Regular Article

Cell and Tissue Research

, Volume 316, Issue 3, pp 377-390

First online:

Retinal and optical adaptations for nocturnal vision in the halictid bee Megalopta genalis

  • Birgit GreinerAffiliated withDepartment of Cell and Organism Biology, Lund University Email author 
  • , Willi A. RibiAffiliated withUniversity of Human Sciences of the Principality of Liechtenstein
  • , Eric J. WarrantAffiliated withDepartment of Cell and Organism Biology, Lund University

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


The apposition compound eye of a nocturnal bee, the halictid Megalopta genalis, is described for the first time. Compared to the compound eye of the worker honeybee Apis mellifera and the diurnal halictid bee Lasioglossum leucozonium, the eye of M. genalis shows specific retinal and optical adaptations for vision in dim light. The major anatomical adaptations within the eye of the nocturnal bee are (1) nearly twofold larger ommatidial facets and (2) a 4–5 times wider rhabdom diameter than found in the diurnal bees studied. Optically, the apposition eye of M. genalis is 27 times more sensitive to light than the eyes of the diurnal bees. This increased optical sensitivity represents a clear optical adaptation to low light intensities. Although this unique nocturnal apposition eye has a greatly improved ability to catch light, a 27-fold increase in sensitivity alone cannot account for nocturnal vision at light intensities that are 8 log units dimmer than during daytime. New evidence suggests that additional neuronal spatial summation within the first optic ganglion, the lamina, is involved.


Visual system Nocturnal vision Apposition compound eye Retina structure Dim light Megalopta genalis (Insecta)