Resistance of Wild Species of Arachis to the Twospotted Spider Mite, Tetranychus Urticae1,2,3

Abstract

Abstract Wild species of Arachis representing all seven sections of the genus were screened in the greenhouse for resistance to the twospotted spider mite, Tetranychus urticae Koch. Most species of the section RHIZOMATOSAE were found to be highly resistant to the mite. Plant introductions 338296, 338317, 262840, 262827 and several other members of the section RHIZOMATOSAE were virtually mite free throughout the tests. PI 276203 from section EXTRANERVOSAE, PI 262142 from section ERECTOIDES and PI 331194 from section ARACHIS also had relatively low damage ratings in this study. Section Arachis is the only section with resistance to the mite that will cross readily with cultivated peanuts, Arachis hypogaea L. Thus the utilization of germplasm resistant to the mite from the wild species will require complicated and difficult breeding procedures.