Glasshouse studies were conducted to ascertain the effects of nutrient solutions of calcium and phosphorus on the growth and development of rose grain aphid, Metopolophium dirhodum (Walker) and its parasitoid Aphidius rhopalosiphi (De Steph.). High calcium and high phosphorus concentrations applied to a partially resistant wheat cultivar “Rapier” did not have a significant effect on the growth and development of the aphid or its parasitoid. However, the mean fecundity of the parasitoid was higher on plants with high phosphorus than those treated with high calcium concentrations.