Studies On Experimental Ecologic Toxicology Of The Avermectin Series Insecticides To Diamondback Moth Plutella Xylostella L.

Avermectin series are a group one that composed both natural occurring and semisynthetic macrocyclic lactones that exhibit potent insecticidal, acaricidal, and anthelminthic activities and which have novel mode of action. Experimental ecologic toxicology of the Avermectin series insecticides was studied in laboratory measurement including different temperature, light length, lighted hour etc. The different effects of fecundity to the insect treated by sub-lethal dosage of the Avermectin series were surveyed; the experimental population life tables of the insect were built; the relationship of the mortality of the insect with the different concentration of the Avermectin series, the time lengh without illuminated by UVL, the hour illuminated by UVL and the intensity of UVL were studied in this paper.The toxicities of the Avermectin series against the experimental insect were increased as the temperature enhanced in some temperature ranges. The topical toxicity of Abamectin increased by 16 folds as the temperature changed from 16 to 31C; 19 foldss of Ivermectin when the temperature was enhanced from 16 to 31C and 10 folds with Emamectin from 16 to 31C. The most changed temperaturefollowed toxic activities of Abamectin were from 22 to 28癈;the toxicity of Ivermectin was obviousely changed from 19 to 25癈 and Emamectin had two obviousely temperature changed ranges that were: from 16 to 22癈 and 28 to 31癈. The stomachic toxicity of Abamectin increased by 30 folds as the temperature augmented from 16 to 28 "C; the Ivermectin increased by about 30 folds;that was surprised that the toxicity of Emamectin was increased by 1000 folds when temperture from 16 to 31癈. Emamectin has showed a highest stomachic toxicity and the stomachic toxicity of Emamectin has a sharp increase from 16 to 25癈.Both of the fecundity and oviposition period of the contemporary generation of diamondback moth and the secondary generation of the insect were affected by sub-lethal dosage of test insecticides. The intensity of fecundity of the contemporary generation wre affected by the compounds was ranged which were: Ivermectin>Emamectin>Abamectin; the different effects of oviposition period was followed as Ivermectin>Emamectin>Abamectin. The secondary generation's fecundity ordered as Emamectin>Abamectin> Ivermectin and the oviposition period order was Emamectin> Ivermectin>Abamectin.The effects of weightiness of diamondback moth, pupated percentage and emergence percentages of the contemporary generation of the insect were not obviously changed after treating by the sub-lethal dosage of Avermectin series. The pupated percentage was changed from 45. 23% to 50. 12%; the mean weightiness was from 4. 25mg to 4. 84mg and the pupated percentage was from 64. 21% to 67. 53% respectively. The effects of weightiness of diamondback moth and emergence percentages of secondary generation were obvious different by using different Avermectins. The affected weightiness of the insect was ranged: Abamectin>Emamectin>Ivermectin. The affected emergence percentages ordered as followed Emamectin>Iverrnectin> Abamectin. The different population parameters of diamondback moth disposed by the Avermectin series were showed as below:R0:Abamectin>Ivermectin>Emamectin; T: Ivermectin>Abamectin>Emamectin; rm:Ab,amectin>Ivermectin>Emamectin; :Abamectin>Ivermectin>Emamectin.The researches of the different of the mortality of the diamondback moth with limited the concentration of the series insecticides, the light-free hours behind disposed by the product, the length of the exposed time under ultraviolet light (UVL) and the hours without UVL was also studied used the method of rotation composition design of regress. The results showed that the mortality of the test insect was obviously affected by the concentration of Avermectin series, the light-free hours behind disposed the compouds, the illuminated UVL hours and the intensity of UVL.