Interspecific interactions in solitary Aculeata – is the presence of heterospecifics important for females establishing nests?

Abstract

There are several possible causes of aggregated nesting in solitary Aculeata, one being joint defense against parasites. We tested whether females prefer nesting in aggregations, even if they consist of heterospecifics. We compared the colonization and nesting parasitism of trap-nests with and without a red mason bee aggregation. The results did not support our hypothesis that females prefer nesting in aggregations. The numbers of wild Aculeata nests did not differ between trap-nests with and without an aggregation. Unexpectedly, parasitism rates were higher in trap-nests with aggregations. When analyzing only nests of wild insects (mostly wasps), the differences in parasitism disappeared. Natural nesting sites may be such a limited resource that females nested in the first trap-nest they encountered and did not discriminate between our treatments, or wasps might share too few parasites species with bees to benefit from joint nest defense.

Red mason bee (Osmia bicornis) thermal preferences for nest sites and their effects on offspring survival

“…This makes red mason bees good candidates for model species, e.g. in studies of pesticide toxicity, the effect of environmental pollution, ecological stoichiometry, or interspecific interactions (Fliszkiewicz et al 2012a;Szentgyörgyi et al 2017;Kierat et al 2018;Sgolastra et al 2019;Filipiak 2019;Eeraerts et al 2020). Females fly throughout the spring until early summer.…”

Effects of hillside aspect, landscape features, and kleptoparasitism on the reproductive success of the solitary bee Osmia caerulescens

“…The vials were kept in a refrigerator at 8 °C until March 2015, when they were placed at room temperature to elicit the emergence of the adults, which were killed for subsequent identification to species level and body size measurement. In some cases, no adults emerged, or all the brood cells were parasitised, so the nests were assigned to particular species considering both the presence of the species in the same trap‐nests and the architecture of the nests (Holzschuh et al ., 2009; Kierat et al ., 2018).…”