Susceptibility of Oriental fruit moth, (Grapholita molesta (Busck)) to selected insecticides and mixtures

Bioassays;Insecticide resistance;Chlorantraniliprole;Spinetoram;Spinosad;Acetamiprid;Thiamethoxam;Esfenvalerate;Lambda-cyhalothrin;Novaluron;Resistance monitoring

Jones, Moneen M.

关键词: Bioassays;    Insecticide resistance;    Chlorantraniliprole;    Spinetoram;    Spinosad;    Acetamiprid;    Thiamethoxam;    Esfenvalerate;    Lambda-cyhalothrin;    Novaluron;    Resistance monitoring;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/16855/1_Jones_Moneen.pdf?sequence=3&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

A series of experiments assessed the susceptibility of Oriental fruit moth, Grapholitamolesta (Busck) (Lepidoptera: Tortricidae), to selected insecticides and mixtures. Twopopulations – a laboratory colony from Rutgers University and a colony established in 2007 fromorchards in Calhoun County, Illinois – were tested. Both colonies were reared concurrently onlima bean diet and ‘Gala’ apples to reduce the likelihood that either colony would be lost todiseases or other factors. Bioassays were analyzed separately for each colony and for progeny ofparents reared on each food source.To determine the baseline susceptibility of G. molesta to chlorantraniliprole, spinetoram,spinosad, acetamiprid, thiamethoxam, esfenvalerate, and lambda-cyhalothrin, neonates wereplaced on wheat germ diet containing a range of concentrations of each insecticide. Overall, thetwo colonies responded similarly to these insecticides, regardless of parental food source.Results of these bioassays provide baseline data for future monitoring of of resistance.To develop and test a diagnostic dose for estimation of pyrethroid resistance in the field,the dose-mortality relationship was described for esfenvalerate applied topically to adult males.A range of concentrations was applied in 1 μl of acetone to male moths from the Rutgers colony,and the LD99 was estimated to be 0.022 μg per moth. Application of 0.022 μg esfenvalerate permoth to ca. 600 male moths from two putatively susceptible populations resulted in meansurvivorship approximately equal to the expected level of 1.0%. Application of this dose to ca.375 moths captured in two Calhoun County orchards with histories of pyrethroid use resulted inmean survivorship of 9.4% and 82%. It is proposed that 0.022 μg of esfenvalerate in 1 μl ofacetone be used as a diagnostic dose for monitoring pyrethroid resistance.iiiThe toxicities of three mixtures of insecticides to neonates were estimated.Chlorantraniliprole was mixed with acetamiprid, esfenvalerate, or thiamethoxam. Theseinsecticides may be mixed or rotated to provide broad spectrum control of orchard pests.Mixtures of chlorantraniliprole with acetamiprid or thiamethoxam did not exhibit consistentsynergism or antagonism. For chlorantraniliprole plus esfenvalerate, mortality was less thanexpected at nearly all concentrations for both colonies, suggesting antagonism despite differentmodes of action for the two compounds. The effectiveness of one or both insecticides toOriental fruit moth might be reduced if they are combined in field applications.To estimate the toxicity of novaluron, an insect growth regulator, to eggs of the twocolonies, eggs on waxed paper were dipped into a range of concentrations. Eggs from theCalhoun colony were more tolerant to novaluron than eggs from the Rutgers colony. Differencesin the responses of these colonies may represent natural variation among populations or may bethe result of selection by other insecticides used in orchards in Calhoun County before larvaewere collected to establish this colony.