| As a kind of social insects, bees have important ecological function and economic value. Neonicotinoid insecticides against mainly in nicotinic acetylcholine receptor, the acetylcholine receptor on insect nervous system has good selectivity, and has the uptake, stomach poison, flight from and tag, and so on, in high efficiency of hymenoptera and coleoptera pests prevention and low toxicity to mammals. In recent years, new neonicotinoid insecticides have become the current highest sales in the process of agricultural production and usage of the fastest growing type of pesticides. However, bees and other pollinators in large-scale population collapse phenomenon (CCD, colony collapse syndrome) has attracted attention from all walks of life, though the reason is not yet clear, but the growth and development of new neonicotinoid insecticides to bees and impact on the population has been widely recognized.Based on Italian bee (Apis mellifera 1.) as the sample, by studying the new neonicotinoid insecticides to bee feeding toxicity, acute toxicity, chronic toxicity 10d larvae feeding and chronic toxicity, comprehensive evaluation in detail a few class new neonicotinoid insecticides on bee toxicity.Neonicotinoid insecticides to bees acute toxicity experiment, through the "small beaker method", "feeding tube method", "drop method" determination of 97.3%imidacloprid technical,25% imidacloprid (wettable powder,96% thiamethoxam oxazine technical,30% thiamethoxam oxazine suspending agent,7% thiamethoxam amine technical,5% wettable powder,96% thiamethoxam amine organism bug amidine technical,40% totally amidine soluble powder to bees acute toxicity (48 h LC50 or LD50). According to toxicity grading standards, totally amidine, soluble powder three methods to measure the acute toxicity of poisoning, other agents through "drop method" and "feeding tube method" two ways to measure its acute toxicity are of high poison, "small beaker method" oral toxicity is poisonous. The dangerous business value (HQ) were used to evaluate the risk of pesticides to bees to the research results show that the organism worm amidine to bees as low risk, imidacloprid, thiamethoxam, thiamethoxam amine are high risk.Neonicotinoid insecticides for bee larva chronic toxicity of 10 d feeding experiment,imidacloprid of bee larvae chronic 10 days feeding toxicity, imidacloprid dose levels of imidacloprid from 1.25?g a.i./L to 3.11?g a.i./L and LOEC of Imidacloprid on bee larvae for 3.11?g a.i./L, namely 1.08 ng ai./bee. Thiamethoxam on bee larvae chronic 10 days feeding toxicity, thiamethoxam dose levels from 2.00?g a.i./L to 4.98 ?g a.i./L, thiamethoxam to bees LOEC is 4.98?g a.i./L, namely 1.51 ng a.i./bee.Neonicotinoid insecticides on acute toxicity test of bee larvae, imidacloprid on bee larvae (72 h) LC50 value of 27.3p.g a.i./L. During the test as per larva fed 30?1 medicated food, so the LD50 (72 h) of 0.818 ng/larvae. Thiamethoxam oxazine bee larvae in acute toxicity (72 h) LC50 value is 21.3?g a.i./L, namely (72 h) LD50 value of 0.639 ng/larvae.Neonicotinoid insecticides on bee larvae in the chronic toxicity test, imidacloprid (D4-D7) during the period of the larvae fed NOEC estimate of 1.364?g a.i./L, namely 0.190 ng a.i./larvae; Pupation stage (NOEC D15) estimate of 0.682?g a.i./L,namely 0.0955 ng a.i./ larvae; Feather phase NOEC estimate of 0.682?g a.i./L, namely 0.0955. Thiamethoxam lamictal during larval feeding (D4-D7) NOEC estimate is 0.508?g a.i./L, namely 0.0711 ng a.i./larvae; Pupation rate (NOEC D15) estimate of 0.127?g a.i./L, namely 0.0178 ng a.i./ larvae; Feather rate (NOEC D22) estimate of 0.127?g a.i./L, namely 0.0178 ng a.i./larvae. |
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