The Genetic Basis of Dispersal Behavior in the Flour Beetle Tribolium Castaneum

Flour beetles of the genus Tribolium are suitable for the study of dispersal. In an attempt to gain an understanding of the genetic basis of this trait in T. castaneum, a two-way selection experiment was carried out, for 11 successive generations, in a stock derived from an Israeli wild population. When dispersants were defined as beetles that disperse more than once in several attempts, separation between the lines was achieved after one generation of selection. The difference between the lines remained more or less constant in subsequent generations of selection, and did not disappear when selection was relaxed. Reciprocal crosses between the lines suggest that the tendency to disperse is determined by the genotype at a single, sex-linked locus. The allele for dispersal is dominant. Males tend to disperse more readily than females of equivalent genotypes.