Predation by the Cadelle Tenebroides mauritanicus (L.) (Coleoptera, Ostomidae) on Three Species of Stored-Product Insects

The rates of predation by the adults of Tenebroides mauritanicus were determined for the three stored-product pests. The average number of completely or partially eaten insects per beetle per day was -2.5-2.7 for Rhyzopertha dominica, 0.5-0.7 for Sitophilus oryzae and 0.2-0.4 for Oryzaephilus surinamensis respectively., For the latter two species the number of insects consumed on the 1st day was greater than the latter days. For the rice weevil the greater numbers of dead and partially eaten weevils were left behind than the other two species. The relative preferences for the three species were examined. R. dominica was. most and O. surinamensis least attractive to the cadelle in the preference. The per cent insects eaten in the preference increased for R. dominica and S. oryzae and decreased for O. surinamensis as compard with preying on the single species. Using S. oryzae and O. surinamensis as prey, preying on dead body was tested. Both the rates of predation increased on the dead insects. The rate of predation on the dead S. oryzae did not differ from that on the living R. dominica. The relative preferences for the three species were attributed to the differences of vagility and palatability among the prey species. It was considered that the cadelle played an important role in natural control over the stored-product pests.