title: Cryptic extended brood care in the facultatively eusocial sweat beeMegalopta genalis.
abstract: As a result of different brood cell provisioning strategies, nest-making insects may differ in the extent to which adults regularly provide extended parental care to their brood beyond nest defense. Mass-provisioning species cache the entire food supply needed for larval development prior to the oviposition and typically seal the brood cell. It is usually assumed that there is no regular contact between the adult(s) and brood. Here, we show that the bee,Megalopta genalis, expresses a form of cryptic brood care, which would not be observed during normal development. Following experimental injections of different provisioning materials into brood cells, foundresses reopened manipulated cells and the brood were aborted in some cases, implying that the foundresses assessed conditions within the cells. In aborted cells, foundresses sometimes laid a second egg after first removing dead larvae, previously stored pollen and contaminants. Our results show that hygienic brood care can be cryptic and hence may be more widespread than previously believed, lending support to the hypothesis that extended parental care is a preadaptation toward eusociality.
authors.affiliation: Theoretical biology group, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
authors.forename: A E
authors.initials: AE
authors.lastname: Quiñones
authors.affiliation: Smithsonian Tropical Research Institute, 0843-03092 Balboa, Apartado Republic of Panama.
authors.forename: W T
authors.initials: WT
authors.lastname: Wcislo
keywords: Eusociality; Extended maternal care; Hygienic behavior; Megalopta genalis; Subsociality; Undertaking behavior