Abstract Cytochrome oxidase subunit I (COXI) molecular characterization seems to lend credence to the specimen's identification as a stem fly, M. sojae, feeding on black gramme. This study is the first to report M. sojae as a pest of black gramme in India. The pest population in the black grame crop planted in the first and second weeks of March was low: 28.38 and 29.73% infestation, 8.92 and 9.45% tunnelling, 0.22 and 0.26 larvae/plant, and 0.27 and 0.27 pupae/plant. Infestation was low (22.69%) and tunnelling was low (3.85%) in the black gramme crop planted in the third week of July for the kharif harvest. In compared to crops planted in August, larval and pupal counts were lower in crops planted in the third and fourth weeks of July. The crop that was planted in the second week of March yielded the most seeds (597 kg/ha), followed closely by the crop planted in the first week of March (564 kg/ha). Seed and haulm yields were both highest for crops planted in the third week of July during the kharif season (806 and 429 kg/ha, respectively).