RESISTANCE STABILITY OF THE SECONDARY TILLER OF CALDWELL WHEAT AFTER THE PRIMARY CULM WAS INFESTED WITH VIRULENT HESSIAN FLY (DIPTERA, CECIDOMYIIDAE) LARVAE

Secondary tiller resistance of 'Caldwell' wheat, Triticum aestivum, wi th the H-6 gene for larval resistance to Hessian fly, Mayetiola destru ctor, was maintained, after the primary culm had been previously infes ted with virulent larvae. Earlier studies showed that a primary culm i nfested initially with a virulent larva allowed subsequent normally av irulent larvae to survive on that cultivar; however, in our study the resistance of secondary tillers was maintained even though the primary culm was infested earlier with virulent Hessian fly larvae. This gene stability for resistance is important for optimizing wheat yield of t hose cultivars that possess genes resistant to the Hessian fly that ar e tillering and infested with different biotypes.