other bee species of the region. We hypothesised that gene flow in P. doleritica was low, leading to marked genetic differentiation. Using 7 microsatellites, we investigated its mating and population genetic structure in 258 individuals (171 females and 87 males) from 7 populations spanning most of its known range. Deviation from Hardy-Weinberg equilibrium (F = + 0.254) suggested P. doleritica to be inbred, as in many other communal nesting bee species. Global F (0.028) and global G′ (0.216) revealed modest but significant differentiation between most populations, even across the very limited range of the species (ca. 25 km), with one genetically extreme outlier population. Despite inbreeding, we detected a surprisingly low frequency of diploid males (2 %). Patellapis doleritica nevertheless deserves special conservation attention since it is an endemic species with a low overall abundance and therefore possibly prone to environmental change and local extinction. [ABSTRACT FROM AUTHOR]