Genetic Studies of a Morphological Character That Separates Two Species of Blattella (Dictyoptera: Blattellidae)

The tenth tergite (T₁₀) of male Blattella asahinai is narrower than that of B. germanica. The trait is intermediate in F_x hybrids. Backcross data suggest a quantitative genetic basis for T₁₀ variation, although the possibility that a major locus was hidden by the variability could not be ruled out. Reciprocal backcrosses to B. germanica, but not those to B. asahinai, differed significantly.