Ricania simulans causes harm in almost all plants that grow along the Eastern Black Sea coast. The chemicals used to control this pest are prohibited in this region due to tea cultivation. For this reason, new strategies are needed to control this pest. With the awareness on the negative effects of the chemicals used in the control against pests and with the increasing awareness on environmental issues, alternative methods were sought in the past; and in this context, studies were conducted to find new methods in which fungi and bacteria were used in the biological control against pests. Totally 10 bacterial strains including 2 strains of Brevibacillus brevis (CP-1, FD-1), 1 strain of Bacillus thuringiensis (FDP-1), 2 strains of Bacillus thuringiensis subsp. kenyae (FDP-8, FDP-42), 2 strains of Bacillus thuringiensis subsp. kurstakii (FDP-41, BAB-410), 1 strain of Bacillus subtilis (EK-7), 1 strain of Pseudomonas chlororaphis (NEM-28) and 1 strain of Bacillus sphaericus GC sub-group D (FD-49) and additionally 1 Beauveria bassiana (ET 10) fungus isolate were examined for their insecticidal activities in this study. The studied bio agents were tested by spraying on R. simulans nymphs and adults. B. thuringiensis subsp. kenyae, B. brevis and B. sphaericus GC subgroup D were the most effective on nymphs, whereas B. thuringiensis subsp. kurstakii, P. chlororaphi, and B. brevis were the most effective on adults. Under controlled conditions, mortality rate varied between 19.58%-42.08% in nymph applications, and between 6%-18% in adult applications.