Math 225

Introduction to Biostatistics

Flea Beetles

Data were collected on the genus of flea beetle Chaetocnema, which contains three species: concinna (Con), heikertingeri (Hei), and heptapotamica (Hep). Measurements were made on the width and angle of the aedeagus of each beetle. The aedeagus is the median lobe of the male genital capsule that is surrounded by the phallobase and through which the sperm duct traverses.

The goal of the original study was to form a classification rule to distinguish the three species.

Picture of Aedeagus of Flea Beetle
Diagram of Aedeagus of Flea Beetle

The flea beetle data set has three variables.

Name Description
Width The maximal width of aedeagus in the forpart (in microns) .
Angle The front angle of the aedeagus (1 unit = 7.5 degrees).
Species Species of flea beetle from the genus Chaetocnema.

Name	Description
Width	The maximal width of aedeagus in the forpart (in microns) .
Angle	The front angle of the aedeagus (1 unit = 7.5 degrees).
Species	Species of flea beetle from the genus Chaetocnema.

The data is Beetle data.

References

Lubischew, A.A. (1962) On the use of discriminant functions in taxonomy. Biometrics, 18, 455-477.

Hand, D.J., et al. (1994) A Handbook of Small Data Sets, London: Chapman & Hall, 254-255.

Last modified: January 16, 2001

Bret Larget, larget@mathcs.duq.edu