| Popis: |
The work is based on population samples from northern and western Europe and on laboratory rearings. The traditional forms lineata, redimita and ovata do not represent true polymorphic phases. There is also continuous variation between the forms redimita and ovata. The red pattern appears either during the third instar or at maturation ecdysis. These red patterns, called red I and red II, are independent. In Finnish populations the males lack the red II. There is a slight difference in the fecundity of the colour forms. The earlier proposed genetic basis of the colour polymorphism, viz. one pair of alleles without dominance, is wrong. The polymorhism is based on apparently two different genes, both of which seem to be dominant. The red coloured phenotypes are generally more common in Finland than in the other European populations; the lowest frequency was found in the Swiss Alps. The frequencies are temporally stable in populations, as proposed earlier. There is a slight indication that the characteristics of the habitat and the colour form frequencies are correlated. |
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