Survey Instruction Details:
Baerman funnels and flasks/shakers have been used for nematode emergence/ extraction from the wheat galls in water. The seeds can also be directly dissected to release nematodes into water. Any nematodes that emerge from seed will need to be confirmed using morphological/ molecular methods.
Note: It is possible that surveys for Anguina tritici could occur in conjunction with surveys for karnal bunt in wheat.
Ectoparasitic feeding of A. tritici may cause leaf rolling, curling, and spiraling (Anwar et al., 2001). Severe infection of young plants can result in stunted plants with distorted, misshapen stems and leaves (Bridge and Starr, 2007). The ear or inflorescence may be absent or, when present, wider and shorter (Bridge and Starr, 2007). Plants mature more slowly, and produce smaller seed heads. Yield depressions of 50% are common (Ferris, 2013). Infected wheat heads are reduced with glumes protruding at an abnormal angle exposing the galls to view. This does not occur in rye heads (Ferris, 2013).
Infected seeds are transformed into galls that are light brown to nearly black in color. Galls contain a white powdery mass that consists of dry nematodes in an anhydrobiotic state (Bridge and Starr, 2007). Galls appear darker, shorter, and thicker than seed kernels. Young galls are short-thick, smooth, light to dark green, turning brown to black with age, 3.5 - 4.5 mm long and 2 - 3 mm wide. Rye galls are small, buff-colored and longer than wide, 2 - 4.5 mm long by 1 - 2.5 mm wide (Leukel, 1924; Byars, 1920).