Toxicities And Effects Of Four Kinds Of Essential Oils On Aphis Gossypii And Its Mail Enzyme Activities

Wolfberry is one of the most important species which growed with a large area in China.lt is always vulnerabled by a variety of diseases and insect pests since there is rich nutrition in its fruits, branches and leaves. Aphis gossypii is one of the most seriouse pests in wolfberry. It could damage leaves, buds and fruits seriously and lead to the declination of the yield of Lycium barharum L.Chemical pesticides have been used to control A.gossypii for many years with the increasing amount of drugs, but it has brought down the value of the wolfberry as the chinese herbal medicine and health product, and would caused the resistance of the aphis. In order to explore a high efficient and non-pollution control method, in this study, we explore the toxicity activities of four kinds of essential oils against A. gossypii, and effects of essential oils on enzymes activities of it. The results indicated that:1. Four kinds of essential oils have strong contact toxicity against A. gossypii, and essential oil from Ocimum basilicum was the strongest with LC50 value of 2.52ml/L, and the mortality rate was 98% when the concentration of it was 8ml/L,while the LC50 values of Agastache rugosu, Sabina vulgaris and Mentha longifolia were 2.78ml/L, 2.82ml/L and 2.86ml/L, respectively.And the mortality rate were more than 87% at the same concentration.2. Four kinds of essential oils have obvious fumigation toxicity against A. gossypii.Essential oil from O. basilicum is the best fumigation against A. gossypii with the lowest LC50 value of 0.81ml/L after fumigated 24h,and the mortality rate was 93% at the highest concentration. The LC50 value of essential oil from A. rugosus, S. vulgaris and M. longifolia were 1.28ml/L,1.36 ml/L and 1.56 ml/L, respectively,and the mortality rate were more than 76% at the same condition.3. CarE, AChE and GSTs of A. gossypii activities were obviously inhibited by four kinds of essential oils. And essential oil of O. basilicum had the strongest inhibit effect on CarE and GSTs, the value of I50 were 3.05ml/L andl.71ml/L, respectively. Essential oil of A. rugosus has the strongest inhibition effect on AChE which the I50 value of 5.64ml/L.The essential oil of S. vulgaris has obviously inhibition effect on ACP which the range of inhibition rate was 8%-48%. Essential oils from A. rugosus, O. basilicum and M. longifolia could induce the ACP activity at low concentration, but inhibited significantly at high concentration.There were not significant inhibition effect on ALP in the different concentration of both essential oils of A. rugosus and M. longifolia and the range of inhibition rate was 18%-33% and 13%-21%,respectively. Essential oils of O. basilicum and S. vulgaris would induce the ALP activity at low concentration, but inhibited at high concentration. Four kinds of essential oils induce the PO activity significantly,its activities were obviously enhanced,and it increased at the first and then decreased.