Field surveys in Arkansas soybean fields, 1974–76, indicated thatApanteles marginiventris(Cresson) is the most abundant parasite of green cloverworm larval populations andRogas nolophanaeAshmead is a parasite of secondary importance. Research from other soybean areas in the U.S. report these 2 parasites in reverse order of abundance. It is possible thatA. marginiventrishas an advantage overR. nolophanaein Arkansas since both species attack the same larval stages of the host.A. marginiventrisappears to be a very effective parasite of the green cloverworm in Arkansas.