The effect of various organic matters to add to baited traps, on the number of captured rhinoceros beetles was studied under field conditions, at El-Kassassen district. Results obtained could be summarized as follows:- 1. Cattle dung The total numbers of different stages (eggs, larval, pupae and adults) in pits were increased during April, July and September and it had three peaks in seasons 1998 and 1999. 1.2. Pigeon dung The total numbers of different stages (eggs, larval, pupae and adults) in pits were increased during April, July, and September and it had three peaks in seasons 1998 and1999. 1.3. Chicken dung The total numbers of different stages (eggs, larval, pupae and adults) in pits were increased during April, July, and October and it had three peaks in seasons1998 and1999. 2.6. Preference of organic matter additions The highest counts in pits supplied with cattle dung (24163 individual) followed by pits supplied with pigeon (17862 individual) and the least recorded in chicken (2290 individual). The results can help us to recommend that the cattle dung is the most preferable organic matter addition in pits to attract or rear this pest and to monitor the level of population .