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Sublethal Effect Of Three Insecticides On Drosophila Suzuki And Drosophila Melanogaster

Posted on:2018-11-07Degree:MasterType:Thesis
Country:ChinaCandidate:S G LaiFull Text:PDF
GTID:2323330515950776Subject:Agricultural Entomology and Pest Control
Abstract/Summary:PDF Full Text Request
Drosophila suzuki and D.melanogaster are the main species of fruit flies attacking cherries and other fruits.They are very difficult to be controlled and eradicated due to their short generation time,high reproductive capacity and a wide range of fruit hosts.To understand clearly the effects of sublethal dosages of some insecticides on the experimental population parameters and detoxifying enzymes of D.melanogaster and D.suzukii,and to clarify the relationship between the development,reproduction of two species fruit flies and sublethal dosages,D.melanogaste and D.suzukii were treated by different sublethal concentrations of emamectin,spinetoram and beta-cyfluthrinon,respectively.The main results are as follows:The toxicity of five insecticides to D.suzukii adults decreased in an order of beta-cyfluthrin > spinetoram > emamectin > chlorantraniliprole > avermectins,the LC50 were1.292 mg/L,1.420 mg/L,3.934 mg/L,22.926 mg/L and 155.707 mg/L,respectively;for D.melanogaste adults,the toxicity size order is spinetoram > emamectin > beta-cyfluthrin >chlorantraniliprole > avermectins,the LC50 were 2.277 mg/L,7.227 mg/L,63.74 mg/L,148.795 mg/L and 441.104 mg/L,respectively.The LC20 of emamectin,spinetoram and beta-cyfluthrin on D.suzukii were 1.68 mg/L,0.92 mg/L and 0.47 mg/L,LC10 were 1.08mg/L,0.74 mg/L and 0.27 mg/L,LC5 were 0.75 mg/L,0.61 mg/L and 0.18 mg/L;the LC20 on D.melanogaster were 2.60 mg/L,1.02 mg/L and 33.27 mg/L,LC10 were 1.52 mg/L,0.67mg/L and 23.68 mg/L,LC5 were 0.98 mg/L,0.47 mg/L and 17.88mg/L.The fecundity and longevity of D.suzuki and D.melanogaster adults were significantly affected by sublethal doses of emamectin,spinetoram and beta-cypermethrin,e.g.,the longevity of F0 generation was significantly shortened,the fecundity was significantly reduced,and the fecundity and longevity of two fruit flies treated by LC20 of three insecticides were significantly lower than those of treated by LC5 and the control,and the sublethal doses of LC20 emamectin can lead to sterility of two species fruit flies,resulting in the absence of the next generation in this study.The ecological characteristics of two species of fruit flies under three insecticides stress were analyzed by the age-stage,two-sex life tables.The results showed that the sublethal doses of three insecticides would prolong the total pre-oviposition period(TPOP)of two species fruit flies.The longevity of F1 generation was significantly shortened by emamectin,and the pupal duration of D.melanogaster was significantly prolonged under LC10 treatment;spinosad could significantly prolong larval duration and pupal duration of F1 generation D.melanogaster,while shorten the larval duration of the D.suzuki;and beta-cyfluthrin can prolong the larval duration of two species fruit flies.The mean generation time(T)of each treatment was longer than that of the control except for the treatment of emamectin,and the net reproductive rate(R0),the intrinsic rate of increase(r)and finite rate(?)under three insecticides stress were lower than that of the control.These results showed that the sublethal doses of the three insecticides had adverse effects on the fecundity of two species of fruit flies.To clarify the effects of emamectin,spinetoram and beta-cyfluthrinon with sublethal concentration on detoxification enzymes in D.melanogaster and D.suzukii,the activity of detoxification enzymes such as acetylcholin esterase(AchE),glutathione transferase(GSTs),carboxylesterase(CarE)and multifunctional oxidase(MFO)were measured.The results showed that the activity of AchE and GSTs in D.suzukii adults was activated by emamectin,while inhibited in D.melanogaster.The activity of CarE in two Drosophila speceis was activated by spinetoram and beta-cyfluthrinon.However,GSTs activity in D.melanogaster was significantly inhibited by spinetoram and beta-cyfluthrinon with the concentration of LC20.Moreover,the three insecticides with sublethal concentrations activated the activity of MFO in D.melanogaster,while inhibited that in D.suzukii.It was concluded that sublethal concentrations of insecticides could affect the activity of detoxification enzymes differently for D.melanogaster and D.suzukii.
Keywords/Search Tags:Drosophila melanogaster, Drosophila suzukii, insecticide, two-sex life table, sublethal effect, detoxifying enzymes
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