| Tetranychus acinnabarinus Boisduval is an important pest mite of agricultural crops and it is polypaphous destructive and difficult to control.Neoseiulus californicus(McGregor)belongs to the Phytoseiidae and Neoseiulus.Because of the advantages of strong predation ability to pest mites,high fecundity and strong resistance to stress,N.californicus(McGregor)is considered to be one of natural enemies with great potential for biological control.In this paper,we studied the toxicity and sublethal effect of B-azolemiteacrylic and cyflumetofen on T.cinnabarinus Boisduval and and N.californicus(McGregor).The aim of this study was to provide theoretical basis for protection of natural enemies and development of a reasonable and efficient comprehensive prevention and control strategies.The main contents and results are as follows:1.Laboratory bioassays were conducted to evaluate the toxicity of 6 acaricides against egg,larva,nymph,and female adult of T.cinnabarinus Boisduval and N.californicus(McGregor).The results showed that,after a 24h exposure,except that female adults of T.cinnabarinus Boisduval and were not susceptible to spirodiclofen and extoxazole,all acaricides including B-azolemiteacrylic,cyflumetofen,bifenazate,spirodiclofen,pyridaben and etoxazole were demonstrated a high toxicity to all stages of T,cinnabarinus Boisduval.And the toxicity changed with the type,bioassay method of acaricides and mites of treatment.B-azolemiteacrylic were the most toxic against larva,nymph and female adult among all the acaricides.LC50 value of B-azolemiteacrylic and cyflumetofen were 1.472?g/mL and 1.472?g/mL to eggs,were 0.378?g/mL and 0.863?g/mL to larva,were 0.329?g/mL and 2.172?g/mL to nymph,were 0.410?g/mL and 2.026?g/m to female adults using Slide-dip method and were 0466?g/mL and 2.683?g/mL to female adults using leaf-residue method.In addition,expect that the LC50 of pyridaben on eggs and female adults of N.californicus(McGregor)were 9.424?g/mL and 126.72?g/mL,and the LC50 of etoxazole on eggs of N.californicus(McGregor)were 4.324?g/mL,respectively,the eggs and female adults of N.californicus(McGregor)were not susceptible to all acaricides because the hatching rates were between 99.00%and 100%and survival rates of female adults were 100%to 24h,99.33%-100%to 48h,and 97.33-99.67%to 72h,respectively,when eggs or female adults were treated with recommended concentrations of the other acaricides.Also,the side effect of spirodiclofen,pyridaben and etoxazole on survival and sloughing of larva of N.californicus(McGregor).2.Based on the theory of age-stage,two-sex life table,sublethal effect of B-azolemiteacrylic and cyflumetofen on development,reproduction and population dynamics of FO and F1 generation of T.cinnabarinus Boisduval were determined through the sublethal concentrations LC10 and LC30 of the two acaricides treating eggs or young female adults.The results showed that,compared with control,the female adults treated with sublethal concentrations of B-azolemiteacrylic and cyflumetofen had a significant reduction in the Oviposition rate,fecundity-from 26.06 eggs of control to 12.53,5.40,10.42,and 4.79 eggs and longevity-from 9.14 days of control to 6.89,4.44,6.06,and 3.85 days,and a significant increase in pre-oviposition period.Compared with control,F1 generation period of all stages significantly prolonged except in the egg duration and deutonymph duration of females treated with B-azolemiteacrylic.In addition,F1 generation of all treated female adults all had a significant reduction in longevity,life span,Oviposition rate,oviposition period,and had a significant increase in pre-oviposition.And longevity,life span,oviposition period and fecundity were 11.85,23.57,8.65days and 43.55 eggs per female for control,were 8.37,20.35,5.36 days and 23.57 eggs per female for treatments of LC10 of B-azolemiteacrylic,were 7.63,19.66,4.78days and 20.8 eggs per female for treatments of LC30 of B-azolemiteacrylic,were 8.48,20.67,5.40 days and 23.04 eggs per female for treatments of LC10 of cyflumetofen,and were 7.38,19.84,4.69 days and 18.05 eggs per female for treatments of LC30 of cyflumetofen.Also,intrinsic rate of increase(rm),finite rate of increase(?)and net reproductive rate(R0)were significantly reduced and in F1 generation of treated females,and decreased significantly as sublethal concentration increased.There was no significant difference between the treatments with same concentration of the two acaricides.For control,treatments of LC10 and LC30 of B-azolemiteacrylic,treatments of LC10 and LC30 of cyflumetofen,rm were 0.209,0.166,0147,0.164,0.145,and ? were 1.232,1.180,1.158,1.178 and 1.156,and R0 were 32.74 14.96,11.02,16.02,11.52,respectively.When treating eggs with sublethal exposure of B-azolemiteacrylic and cyflumetofen,there was little influence on the development of all different stages except the eggs and juvenile.Also,there was little side effect on the longevity and life span expect in the eggs treated with cyflumetofen LC10.However,intrinsic rate of increase(rm),finite rate of increase(?)and net reproductive rate(R0)were