Source : WordNet®

armyworm
     n 1: noctuid moth larvae that travel in multitudes destroying
          especially grass and grain [syn: {army worm}, {Pseudaletia
          unipuncta}]
     2: moth whose destructive larvae travel in multitudes [syn: {Pseudaletia
        unipuncta}]
     3: larva of fungus gnat; march in large companies in regular
        order