The effects on the development and protein levels in the larvae of male Pimpla turionellae L. of different amounts of B group vitamins namely thiamin, riboflavin, Ca-pantothenate, nicotinic acid, pyridoxine-HCl, folic acid and biotin and a growth factor choline chloride in the meridic diet were investigated. Among the vitamins tested, choline chloride and biotin were found to have quantitatively critical values in the diet and increased amounts of nicotinic acid and folic acid individually in the control diet showed positive effects on development and protein levels. A decrease in the levels of Ca-pantothenate and pridoxine-HCl caused decreases in protein levels, whereas variations in the levels of thamin and riboflavin did not have any significant effect. none