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Effects On Growth, Development And Reproduction Of Pomacea Canaliculata By Three Pesticides

Posted on:2013-08-28Degree:MasterType:Thesis
Country:ChinaCandidate:D T JiaFull Text:PDF
GTID:2233330374998265Subject:Pesticides
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This paper studied effects of three pesticides (niclosamide,emamectin benzoate, tea saponin) on the growth, development and reproduction of Pomacea Canaliculata’ juveniles, youngs, primes, adults.In addition, the relationship between physiological and biochemical index and three pesticides of P. Canaliculata were studied in youngs of P. Canaliculata treated by three concentration (LC25, LC50,LC75) of three pesticides,which included crude protein,crude fat, raw sugar and activities of AChE, GSTs, Cellulolytic Enzymes.These were provideded the foundation for three pesticides’mechanism of action in P. Canaliculata,it also laid the basis for scientific and rational using molluscicide.The main results were shown as follows:1The three pesticides activity on different developmental stages of P. canaliculata. were tested. The results showed that the emamectin benzoate was the highest activity on P. canaliculata, whose the toxicity was13.07to22.5times as tea sapon’s and2.13to2.60times as niclosamide’s by the LC50of48hour compared, followed by niclosamide, but tea sapon had low activity on P. canaliculata.And their activity decreased with the increase of apple snails age.The toxicity of emamectin benzoate increased with the dipping time extension,whose the LC50were1.71mg/L,0.38mg/L,0.07mg/L after24hour,48hour,72hour respectively.2After being treated by the LC25, LC50, LC75of niclosamide, the survival rate of them decreased by10.83%to33.46%, the strongest increment inhibition rate of their body weight reached11.33%to40.44%, especially after60d being treated still maintained the stongly level of inhibition,11.81to26.18%. The growth inhibition by niclosamide was enhanced as the concentration increased.When niclosamide showed the strongest inhibition action on the growth of the snail in different developmental stages,the time was10d to50d after being treated,which was delayed with snails age increased or the concentration decreased. After the niclosamide treated, the oviposition amount had increased by32.63%to77.13%and the primes developmental duration increased10d to21d,which was delayed with the concentration increased.Morever, the eggs hatching rate of P. Canaliculata’ primes and adults were effectively decreased.3After treating the different developmental stages of P. Canaliculata by the LC25,LC50,LC75of emamectin benzoate, the survival rate of them decreased by3.75%to31.25%, the strongest increment inhibition rate of their body weight reached4.51%to64.89%, especially the strongest inhibition rate of adults was52.40%to64.89%,whose growth inhibition intensity was enhanced as the concentration increased.After10to20d being treated, emamectin benzoate showed the strongest inhibition action on the growth of them.It could not only made the oviposition amount of adults decreased,by19.64%to64.04%,but also the primes developmental duration increased10d to18d.4After treating the different developmental stages of P. Canaliculata by the LC25,LC5o,LC75of tea saponin, the survival rate of them decreased by6.25%to38.06%, the body weight increment inhibition rate reached11.69%to49.55%. After10d to40d being treated, tea saponin showed the strongest inhibition action on the growth of the snail. The juveniles and primes of the snail were always inhibited by tea saponin during test period, its inhibitory effects tended to expand as concentration of tea saponin being increased. After being treated by the high concentration LC75)of tea saponin on the youngs and primes, oviposition amount obviously decreased by19.30%to49.24%and eggs hatching rate also decreased by5.75%.5Effects of three pesticides on nutrient substance of P. Canaliculata’youngs were distinct. After being treated the youngs by low concentration (LC25) of niclosamide, the crude fat and raw sugar contents were increased by31.30%and40.54%, but the raw sugar of high treatment group(LC75)were descended by28.72%. After being treated the youngs by middle and high concentration(LC50,LC75)of emamectin benzoate, the crude protein contents were increased by7.16%to29.42%, the raw sugar of three treatment groups were increased by29.73%to64.19%,and the crude fat of high treatment groups were increased by32.11%. After being treated the youngs by low concentration of tea saponin, the crude protein contents were increased by19.82%, the crude fat of high treatment groups were increased by19.11%,and the crude fat of middle and high treatment groups were increased by54.05%to61.82%,but the raw sugar were decreased by18.24%.6Effects of three pesticides on metabolic enzymes activities of P. Canaliculata’youngs were distinct. After being treated the youngs by niclosamide, the activities’AchE of low and middle treatment groups were descended obvioussly by25.86%to38.95%, its inhibitory effects tended to decrease as concentration of niclosamide being increased,but the activities’cellulolytic enzymes were enhanced by21.19%to30.51%; the activities’GSTs of high treatment groups were increased by124.65%times,and the activities’cellulolytic enzymes were decreased by28.81%. Emamectin benzoate showed all promoter action on activities of AChE,GSTs, cellulolytic enzymes, which were enhanced by55.95%to174.01%,156.70%to376.61%,81.36%to238.98%respectively,and theirs activities tended to decrease as concentration of emamectin benzoate being increased. The middle and high of tea saponin made activities of AChE,GSTs, cellulolytic enzymes enhanced by127.97%to152.80%,363.67%to640.74%,224.58%to339.83%respectively.
Keywords/Search Tags:Pomacea Canaliculata, Growth Development andReproduction, Pesticides, Nutrient substance, Metabolic enzymesactivities
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