Melanagromyza obtusais a serious pest ofCajanus indicusin the Oriental region, particularly noticed in India, Java and Malaya. The mitotic and salivary gland chromosomes were studied for the first time. A map of its salivary gland chromosomes has been constructed and some identifiable land-marks in each arm of the chromosome are recognized. Analysis of population samples from three different geographical localities has yielded two overlapping paracentric inversions in the X-chromosome.