Abstract
Simple SummaryWe evaluated the survival and development of a native butterfly (Poanes viator) and introduced moth (Rhizedra lutosa) fed native or introduced lineages of common reed (Phragmites australis). The native butterfly feeds more generally on monocots, so some larvae were also fed wild rice (Zizania aquatica). Using R. lutosa, we also tested an artificial diet supplemented with common reed rhizome powder as a potential food for rearing stalk and rhizome boring Lepidoptera. Generally, both insect species had low larval survival on all plants used, but high pupation success once insects reached that stage. Only P. viator larvae reared on leaves from native plants pupated and completed development. Rhizedra lutosa completed all developmental stages on native and introduced P. australis rhizomes. The artificial diet resulted in a doubling of survival and successful development to adults for R. lutosa. Several specialist Lepidopteran species are being considered for approval as biological control agents for the non-native, invasive common reed in North America, and the convenience and increased larval performance make this artificial diet a good alternative for rearing organisms.This study examined the performance of Poanes viator (Edwards) (Hesperiidae), a native North American skipper, and Rhizedra lutosa (Hübner) (Noctuidae), an introduced moth, reared on native and non-native, invasive lineages of Phragmites australis. Poanes viator is a generalist on monocots and larvae were also fed leaves of Zizania aquatica, a native macrophyte that the skipper commonly uses as a host plant. Larval survival and duration, pupal weight, and pupation time were compared for P. viator feeding on leaf tissue and R. lutosa feeding on rhizomes of either native or introduced plants. We also tested an artificial diet supplemented with P. australis 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, P. viator larvae only pupated when feeding on native plants (Zizania aquatica and native P. australis haplotypes), whereas R. lutosa successfully pupated on both native and introduced P. australis. Although larval survival was low, 100% of P. viator and 95% of R. lutosa that reached the pupal stage emerged as adults. Rhizedra lutosa larvae fed an artificial diet supplemented with P. australis 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 P. australis haplotype, and the convenience and increased larval performance make this artificial diet a good alternative for rearing organisms.
Highlights
Phragmites australis (Cav.) is a large wetland grass with a worldwide distribution
There was no significant difference in survivorship curves of larvae feed native or introduced plants (W = 0.48, d.f. = 1, p = 0.491; Figure 1), or at the plant haplotype/species level
There was no significant difference in survivorship curves between larvae fed native or introduced P. australis rhizomes
Summary
Phragmites australis (Cav.) (common reed) is a large wetland grass with a worldwide distribution. A European P. australis haplotype was introduced to the east coast of the United States in the late 1800s and continues to spread aggressively in freshwater and salt marsh ecosystems across North America [1,2]. Efforts are underway to develop biological control using European insects to target the introduced lineage, both to reduce its impacts to wetland ecosystems and protect the sympatric native subspecies [5,6,7]. Over 30 insect species are documented to feed to varying degrees on native and introduced P. australis lineages [7], and there is emerging evidence that differences in the nutritional quality and defensive traits of native and introduced haplotypes can drive the structuring of these insect communities [10,11]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.