Overcoming drag at the water-air interface constrains body size in whirligig beetles

Ludovic Jami, Grey T. Gustafson, Thomas Steinmann, Miguel Piñeirua, Jérôme Casas

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Whirligig beetles (Coleoptera: Gyrinidae) are among the best swimmers of all aquatic insects. They live mostly at the water’s surface and their capacity to swim fast is key to their survival. We present a minimal model for the viscous and wave drags they face at the water’s surface and compare them to their thrust capacity. The swimming speed accessible is thus derived according to size. An optimal size range for swimming at the water’s surface is observed. These results are in line with the evolutionary trajectories of gyrinids which evolved into lineages whose members are a few milimeter’s long to those with larger-sized genera being tens of millimeters in length. The size of these beetles appears strongly constrained by the fluid mechanical laws ruling locomotion and adaptation to the water-air interface.

Original languageEnglish (US)
Article number249
Issue number7
StatePublished - Jul 2021


  • Gyrinidae
  • Locomotion
  • Phylogeny
  • Swimming insect
  • Thrust
  • Water sliders
  • Wave resistance

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes


Dive into the research topics of 'Overcoming drag at the water-air interface constrains body size in whirligig beetles'. Together they form a unique fingerprint.

Cite this