红树植物提取物的杀螨活性试验

采用叶片残毒法测定了16种红树植物甲醇提取物对柑橘红蜘蛛的杀螨活性。结果表明,海芒果、苦槛蓝、苦榔树和黄槿对柑橘红蜘蛛雌成螨的触杀活性高,药液质量浓度为10g/L时,24h的校正死亡率达90%以上;榄李、海漆和水黄皮有中等杀螨活性,校正死亡率为66.90%～74.19%;其余植物的杀螨活性低,校正死亡率在50%以下。海芒果、苦槛蓝、苦榔树、黄槿和榄李对雌成螨的致死中浓度(LC50值)分别为1.8416、2.8757、2.9218、4.9325、6.5728g/L。红树植物提取物对柑橘红蜘蛛卵也有触杀活性,其中苦槛蓝、苦榔树、木榄、海漆、老鼠簕、海芒果、白骨壤和草海桐的杀卵活性高,药液质量浓度为10g/L时,校正死亡率在80%以上。

Acaricidal Activity of Extracts from Mangrove Plants

Acaricidal activity of methanol extracts from 16 mangrove plants against Panonychus citri McGregor was determined. The results showed that the extracts from Cerbera manghas L.,Myoporum bontioides A. Gray,Clerodendrum inerme (L.) Gaertn. and Hibiscus tiliaceus L. had high contact activity against adult female mites at 10 g/L,with a corrected mortality being above 90%,extracts from Lumnitzera racemosa Willd.,Excoecaria agallocha Linn. and Pongamia pinnata (L.) Merr. had moderate acaricidal activity,with the corrected mortality being 66.90-74.19%,extracts from the other mangrove plants had low activity,with the corrected mortality being below 50%. The median lethal concentra-tions (LC50 values) of Cerbera manghas L.,Myoporum bontioides A. Gray,Clerodendrum inerme (L.) Gaertn.,Hibiscus tiliaceus L. and Lumnitzera racemosa Willd. to adult female mites were 1.8416,2.875 7,2.921 8,4.932 5 and 6.572 8 g/L,respectively. Extratcs from mangrove plants also had contact activity against eggs of Panonychus citri McGregor,and Myoporum bontioides A. Gray,Clerodendrum inerme (L.) Gaertn.,Bruguiera gymnorrhixa (Linn.) Lam.,Excoecaria agallocha Linn.,Acanthus ilicifolius Linn.,Cerbera manghas L.,Avicennia marina (Forsk.) Vierh,and Scaevola sericea Vahl had high activity against eggs at 10 g/L,with the corrected mortality being above 80%.