Evaluation of armyworm infestation in north Queensland sugarcane ratoon crops

Armyworm infestations of northern Queensland sugarcane ratoon crops were observed during spring 1989, and the effects of insecticide treatment assessed. In contrast, where bare soil cultivation is practiced, crop defoliation by armyworms is sporadic and mostly occurs during mid-summer. Under those conditions, insecticide treatment of a single infestation is unnecessary. Increasing yield loss is likely if successive defoliations occur, particularly during late summer (BSES, unpublished data). Armyworm infestations of northern Queensland sugarcane ratoon crops were observed during spring 1989, and the effects of insecticide treatment assessed.