| Coniatus steveni Capiomont has 3 generations annually and the larva have four instars. Itoverwintering as adult on lacunae or crotch of the branch or in humus under the plantThe development and other biology peculiarity of Coniatus steveni (Curculionidae, Coleoptera) undera range of constant temperatures (17, 20, 24, 28 and 32℃) were studied in the laboratory. The 2 and 3instars and the prepupa are sensitivity to temperature, are the main stage. The threshhold temperatures foregg, larva, prepupa, pupa, pre-oviposition adult, and whole generation are respectively 13.48, 12.48, 10.32,13.28, 8.71 and 11.44℃. The number of degree-days for the development of each life stage is 46.52 for egg,121.52 for larva, 31.7 for prepupa, 62.17 for pupa, 186.19 for pre-ovipositional adult, and 445.78 for wholegeneration from egg to pre-ovipositional adult.Life tables of laboratory population of Coniatus steveni at five different temperatures were consfructed.It has maximal generation mortality at 17℃and has maximal generation livability at 28℃. The mortality of1st instar is higher than other stages. The mortality of the stage from prepupa to adult is zero. Both the I andRo has maximum at 24℃, and The I(27.57) is 59 times to 17℃. The rm has maximum at 32℃is 0.0520.Compare to life tables of laboratory population, the mortality of egg is higher than other stage atnaturalness is 51.46%. The I is 10.78.The damage to saltcedar plants by adults prior to oviposition was significantly higher than that bylarvae in that consumption of pre-ovipositional adults was 5.7 times as large as larvae plus dropping debriscaused by feeding accounting for 8% of total debris. The growth of tamarisks was retarded by feeding ofC. steveni and stoped when feeding larvae above 7 per 10 cm long branch.
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