Two parasitoids collected during a survey were tested for their suitability as control agents against Pentalonia nigronervosa Coq. Aphidius absinthii Marshall and Trioxys (Binodoxys) communis Gahan successfully parasitized P nigronervosa under laboratory and greenhouse conditions. Under laboratory conditions, the mean value for parasitization efficiency of A, absinthii given a host density of 10 aphids was 1.71 [plus or minus] 0.95 while that of T (B.) communis was 2.23 [plus or minus] 0.08. When the host density was increased to 20 aphids, the mean value for parasitization efficiency increased to 2.19 [plus or minus] 0.07 for A. absinthii and 3.42 [plus or minus] 0.12 for T (B.) communis. In the greenhouse, the mean values for parasitization efficiency were lower for both parasitoids. Parasitization of P. nigronervosa occurred, on the average, 9.73 [plus or minus] 0.33 days after the introduction of both parasitoids in the greenhouse. Under laboratory conditions, parasit! ization took significantly longer for both parasitoids, 14.14 [plus or minus] 0.48 days for A. absinthii and 14.1 [plus or minus] 0.48 for T (B.) communis. Total developmental periods of the two parasitoids differed under the two experimental conditions. They were longer in the laboratory than in the greenhouse which could be attributed to the limited space and food supply. The parasitoids, having more space and aphids to feed on, developed faster in the greenhouse. However, those in the laboratory lived longer than those reared in the greenhouse. Pentalonia nigronervosa (Aphidoidea): Host, Parasite; Aphidius absinthii (Aphidiidae): Parasite; Trioxys (Binodoxys) communis (Aphidiidae): Parasite. Aphidius absinthii, Trioxys (Binodoxys) communis: Biological control, Suitability as biocontrol agent, Hemipteran hosts, Pentalonia nigronervosa; Pentalonia nigronervosa: Biological control, Hymenopteran parasites, Aphidius absinthii, Trioxys (Binodoxys) communis, Plant hosts, Hymenopteran parasites as biocontrol agents. Arthropods; Hymenopterans; Insects; Invertebrates; True Bugs. none