Biotype Composition of Hessian fly (Diptera: Cecidomiidae) Populations from Arkansas, Georgia, Illinois, North Carolina and Virginia

Abstract

Fourteen populations of Hessian fly, Mayetiola destructor (Say), from Arkansas, Georgia, Illinois, North Carolina, and Virginia were evaluated for biotype composition, and two Arkansas populations were tested for response to Hessian fly resistance genes or gene combinations H3, H5, H6, H7H8, and H9 to H19 in wheat. The biotype composition of Hessian fly populations was estimated by confining individual gravid females on the four wheat differential cultivars ‘Monon’ (H3), ‘Magnum’ (H5), ‘Caldwell’ (H6), and ‘Seneca’ (H7H8). The response of Arkansas fly populations to resistance genes was evaluated in replicated tests with wheat germplasm lines or cultivars homozygous for these genes. Hessian fly populations from Arkansas were predominately biotype L, with low levels of biotypes F, G, J, M, and O, depending upon population. Biotype L was predominant in the Illinois, North Carolina, and Virginia populations, although biotype D was present in populations from extreme southwestern Illinois and Virginia and North Carolina. Biotypes G, J, L, M, and O were identified from the west-central Georgia population collected at Griffin, while only biotypes M and O were identified from the southwestern Georgia population, collected at Plains. All fly populations were virulent to resistance genes H3, H5, and H6, while the southwestern Georgia population was avirulent to H7H8. Plants with single resistance genes H9 to H19 varied significantly (P ≤ 0.05) in their resistance to the two Arkansas populations. Plants with single resistance genes H9, H10, H13, H14, and H16 to H19 conditioned resistance (88 to 100%) to both populations, while plants with single genes Hll, H12, or H15 were susceptible to one or both populations. Wheat germplasm lines developed in the Purdue/USDA program that carry single gene resistances H9, H13, H14, and H16 to H19 should provide useful sources of resistance for developing improved wheat cultivars adapted to the mid-south and southeastern United States.