This project tests the accuracy of a number of assumptions about the population biology, impact, and potential control of armyworms on rice in southeast Australia.The assumptions that will be tested include: (i) that only one species (Leucania convecta) is involved; (ii) that current estimates of economic thresholds are appropriate; (iii) that methods for the selection and identification of chemical treatments are appropriate; (iv) that parasitism rates in rice may be very high; (v) that armyworm invade the crop after migration from breeding areas in western rangelands; and (vi) that only a single generation occurs within a crop due to parasitism-induced larval mortality and inadequate pupation sites in flooded crops.