Biology, Ecology And Control Effect Of Insecticides On Myzus Persicae In Heilongjiang Province

Myzus persicae, known as one of the major pests of tobacco, suck the tobacco which formsdry macular and spread virus disease of tobacco. It inhibits the growth of tobacco, and affects theoutput and quality of tobacco. Myzus persicae had an increasing injury of tobaccoin Heilongjiang tobacco field. It is important to control Myzus persicae. In this study, we made asystemic field investigation and indoor tests of Myzus persicae in Heilongjiang tobacco fields.We investigated the injury of Myzus persicae, population diversity of Myzus persicae in differentgeographical tobacco areas and harmless control of Myzus persicae in terms of biology andecology. Then we found the way in which temperature influenced the growth of Myzus persicaeand difference between Myzus persicae populations in different geographical tobacco areas inHeilongjiang by indoor toxicity tests and field control. This study provided theoretical basis forcontinuous, safet and effective control of Myzus persicae. The main results are as follows.1. Myzus persicae’s biology and investigation of occurrence dynamics in fieldIn Daqing, Myzus persicae overwinters in form of eggs in the rosaceae plants such as Rosadavurica, plums and apricots. In mid-April of the following year they hatch in plants where theyspent their winter. In early May they begin to migrate to the tobacco field. The peak period ofalatae’s migration occurrsd in mid-June, and in mid-July, wingless aphid’s migration peakoccurred. Alatae began to move out of tobacco field in mid to late August.2. The experimental population life tableMyzus persicae normally completed their development at15℃,20℃,25℃and30℃. Thepopulation index was greater than1except the15℃group, showing an increasing population ofthe next generation and the population multiples. But when it came to35℃, Myszus persicaeonly completed1old growth and could not be able to survive, survival rate and fecundity ofaphids increased along with the temperature increased. Survival rate reached the maximum valueat the optimal temperature. As the temperature increased continually, the survival rate began todecrease. The optimum temperature for the growth and development of tobacco aphid was25℃.3. Analysis of population diversity in different geographical tobacco areas in HeilongjiangWe analysis the gene sequences of Myzus persicae from five areas in Heilongjiang. The results showed that base contents were different but the difference was slight. By conducting aphylogeny tree, we found that NADH1gene could not distinguish the different sources ofgeographical Myzus persicae population. Further researches will be to know whether aphidspopulation differed in different geographical tobacco areas.4. Indoor toxicity tests and field controlAccording to the indoor toxicity tests and field control tests,70%imidacloprid wettablepowder,25%thiamethoxam water disperse granules,10%Paichongding suspending agent,5%acetamiprid suspending agent and2%avermectins wettable powder could control aphidseffectively. Of all these pesticides, imidacloprid and thiamethoxam achieved96%higher controleffect than the others, and the effect was stable andpersistant.5. Sensitivity of Imidacloprid on Myzus persicae in different tobacco regions ofHeilongjiangDetermination of the sensitivity on Myzus persicae showed toxicity of imidacloprid toMyzus persicae from different regions was not the same, and the difference was significant. Thesensitivity of imidacloprid on Myzus persicae from different regions was different.