Triticale cultivars and seeding rates affect wheat stem sawfly survivorship and parasitism by Bracon cephi

Abstract

Several insects, including the wheat stem sawfly ( Cephus cinctus Norton, Hymenoptera: Cephidae), interfere with biomass and grain production of triticale (× Triticosecale). We conducted a 2-year study in southern Alberta to compare the cultivars Pronghorn and AC Ultima at 200 and 400 seeds/m2 in terms of wheat stem sawfly damage and incidence of a parasitoid wasp ( Bracon cephi Gahan, Hymenoptera: Braconidae). Plants of AC Ultima seeded at the high rate were on average less damaged than those of Pronghorn, and had more parasitoids. AC Ultima was characterized by more solid pith development in the lumen, compared with Pronghorn, and it can be considered adequate germplasm for the development of more resistant solid triticale cultivars.