Study On Insecticidal Activity Of By-product From Bamboo Charcoal

Take the by-product of bamboo heat treatment bamboo Vinegar and bamboo tar as raw material, Culex pipiens quinquefasciatus, Aedes albopictus, aphid, spider mite, Empoasca flavescens, Plutella xylostella as the target insect, use 9% bamboo Vinegar solubility liquid (SL), 50% bamboo tar emulsifiable concentrate (EC), 60% bamboo tar EC, 60% bamboo tar Na+ SL and 80% bamboo tar K+ SL to test the insecticidal activity of bamboo tar. The toxicological safety of 60% bamboo tar Na+ SL on creatural safety was evaluated according to the standard of GB15670-1995. The results are showed as follows:1. Bamboo Vinegar SL has provided strong efficacy by repelling instead of by killing mosquitoes. Forearm skin landing test in small cage (FLT) showed that 9% bamboo Vinegar SL can provide strong protection efficacy against female mosquitoes Aedes albopictus by electric liquid vaporizers (protection was 96%) while commercial liquid insecticide was 86%. 50% bamboo tar EC, 60% bamboo tar EC, 60% bamboo tar Na+ SL and 80% bamboo tar K+ SL have the strong insecticidal activity against aphid, spider mite, Empoasca flavescens and Plutella xylostella. The descending order of activity was: aphid > spider mite > Empoasca flavescens > Plutella xylostella. Under the same dose of preparation condition, the descending order of activity was: 60% bamboo tar EC > 50% bamboo tar EC > 60% bamboo tar Na+ SL > 80% bamboo tar K+ SL.2. Field tests showed that the insecticidal activity of 50% bamboo tar EC, 60% bamboo tar EC, 60% bamboo tar Na+ SL and 80% bamboo tar K+ SL against Empoasca flavescens reached 85.56% 14 days after spraying, reached 90%. 7 days after spraying against Aphis glycines matsumura, there were no significant difference from the control group. Under the same dose of preparation condition, 3-7 days after spraying, 60% bamboo tar Na+ SL and 80% bamboo tar K+ SL against Panonychus citri, there were no significant difference from the control group. 7 days after spraying, the survival rate of Panonychus citri were 77.7% and 74.7%, respectively, which were not significantly different from the 20% Dicofol EC control values of 75.7%.3. The results of 9% bamboo Vinegar SL were tested on creatural safety showed that acute oral toxicity LD50 >5000 mg.kg-1, the result of the mouse bone marrow polychromatic erythrocytes (PCE) micronucleus test was negative. The solution showed no irritation on intact skins of rabbits, this solution belongs to actually nontoxic compounds. According to the standard of GB15670-1995, The results of 60% bamboo tar Na+ SL were tested on creatural safety, showed that acute oral toxicity LD50 was 4160 mg.kg-1 for female while >5100 mg.kg-1 for male. The acute dermal toxicity LD50 >2000 mg.kg-1 to mouse, which have the the mild stimulates to rabbit eyes and dermal sensitization rate is zero. It belongs to grade I weak sensitizing matter. It proved that 9% bamboo Vinegar SL and 60% bamboo tar Na+ SL was safe to human and animal through oral or dermal use and touch, which is worth of further research.