Sublethal Effect Of Dinotefuran And Sulfoxaflor On The Mirid Bug Apolygus Lucorum (Meyer-d�r)

Apolygus lucorum Meyer-D�r is outbreaking in farmland of China recently,and seriously damages fruits,tea and cotton,resulting abscission of squares and serious losses in host corp production.At present,neonicotinoid insecticides are widely used to control sucking pests.With appearance of the 3^rd generation of neonicotinoid insecticides,it is necessary to assess the effect of A.lucorum.In this study,we compared the lethal effect of 5 neonicotinoid insecticides against 3-instar nymphs of A.lucorum in laboratory.We mainly examined the sublethal effects of dinotefuran and sulfoxaflor on the A.lucorum development,reproduction,feeding behavior and variation of 3 principal enzymes with two sublethal concentrations LC₁₀and LC₃₀.The purpose of this research to provide a scientific basis for evaluation,rational use of insecticides and the coordination between chemical and biological prevention and control.The results are as follows:The acute toxicity of 5 insecticides on A.lucorum of 3-instar nymphs showed that sulfoxaflor had the highest toxicity and LC₅₀ value was 31.57 mg/L.The next were nitenpyram,dinotefuran,acetamiprid,thiamethoxam and their LC₅₀ values were 125.77 mg/L,172.20 mg/L,182.29 mg/L,241.46 mg/L respectively.The LC₁₀0 and LC₃₀0 of dinotefuran were14.72 mg/L,62.95 mg/L and the LC₁₀0 and LC₃₀0 of sulfoxaflor were 1.23 mg/L,8.37 mg/L respectively.The dinotefuran of LC₁₀ and LC₃₀ could significantly increased the development period of 3^rd instar to eclosion for A.lucorum F₀ generation.The oviposition duration and egg hatching rate of F₀ generation exposed LC₃₀0 were significantly increased,so the effect of stimulus was obvious.The egg duration and pre-adult duration of A.lucorum F₁ generation exposed LC₁₀ and LC₃₀0 of dinotefuran were significantly decreased.The oviposition period and fecundity exposed LC₃₀0 were decreased.The dinotefuran of LC₃₀ for the fecundity of F₁generation was decreased.In EPG assays,the probing,inserting,laniating,feeding behavior of A.lucorum exposed LC₁₀ and LC₃₀ of dinotefuran had not significantly effect.The dinotefuran exposed LC₁₀ and LC₃₀ for AChE enzyme activities had not significantly different at the time of 24 h and 48 h.The GST and Car E activities of dinotefuran exposed LC₃₀ was significantly stimulated at the time of 24 h.The GST and CarE enzyme activities of dinotefuran exposed LC₁₀0 were significantly stimulated at the time of 48 h.The sulfoxaflor exposed LC₁₀ and LC₃₀ could significantly increased the development duration of 3^rd instar to eclosion for A.lucorum F₀ generation.The pre-oviposition exposed LC₁₀ was increased,but fecundity was significantly decreased,so the effect of inhibition was obvious.The egg duration and pre-adult duration of A.lucorum F₁ generation exposed LC₁₀were increased.The female longevity,oviposition and mean generation time exposed LC₃₀0 of sulfoxaflor were decreased,but male longevity and egg hatching rate were increased.The sulfoxaflor of LC₃₀ for the fecundity of F₁ generation was decreased.In EPG assays,the sulfoxaflor of LC₃₀0 increased the duration of feeding behavior.The AChE and GST enzyme of sulfoxaflor exposed LC₃₀ and the CarE enzyme exposed LC₁₀0 were significantly stimulated at the time of 24 h.The AChE activity of sulfoxaflor exposed LC₁₀0 and LC₃₀ had no obvious effect,but CarE enzyme was inhibited,GST enzyme activity exposed LC₃₀0 was significantly stimulated at the time of 48 h.