Four different concentrations of extracts obtained from three lichen species (Lecanora muralis (Schreb.) Rabenh., Letharia vulpina (L.) Hue, and Peltigera rufescens (Weiss) Humb) were tested against adults of Sitophilus granarius (L.) in Petri dishes. After treatments, mortalities of the adults were determined after 24, 48, and 96 h. Expectedly, higher concentration and longer exposure time resulted in higher S. granarius mortality. Mortalities 96 h after treatments with the highest concentration (20 mg/ml) of extracts of L. vulpina, P. rufescens, and L. muralis were determined as 100, 100, and 86.86%, respectively. However, there were no dead insects in the control group. Values of LC50 after 96 h for L. muralis, L. vulpina, and P. rufescens extracts were 0.666, 0.505, and 0.328 mg/ml, respectively.