Solitary and group nesting in the orchid bee Euglossa hyacinthina (Hymenoptera, Apidae)

Abstract

Orchid bees (Euglossini) provide a potentially informative contrast for examining origins of advanced social behaviour in bees because they are the only tribe in the apine clade that do not form large colonies or have queens and workers. We investigated natural nests of Euglossa hyacinthina Dressler, an orchid bee that nests singly or in groups. By comparing the two types of nests, we examined if individuals in a group merely share the nest (are communal) or exhibit a level of social organization where there is reproductive division of labour among the females. Observations are consistent with communal nesting, indicating that all females in group nests are reproductively similar to the solitary nesting females because the provisioning of young, as well as the ovary development and mating status of females sharing nests were not different than that of solitary-nesting females. Also, multiple female nests did not produce a female-biased brood as predicted for nests with reproductive division of labour. We also investigated potential advantages of group nesting vs. individual nesting. We demonstrate that per capita offspring production is lower in nests with more than one female. However, we found that nests with single females were left unattended for longer periods of time during foraging, and that there was a high incidence of natural enemy attack in nests when females were absent. Group and solitary nesting may be advantageous under different conditions.

Influence of queen phenotype, investment and maternity apportionment on the outcome of fights in cooperative foundations of the ant Lasius niger

“…Joint nesting also increases colony fitness in other contexts, for example (5) by improving resistance to adverse abiotic conditions (temperature, precipitation;Tschinkel & Howard 1983;Pfennig 1995;Helms Cahan 2001), (6) by reducing costs associated with nest construction and maintenance (Pfennig 1995;Helms Cahan 2001) or (7) by allowing production of reproductives at an earlier stage (Vargo 1988). Similar benefits have been proposed to account for the evolution of cooperative foundations in other social insects, including termites (Thorne 1982), wasps (Strassmann et al 1988;Tibbetts & Reeve 2003), bees (Soucy et al 2003) and thrips (Morris et al 2002;Bono & Crespi 2006).…”

The Ecological Basis for Biogeographic Classification: an Example in Orchid Bees (Apidae: Euglossini)

“…For the purpose of categorization, social behavior was determined as follows: Aglae and Exaerete were classified as parasitic (Cameron 2004, Garófalo 2006, Nemésio and Silveira 2006, Eufriesea as solitary (Kimsey 1982, Cameron 2004, Garófalo 2006, Euglossa as communal-solitary (Eberhard 1989, Soucy et al 2003, Augusto & Garófalo 2004, and Eulaema as communal (Bennett 1965, Santos & Garófalo 1994, Cameron 2004). …”

“…Eufriesea Cockerell is predominantly solitary, although cooperative forms are reported (Kimsey 1982, Eberhard 1989, Garófalo 1994, Soucy et al 2003. More complex levels of cooperation exist in Eulaema Lepeletier and Euglossa Latreille (Bennett 1965, Santos & Garófalo 1994, Augusto & Garófalo 2004.…”

“…The available evidence strongly suggests that the euglossine bees are by no means strictly solitary (Soucy et al 2003, Augusto & Garófalo 2004, Garófalo 2006, Otero et al 2008, Cocom-Pech et al 2008.…”

Evolución de la sociabilidad en Hymenoptera: Rasgos conductuales vinculados a niveles sociales y precursores de sociabilidad en especies solitarias

“…Si falta un marco fi logenético de referencia, las proposiciones sobre el cambio del estado de caracteres son afirmaciones que dependen de suposiciones a priori sobre cómo la evolución debería proceder (Wcislo & Danforth 1997). Idealmente, estas entidades fi logenéticas (Wcislo 1997b) deben ser aquellas en que existen especies con diversidad de niveles sociales incluyendo especies no sociales (Schwarz et al 2007) pues, mientras las investigaciones en especies altamente sociales son informativas respecto de la mantención del comportamiento social, el estudio de especies emparentadas cercanamente, que exhiben vida solitaria o semisocial, es necesario para comprender el origen de la organización altamente social (eusocial) (Soucy et al 2003).…”