Cubital index

cubital index

Part of fore wing of honey bee worker used for measurements of cubital index. (scale bar = 1 mm)


The cubital index was used, mainly by beekeepers, to discriminate honey bee subspecies. The discrimination using cubital index is relatively imprecise because it is based on measurements of only two distances [1][2]. More precise methods of subspecies discrimination require large number of measurements [3][4].
Selection for high cubital index by A. m. carnica breeders in Germany lead to unusually high cubital index in commercially available breeding lines of this subspecies [2]. There are various methods of measuring cubital index [5].

There are many conflicting definitions of cubital index. Probably this term was used for the first time by Alpatov [6]. Cubital index according to Alpatov (CIAlpatov) is expressed in percent:
CIAlpatov = 100 dAB/dBC
where:
dAB - distance between points A and B
dBC - distance between points B and C

Cubital index according to Goetze (CIGoetze1) [7] is:
CIGoetze1 = dbC/dAb
where:
dbC - distance between points b and C
dAb - distance between points A and b

Goetze [7] introduced also another variation of this index called "realer Cubital Index" (CIGoetze2):
CIGoetze2 = dBC/dAB

The last definition was generally accepted in Western Europe, while in Eastern Europe definition of Alpatov was used.

In book of Ruttner [3] (an important source of information about honey bee measurements) there is an error in description of cubital index - in figure 4.7 [3] - points B and C are swapped.

Cubital index of workers from species of genus Apis:

  • A. cerana 3.98 (Ruttner 1988, Tab. 1.1) [3], 2.63 - 7.86 (Ruttner 1988, Tab. 9.5) [3]
  • A. dorsata 7.25 (Ruttner 1988, Tab. 1.1) [3]
  • A. florea 2.82 (Ruttner 1988, Tab. 1.1) [3]
  • A. mellifera 1.53 - 3.60 (Ruttner 1988, Tab. 4.1) [3].

Cubital index of workers from subspecies of A. mellifera:

  • A. m. adami 1.89±0.18 (Ruttner 1988, Tab. 11.1) [3]
  • A. m. adansonii 2.39±0.41 (Ruttner 1988, Tab. 12.2) [3]
  • A. m. armeniaca 2.61±0.42 (Ruttner 1988, Tab. 11.1) [3]
  • A. m. anatoliaca 2.24±0.18 (Ruttner 1988, Tab. 11.1) [3]
  • A. m. capensis 2.33±0.34 (Ruttner 1988, Tab. 12.2) [3]
  • A. m. carnica 2.59±0.42 (Ruttner 1988, Tab. 14.1), 2.51 - 2.86 (Ruttner 1988, Tab. 14.2) [3], 2.94 in some commercial breeding lines [2].
  • A. m. caucasica 2.16±0.31 (Ruttner 1988, Tab. 11.1) [3]
  • A. m. cecropia 3.11±0.57 (Ruttner 1988, Tab. 14.1) [3]
  • A. m. cypria 2.72±0.36 (Ruttner 1988, Tab. 11.1) [3]
  • A. m. iberiensis 1.84±0.27 (Ruttner 1988, Tab. 13.1) [3]
  • A. m. intermissa 2.33±0.36 (Ruttner 1988, Tab. 13.1) [3]
  • A. m. lamarckii 2.37±0.37 (Ruttner 1988, Tab. 12.2) [3]
  • A. m. ligustica 2.55±0.41 (Ruttner 1988, Tab. 14.1) [3]
  • A. m. litorea 2.25±0.41 (Ruttner 1988, Tab. 12.2) [3]
  • A. m. macedonica 2.59±0.41 (Ruttner 1988, Tab. 14.1) [3]
  • A. m. mellifera 1.84±0.28 (Ruttner 1988, Tab. 13.1) [3]
  • A. m. meda 2.56±0.72 (Ruttner 1988, Tab. 11.1) [3]
  • A. m. monticola 2.35±0.41 (Ruttner 1988, Tab. 12.2) [3]
  • A. m. sahariensis 2.62±0.41 (Ruttner 1988, Tab. 13.1) [3]
  • A. m. scutellata 2.52±0.46 (Ruttner 1988, Tab. 12.2) [3]
  • A. m. siciliana 2.47±0.42 (Ruttner 1988, Tab. 14.1) [3]
  • A. m. syriaca 2.28±0.37 (Ruttner 1988, Tab. 11.1) [3]
  • A. m. unicolor 2.79±0.42 (Ruttner 1988, Tab. 12.2) [3]
  • A. m. jemenitica 2.20±0.40 (Ruttner 1988, Tab. 12.2), 2.20 - 2.45 (Ruttner 1988, Tab. 12.3) [3]

Cubital index differs between queens, workers and drones. In honey bee drones cubital index ranges from 1.38 to 1.93 (Ruttner 1988, Tab. 11.4) [3].

References