The occurrence of an orange body coloured mutant, governed by a single somatic recessive gene of the cotton stainer, Dysdercus koenigii is reported. Both the strains did not show any quantitative difference in growth, development and reproductive biology. Males of the orange mutant lacked any special preference for females of orange mutant. Inheritance of the orange mutant in mixed population showed its relative stability at about 21% from F2 to F8 generations. The utility of the orange mutant for studies on population genetics and dynamics of the cotton stainer is discussed.
