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 1^st and 2^nd 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 2^nd 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 3^rd 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 1^st and 2^nd instar nymphs of D. neobrevipes, and the development stage of D. neobrevipes after the 3^rd instar nymph could maintain a good survival ability at 10 ℃.