The wings of insects are stiffed by veins

The arrangement of these veins is characteristic for any insect. Therefore, it is possible to discriminate races by measurements at the veins.

In the front wing of the bees is the long radial cell R. Underneath the radial cell are three cubital cells called C1, C2 and C3. Underneath the cubital cell C2, C3 is the discoidal cell D.

The Cubitalindex

is measured in the cubital cell C3. It is the most important racial characteristic with bees. The lower limitation of the 3rd cubital cell is divided into two sections (a and b) by the right limitation of the discoidal cell.

The Cubitalindex is the relation from a / b.

A criterion for the judgement is the mean value of the Cubitalindex.

Besides, in addition, the smallest and the biggest value are given in clips:

 

Mean value = 2,98 (1,8 – 4,2)

 

One gets a more exact statement if (defined by RUTTNER) the Cubitalindex of the tested animals is distributed into classes, and is shown in a curve number of bees per class.

Flügel-Index computes the classes with one digit after the comma.

The value behind the comma indicates the position within the class - 0 means the index is near to the lower class and 9 means the index is near to the next class.

The Hantelindex

is also measured at the 3rd Cubital cell.

The Hantelindex is the relation from c / d.

A criterion for the judgement is the mean value of the Hantelindex. Besides, in addition, the smallest and the biggest value are given in clips:

Mean value = 0,94 (0,8 – 1,2)

A more exact statement you get if (defined by KRUBER) the Hantelindex of the tested animals is distributed into classes and is shown in a curve number of bees per class.

Flügel-Index computes the classes with one digit after the comma.

The value behind the comma indicates the position within the class - 0 means the index is near to the lower class and 9 means the index is near to the next class. 

The Discoidalshift

With the measurement of the Discoidalshift a length and not the relation of two lengths is measured.

Therefore, only with the scanner dissolution which is given under Options - Measurement (1200 or 2400dpi) a correct measurement is possible.

For the measurement of the Discoidalshift a line is drawn along the radial cell. In an angle of 90 ° a second line which goes through the point H is drawn. The Discoidalshift is the distance from the point Di to the second line in 1/20 mm.

There are positive and negative values. A positive value appears if the point Di lies in direction to the wingtip.

The Discoidalshift is a strong distinctive mark between the Mellifera and the other European bee's races. The Discoidalshift of Mellifera bees is negative - the Discoidalshift of the other bee's is positive.

For the measurement of the Discoidalshift a measuring spider was given by KRUBER which causes a correction of the measured values with workers and drones. Flügel-Index corrects the measured values according to this measuring spider.

Diagram Cubitalindex – Discoidalshift

 

In some countries the Discoidalshift instead of the hair length is used to distinct the Mellifera from the other European bee's races.

 

A possibility of clear representation of the relations is a diagram showing the Cubitalindex and the Discoidalshift.

For each of the bees is a point in the diagram which represents both

The points of the Mellifera are placed left down and the points of the other European bee's races right up.

What is a Correlation?

With the frequently applied representation of a correlation of two values, one value (e. g. x) is applied in horizontal direction and the other value (e. g. y) in vertical direction.

The left picture shows a perfect correlation – y is exact twice x (e.g., x = 2 and y = 4) and the correlation points in the diagram are on the blue line.

In the nature only an imperfect correlation is possible (middle picture) - y is about twice x and the correlation points in the diagram are near the blue line.

In the right picture x and y are not correlated - the points are somewhere in the diagram.

Correlation of Hantelindex and Discoidalshift

KRUBER found out that the Hantelindex and the Discoidalshift of thoroughbred bees are correlated.

This occurs at  all races and he defined "trust areas" for the different races.

The trust area of the Mellifera lies at lower values, the trust area of Carnica and Ligustica at higher values of Hantelindex and Discoidalshift.

The trust area for workers is approximately symmetrical to the line of the perfect correlation. The trust area for drones is a little upwards.

Flügel-Index uses depending on the examination of workers or drones the appropriate trust area.