| 【Objective】The effect of low temperature stress on lethality of Dysmicoccus neobrevipes Beardsley（Hemiptera: Pseudococcidae）was determined.【Method】The lethality of D. neobrevipes at different development stages under different low temperatures（0 ℃ , 4 ℃ , 10 ℃）for five different time treatments（1 h, 2 h, 4 h, 6 h, 8 h）was observed in this study, with the compared temperature of 26 ℃ as control. And the effect of low temperature stress on the mortality of D. neobrevipes was analyzed.【Result】There were significant effects on the mortalities of the 1st and 2nd instar nymphs
of D. neobrevipes under low temperature treatments of 0 ℃ , 4 ℃ and 10 ℃ , and the mortality in each treatment was more than 30%. The mortality of the 2nd instar nymph of D. neobrevipes was over 95% after being treated for 6 h and 8 h at the low temperature of 0 ℃ and 4 ℃ . There were no significant differences in the mortality of the 3rd instar nymph of D. neobrevipes after being treated for 1 h, 2 h and 4 h at 10 ℃ compared with that at 26 ℃ , with the mortality of less than 10%. For immature female adults of D. neobrevipes, there were no significant differences in the mortalities after being treated for 4 h, 6 h at 10 ℃ compared with those at 26 ℃ . For mature female adults, there were no significant differences in the mortalities of D. neobrevipes in different treatment times at 10 ℃（less than 3%）compared with those at 26 ℃ .【Conclusion】The results indicated that the low temperature stress had a significant effect on the mortality of the 1st and 2nd instar nymphs of D. neobrevipes, and the development stage of D. neobrevipes after the 3rd instar nymph could maintain a good survival ability at 10 ℃. |
