Table 1.

Ecological data, body, ocellus and eye measurements, and the acceptance angles and optical sensitivities of single ommatidia, in four species of honeybees of genus Apis

SymbolA. melliferaA. ceranaA. floreaA. dorsata
Ecological data
   Temperature range (°C)>117>10.5118–431>151
   Light intensityHalf-moon in some subspecies7DaylightDaylightHalf-moon8
Body and eye measurements
   Intertegular width (mm)3.23.0±0.052.2±0.073.9±0.2
   Tongue length (mm)5.8–7.134.53±0.0123.41±0.0226.14±0.042
   Ocellus diameter (mm)0.2740.260.240.38±0.02
   Eye length (mm)2.642.1±0.11.7±0.052.8±0.1
   Length of sensory hairs on the eyes (μm)2759125±1450±6100±7
   Facet number per eye54326 47525500434846394
   Max. ommatidial diameter (μm) D 20524.519.529.5
   Corneal thickness (μm)27–38427-352546
   Crystalline cone length (μm)55503655
   Focal length (μm) f 6658479104
   Distal rhabdom diameter (μm) d
   Acceptance angle (deg.)Δρ1.751.21.11.8
   Rhabdom length (μm) I 3205270190260
   Optical sensitivity to white light (μm2 sr) S 0.1150.070.030.21
  • Data that were not obtained in this study are from 1Corlett, 2004; 2Oldroyd et al., 1992; 3Böttcher, 1977; 4Ribi et al., 1989; 5Greiner et al., 2004a; 6Seidl and Kaiser, 1981; 7Fletcher, 1978 on A. m. adansonii; 8Dyer, 1985; 9Neese, 1965. The acceptance angle Δρ was calculated from the ratio of the distal rhabdom diameter d to the focal length f, and optical sensitivity S was calculated using Eqn 2