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Controlling insecticide resistant clones of the aphid, Myzus persicae , using the entomopathogenic fungus Akanthomyces muscarius : fitness cost of resistance under pathogen challenge
Author(s) -
Erdos Zoltan,
Chandler David,
Bass Chris,
Raymond Ben
Publication year - 2021
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.6571
Subject(s) - myzus persicae , biology , aphid , pathogen , biological pest control , pest analysis , integrated pest management , pest control , entomopathogenic fungus , pesticide resistance , biopesticide , fungus , microbiology and biotechnology , botany , pesticide , agronomy , beauveria bassiana
BACKGROUND Biological control is a cornerstone of integrated pest management and could also play a key role in managing the evolution of insecticide resistance. Ecological theory predicts that the fitness cost of insecticide resistance can be increased under exposure to invertebrate natural enemies or pathogens, and can therefore increase the value of integrating biological control into pest management. In this study of the peach potato aphid, Myzus persicae , we aimed to identify whether insecticide resistance affected fitness and vulnerability of different aphid clones to the entomopathogenic fungus Akanthomyces muscarius . RESULTS Insecticide resistant clones were found to be slightly less susceptible to the pathogen than susceptible clones. However, this pattern could also be explained by the influence of length of laboratory culture, which was longer in susceptible clones and was positively correlated with susceptibility to fungi. Furthermore, resistance status did not affect aphid development time or intrinsic rate of increase of aphids. Finally, in a cage trial the application of fungus did not increase the competitive fitness of insecticide resistant clone ‘O’. CONCLUSION We found no fitness cost in reproductive rate or pathogen susceptibility associated with chemical resistance in M. persicae . In contrast, some susceptible clones, particularly those subject to decades of laboratory rearing, showed enhanced susceptibility to a fungal pathogen, but not reduced reproductive fitness, an observation consistent with down‐regulation of costly immune functions in culture. Overall, fungal pathogen control is compatible with insecticides and should not increase the selection pressure for resistance of M. persicae to chemical insecticides.