The Control Efficiency of Plant Alcohol Extracts on the Laboratory Populations of Myzus persicae(Sulzer)and Lipaphis erysimi (Kaltenbach)

The effects of semiochemicals extracted from 63 species of plants, on peach aphid (Myzus per-sicae) and mustard aphid (Lipaphis erysimi), were studied in laboratory. The deterrent rate, reproduction deterrent index and the interferential index of population control (IIPC) was used to evaluate the efficiency of semiochemicals on population control of the two target aphids. The results showed that the extracts of 34 species of common plants have noticeable effect on both aphid populations, especially, Xanthium sibiricum Petr. Et Widd. and Syngonium podophyllum Schott. These plant extracts could be used to construct the plant pro-tectant to protect crops.

Improvement of Markov Chain Model for Occurrence Degree Prediction of Myzus persicae (Sulzer) and Its Application

For long-term prediction of occurrence degree of tobacco aphid Myzus persicae （Sulzer）, Markov chain method was used to establish prediction model for occurrence degree of tobacco aphid. With 4 levels of occurrence degree, Markov chain model was established based on the data in 1987-2004. The results indicated that the accuracy for total prediction in 2005-2007 and the back prediction in 1987-2004 reached 88.89% and 85.12%, respectively. The method is simple and feasible for long-term prediction of occurrence degree of tobacco aphid.

五种杀虫剂蘸根处理对烟蚜的防治效果

为了寻找投入低廉、简单高效的施药方式,采用盆栽试验和大田试验研究了烟苗移栽时用吡虫啉等农药蘸根处理对烟蚜[Myzus persicae(Sulzer)]的防治效果及对烟株生长发育的影响。结果表明,盆栽移栽时用吡虫啉、噻虫嗪、噻虫胺、呋虫胺、吡蚜酮蘸根处理,药后50 d内对烟蚜的防治效果均在97.84%以上;大田试验移栽时用吡虫啉等农药蘸根处理,持效期可达50 d,50 d内防效为20.41%~100.00%;移栽时用吡虫啉等农药蘸根处理,对大田烟草生长发育没有影响。5种杀虫剂可以通过蘸根的方式在烟草种植中使用。