As a result of parasitism by Glyptapanteles liparidis in the first second third and, fourth instar larvae of Acronicta rumicis, the mortality of each larval stage was found to be 46.67, 90, 71 and 16.67%, respectively. The mortality was highest when G. liparidis parasitized the second and third instar larvae. The difference in mortality between the parasitized group and the control group was 72.14% in the second instar larvae. With regards to the food consumption of the parasitized larvae, the first and second instar larvae consumed 6495.58 [plus or minus] 646.52 mm2 (leaf surface) and 7951.12 [plus or minus] 4167.36 mm2, respectively, while the third and fourth larvae consumed 13 826.77 [plus or minus] 3396.66 mm2 and 18 599.85 mm2, respectively, showing that food consumption increased with instar stages of the host larvae. The clutch size of G. liparidis increased in relation to the instar stages of the host: it was 25.25 [plus or minus] 7.89, 48.65 [plus or minus] 53.75, 91.09 [plus or minus] 44.52 and 114 individuals when they were fed with the first, second, third and the fourth instar larvae of the host, respectively. none