Abstract: Proreus simulas (Still) is a predatory natural enemy effective in the control of pests in reed fields. The biological characters and predation to Melanaphis sp. Of the chalisochids have been studied. The adult and third and fourth instar nymphs of the earwig hibernate on the remained reed stems and leaves, or in the soil chinks. At about (22.47+0.47)℃, the average incubation period of the eggs is 8.42 days. There are three moults or four instars in the larvae. At the laboratory temperatures, the averagedevelopment periods of the first instar, second instar, third instar and fourth instar nymphs are 8.7, 4.28, 4.03, and 10.95 days, respectively. The adults and nymphs of the chalisochids prey upon some species of insect pests occurring in reed fields, such as:Oligonychus sp. , Melanaphis sp. , Baliothrips serratus, first instar nymphs of Dimorphiters spinolae and first instar larvae of Chiloniponella. At the laboratory temperatures, the number of eggs laid per female after hibernation at the first oviposition and the second oviposition varies from 24 to 34 and from 19 to 48, respectively, while that at third oviposition varies from 24 to 34. The preying activing of the chalisochids reach-es a greatest attacking rate at 28℃. The average number of aphids eaten by an earwig in one day increases with the stadium of the larva and reaches the maximum at 4th instar, which approximates to that of an adult, the functional responses of 1-4 instar nymphsand adults are found to be Holling II type. By these investigations, the authors believe that the earwig, Proteus simulas, is a valuable predator for pest control and have put forward a proposal about the protection and utilzation of this natural enemy.

Key words: earwig, biology, predation, simulation model, protective utilization