significantly reduced in trial that the eggs were treated with sublethal dose of B-azolemiteacrylic and cyflumetofen,compared to control.3 Based on the theory of age-stage,two-sex life table,sublethal effect of B-azolemiteacrylic and cyflumetofen on development,reproduction and population dynamics of F0 and F1 generation of N.californicus(McGregor)were determined through the recommend concentration treating the eggs and young female adults of N.californicus(McGregor)directly and feeing the female adults with T.cinnabarinus Boisduval treated with LC10 and LC30 of the two acaricides.The results showed that there was little effect on the development,longevity,life span,and generation time of F1 generation of eggs or females treated with sublethal concentrations of the two acaricides,except in the development of the few stages of N.californicus(McGregor)treated with the two acarcidedes.However,not only were there a significant reduction in longevity,oviposition period,fecundity per female of F0 generation,but also there were an significant reduction in emergency rate,proportion of female,oviposition period,fecundity per female,intrinsic rate of increase(rm),finite rate of increase(?)and net reproductive rate(R0)and had a significant increase in the pre-oviposition of F1 generation of female treated with the two acaricides directly.As to control and treatments of B-azolemiteacrylic and cyflumetofen to female adults,rm of F1 generation were 0.290,0.233,0.230,and ? were 1.336,1.263,1.258,and R0 were 27.37,15.91 and 14.93,respectively.There was no significant effect on the fecundity and parameters of life table of eggs treated with the two acaricides,expect that the oviposition period of females of eggs treated with the two acaricides and fecundity,net reproductive rate(R0)of F1 generation of eggs treated with cyflumetofen were significantly decreased.As to control and treatments of B-azolemiteacrylic and cyflumetofen to eggs,rm of F0 generation were 0.292,0.277,0.269,and ? were 1.338,1.319,1.309,and R0 were 28.50,24.56,21.78,and T were 11.49,11.55 and 11.44days,respectively.When female adults were fed on T.cinnabarinus Boisduval treated with LC10 and LC30 of the two acaricides,pre-oviposition period was significantly prolonged,and longevity,oviposition period and fecundity per female were significantly reduced and changed with the concentration.The development period of all stages and immature period of N.californicus(McGregor)F1 generation of female fed on treated T.cinnabarinus Boisduval were all prolonged at varying degrees,and Longevity and life span were significantly reduced except in the F,generation of females fed on T.cinnabarinus Boisduval treated with B-azolemiteacrylic LC10.For control,treatments of LC10 and LC30 of B-azolemiteacrylic,treatments of LC10 and LC30 of cyflumetofen,longevity were 31.51,29.21,24.21,26.26and 22.89 days,and life span were 36.13,34.21,29.48,31.25 and 27.96 days,respectively.In addition,intrinsic rate of increase(rm),finite rate of increase(?)and net reproductive rate(R0)of F1 generation of female of LC30 treatment were significantly decreased,compared to control,and that of LC10 treatment was not significantly different from that of control.For control,treatments of LC10 and LC30 of B-azolemiteacrylic,treatments of LC10 and LC30 of cyflumetofen,rm were 0.289,0.278,0.243,0.275,0.247 and ? were 1.335,1.319,1.275,1.316,1.28,and R0 were 28.71,28.02,18.13,24.62,17.56,and T were 11.61,12.01,11.91,11.66 and 11.62 days,respectively.4 Sublethal effect of B-azolemiteacrylic and cyflumetofen on the functional response of N.californicus(McGregor)to all stages T.cinnabarinus Boisduval was carried out through treating N.californicus(McGregor)and T.cinnabarinus Boisduval,respectively,using a residual type method.The result showed that predator-prey reaction model was not changed but the related parameters changed with the type,concentration,method of acaricides and mites of treatment,no matter direct or indirect treatment.Compared with the control,the functional response a/Th of the egg and nymph was increased by 27.39%and 74.54%respectively when treating N.californicus(McGregor)with B-azolemiteacrylic,and the functional parameters a/Th of larva and adult decreased by 19.71%and 18.98%respectively.But,the attack rate(a)and handing time(Th)to egg,larva and nymph of N.californicus(McGregor)treated with cyflumetofen were reduced at different degrees,and that to adult was increased.a/Th of egg,larva,nymph and adult of N.californicus(McGregor)treated with cyflumetofen increased by 85.31%,34.10%,10.52%and 61.82%,respectively.After treating T.cinnabarinus Boisduval with sublethal concentrations of the two acarcide,the attack rate a to all stages of T.cinnabarinus Boisduval of N.californicus(McGregor)were increased,and the increase of adult was the largest,and the handing time Th had little difference compared to control,except in the treatment of B-azolemiteacrylic,and a/Th to all stages of T.cinnabarinus Boisduval of all treatment was increased,expect in larva. |
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