Hygroregulation, a key ability for eusocial insects: Native Western European honeybees as a case study

PLoS One. 2019 Feb 8;14(2):e0200048. doi: 10.1371/journal.pone.0200048. eCollection 2019.

Abstract

Sociality has brought many advantages to various hymenoptera species, including their ability of regulating physical factors in their nest (e.g., temperature). Although less studied, humidity is known to be important for egg, larval and pupal development, and also for nectar concentration. Two subspecies of Apis mellifera of the M evolutionary lineage were used as models to test the ability of a superorganism (i.e. honeybee colony) to regulate the humidity in its nest (i.e. "hygroregulation hypothesis") in four conservation centers: two in France (A. m. mellifera) and two in Portugal (A. m. iberiensis). We investigated the ability of both subspecies to regulate the humidity in hives daily, but also during the seasons for one complete year. Our data and statistical analysis demonstrated the capacity of the bees to regulate humidity in their hive, regardless of the day, season or subspecies. Furthermore, the study showed that humidity in beehives is stable even during winter, when brood is absent, and when temperature is known to be less stable in the beehives. These results suggest that humidity is important for honeybees at every life stage, maybe because of the 'imprint' of the evolutionary history of this hymenopteran lineage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bees / metabolism*
  • France
  • Humidity
  • Insecta
  • Larva / metabolism
  • Portugal
  • Seasons
  • Temperature

Grants and funding

This work was supported in part by the research project BEEHOPE funded by the European call for projects 2013-2014 BiodivERsA / FACCE-JPI from research agencies of France (ANR-14-EBID-0001), Spain (PCIN-2014-090) and Portugal (BiodivERsA / 0002/2014). I. Eouzan is financed by a doctoral grant from the Ministry of National Education, Higher Education and Research (France).