Phylogeny and evolution of pharmacophagy in tiger moths (Lepidoptera: Erebidae: Arctiinae)

• Published in: PloS one Vol. 9; no. 7; p. e101975
• Main Authors: Zaspel, Jennifer M, Weller, Susan J, Wardwell, Charles T, Zahiri, Reza, Wahlberg, Niklas
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 18.07.2014; Public Library of Science (PLoS)
• Subjects: Adults; Alkaloids; Animal reproduction; Animals; Bayesian analysis; Biodiversity; Biology and Life Sciences; Butterflies & moths; Data processing; Dehydrogenase; DNA barcoding; Ecology; Ecology and Environmental Sciences; Elongation; Evolution; Evolution, Molecular; Feeding Behavior; Females; Genetic markers; Glyceraldehyde-3-phosphate dehydrogenase; Host plants; Isocitrate dehydrogenase; Leaves; Lepidoptera - physiology; Malate; Malate dehydrogenase; Males; Mitochondria; Moths; Pharmacology; Pheromones; Phylogeny; Physiology; Plant diversity; Pyrrolizidine alkaloids; RNA; rRNA 28S; Specialization; Species; Species diversity; Statistical inference; Topology; Utetheisa ornatrix; New York; United States > US; Minnesota
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0101975

The focus of this study was to reconstruct a phylogenetic hypothesis for the moth subfamily Arctiinae (tiger moths, woolly bears) to investigate the evolution of larval and adult pharmacophagy of pyrrolizidine alkaloids (PAs) and the pathway to PA chemical specialization in Arctiinae. Pharmacophagy, collection of chemicals for non-nutritive purposes, is well documented in many species, including the model species Utetheisa ornatrix L. A total of 86 exemplar ingroup species representing tiger moth tribes and subtribes (68 genera) and nine outgroup species were selected. Ingroup species included the most species-rich generic groups to represent the diversity of host-plant associations and pharmacophagous behaviors found throughout Arctiinae. Up to nine genetic markers were sequenced: one mitochondrial (COI barcode region), one nuclear rRNA (D2 region, 28S rRNA), and seven nuclear protein-coding gene fragments: elongation factor 1-α protein, wingless, ribosomal protein subunit S5, carbamoylphosphate synthase domain regions, glyceraldehyde-3-phosphate dehydrogenase, isocitrate dehydrogenase and cytosolic malate dehydrogenase. A total of 6984 bp was obtained for most species. These data were analyzed using model-based phylogenetic methods: maximum likelihood (ML) and Bayesian inference (BI). Ancestral pharmacophagous behaviors and obligate PA associations were reconstructed using the resulting Bayes topology and Reconstructing Ancestral States in Phylogenies (RASP) software. Our results corroborate earlier studies on the evolution of adult pharmacophagous behaviors, suggesting that this behavior arose multiple times and is concentrated in the phaegopterine-euchromiine-ctenuchine clade (PEC). Our results suggest that PA specialization may have arisen early in the phylogeny of the subfamily and that facultative larval pharmacophagous behaviors are the derived condition.