Investigatinghowcropdomesticationandearlyfarmingmediatedcropattributes,distributions,andinteractionswithantagonistsmayshedlightontoday'sagriculturalpestproblems.Cropdomesticationgenerallyinvolvedartificialselectionfortraitsdesirabletoearlyfarmers,forexample,increasedproductivityoryield,andenhancedqualities,thoughinvariablyitalteredtheinteractionsbetweencropsandinsects,andexpandedthegeographicalrangesofcrops.Thus,somestudiessuggestthatwithcropdomesticationandspread,insectpopulationsonwildcropancestorsgaverisetopestiferousinsectpopulationsoncrops.Here,weaddressedwhethertheemergenceofcornleafhopper(Dalbulusmaidis)asanagriculturalpestmaybeassociatedwithdomesticationandearlyspreadofmaize(Zeamaysmays).WeusedAFLPmarkersandmitochondrialCOIsequencestoassesspopulationgeneticstructuringandhaplotyperelationshipsamongcornleafhoppersamplesfrommaizeanditswildrelativeZeadiploperennisfrommultiplelocationsinMexicoandArgentina.Weuncoveredsevencornleafhopperhaplotypescontainedwithintwohaplogroups,onehaplogroupcontaininghaplotypesassociatedwithmaizeandtheothercontaininghaplotypesassociatedwithZ.diploperennisinamountainoushabitat.Withinthefirsthaplogroup,onehaplotypewaspredominantacrossMexicanlocations,andanotheracrossArgentineanlocations;bothwereconsideredpestiferous.Wesuggestedthatthepergencetimesofthemaize-associatedhaplogroupandofthe"pestiferous"haplotypesarecorrelatedwiththechronologyofmaizespreadfollowingitsdomestication.Overall,ourresultssupportahypothesispositingthatmaizedomesticationfavoredcornleafhoppergenotypespreadaptedforexploitingmaizesothattheybecamepestiferous,andthatwiththegeographicalexpansionofmaizefarming,cornleafhoppercolonizedZ.diploperennis,ahostexclusivetosecludedhabitatsthatservesasarefugeforarchaiccornleafhoppergenotypicpersity.B
