| Summary: | This study examined the performance of <i>Poanes viator</i> (Edwards) (Hesperiidae), a native North American skipper, and <i>Rhizedra lutosa</i> (Hübner) (Noctuidae), an introduced moth, reared on native and non-native, invasive lineages of <i>Phragmites australis</i>. <i>Poanes viator</i> is a generalist on monocots and larvae were also fed leaves of <i>Zizania aquatica</i>, a native macrophyte that the skipper commonly uses as a host plant. Larval survival and duration, pupal weight, and pupation time were compared for <i>P. viator</i> feeding on leaf tissue and <i>R. lutosa</i> feeding on rhizomes of either native or introduced plants. We also tested an artificial diet supplemented with <i>P. australis</i> rhizome powder as a potential food for rearing other stalk and rhizome boring Lepidoptera. In experiments using excised plant tissues, some individuals of both species fed and developed to the pupal stage on native and introduced plants, but overall, larval survival rates were low. Plant species/haplotype identity did not cause strong differences in larval survival for either species. However, <i>P. viator</i> larvae only pupated when feeding on native plants (<i>Zizania aquatica</i> and native <i>P. australis</i> haplotypes), whereas <i>R. lutosa</i> successfully pupated on both native and introduced <i>P. australis</i>. Although larval survival was low, 100% of <i>P. viator</i> and 95% of <i>R. lutosa</i> that reached the pupal stage emerged as adults. <i>Rhizedra lutosa</i> larvae fed an artificial diet supplemented with <i>P. australis</i> rhizome powder had significantly greater survival and pupal weights, and shorter pupation times than larvae fed rhizomes only. Several specialist Lepidopteran species are being considered for approval as biological control agents for the non-native <i>P. australis</i> haplotype, and the convenience and increased larval performance make this artificial diet a good alternative for rearing organisms.
|
|---|