At Tamworth, we have been monitoring H. armigera for carbamate resistance [thiodicarb (Larvin) and methomyl (Lannate, Nudrin) resistance since 1982. Thiodicarb resistance was first diagnosed in H. armigera in early 1993. The resistant populations were found in intensively sprayed sweet corn in NSW and Queensland and were associated with heavy methornyl and thiodicarb use. The thiodicarb/methomyl resistance on H. armigera remained largely confined to the sweet corn populations, until the 1994/95 summer season, when numbers of resistant individuals were found on cotton, with some control problems. In 1995/96, the problem has been exacerbated with increasing resistance frequencies and a number of resistance associated field failures.