The Toxic Substances Extracted From Poisonous Plants, Toxicity Testing And Security Examination

The substances, toxic to insect, were extracted from 9 species of plant collected fr om Heilongjiang province using Soxhlet-extraction method.The toxicity test indicated that of all 9 species of plant, the substances extracted f rom Chelidonium majus, Radix angelica dahurica ,Pulsatillae Chinensis, Veratrum dah uricum Loes.f, Dictamnus dasycarpus Turcz and Angelica dahurica hadmuch better p otency to kill insects than others,which had a correction mortality of 76.7%,81.7%, 85. 0%,73.3%,80.0% and 60.0% to 3^rd instar larvae of Dendrolimua superans (Butler) at r oom respectively when were diluted to 20 times. The field control effectsof the extratio ns of above 4 plants diluted to 50 times were similar to those indoor.Compared to oth ers,the extractions from Chelidonium majus and Radix angelica dahuricahad stable toxic ity to more species of forest insect.These extractions also have potency to inhibit the growth of fungi diseases. Amon g them, the extractions from Chelidonium majus, Veratrum dahuricum Loes.f., Angelic adahurica and Radix angelica dahurica had better potency, with a EC₅₀ of 42.24 mg/ ml, 31.84 mg/ml, 34.93 mg/ml, 18.82 mg/ml respectively to Sphaeropsissapinea, and 47.61 mg/ml, 36.24 mg/ml, 40.18 mg/ml, 21.21 mg/ml respectively to Alternaria altern ata(Fr.)Keissler, 28.67 mg/ml, 23.58 mg/ml, 23.20 mg/ml,12.72 mg/ml respectively toCyt ospor chrysosperma ( Pers. ) Fr..Biosafety assay showed that the toxicity of the extracts from Chelidonium majus, Veratrum dahuricum Loes.f. and Radix angelica dahurica were high to Telenomus tetr atomus Thomson, while that from Angelica dahurica was almost non-detectable. The LC₅₀ of the extractions from Angelica dahurica, Veratrum dahuricum, Chelidonium maj us and Radix angelica dahurica to fish Carassiusauratus gibelio (Bloch) were 82.2356 5 mg/ml, 52.08264 mg/ml, 29.52866 mg/ml and 15.00808mg/ml respectively, showed th em were secure. A pesticide celerity apparatus was used to test the residue toxicity of these extractions. The results were all below 50%, which confirmed that there were sec ure.