A preliminary molecular phylogenetic assessment of the lichen moths (Lepidoptera: Erebidae: Arctiinae: Lithosiini) with comments on palatability and chemical sequestration

Abstract

The lichen moth tribe Lithosiini is best known for its hypothesized larval feeding behaviour, lichenivory. The larvae of some species have been found to be capable of sequestering polyphenolics, and the adults of some species are unpalatable to vertebrate predators. However, the chemical basis for the defence is unknown. Here we reconstruct a phylogenetic hypothesis using likelihood methods (maximum likelihood, Bayesian inference) for 65 species of Lithosiini representing 37 genera and seven outgroup species using 2806 bp of sequence data obtained from two mitochondrial gene fragments (COI barcoding region, CytB), and two nuclear gene fragments (RpS5 and ribosomal gene region 28S). Lithosiine species representing four of the seven subtribes and unplaced taxa are included in the analysis. The deeper relationships within the tribe are not strongly supported, and the monophyly of three of the four subtribes is not supported. The placement of the fourth subtribe, Acsalina, is weakly supported. We also conduct a survey of the secondary metabolites present within adults of five species. The species are examined for the presence of lichen polyphenolics and plant secondary metabolites sequestered by arctiines. Seven lichen polyphenolics are identified in the taxa examined, but no plant secondary metabolites are found using either analytical method. The results of this study and prior reports in the literature of chemical sequestration and unpalatability are plotted onto the resulting Bayesian inference phylogeny to examine the evolution of chemical defence within Lithosiini. Species that sequester lichen polyphenolics and unpalatable species occur in each of the major clades recovered in the analysis.

Systematics and origin of moths in the subfamily Arctiinae (Lepidoptera, Erebidae) in the Neotropical region

“…The results for the tribe Lithosiini differed from the phylogeny of Scott et al . () and were very similar to those of Zaspel et al . ().…”

“…Five Lithosiini clades were highly supported: two small groups with three and two genera each, here called Group 1 and Group 2, and three of the seven subtribes proposed by Bendib & Minet (), and recovered with low branch support by Scott et al . (). Two of the three species included in Group 1 ( Clemensia marmorata and Pronola magniplaga ) were previously assigned to Cisthenina by Bendib & Minet (), and one species ( Garudinia simulana ), to our knowledge, has never been assigned to any subtribe.…”

“…Two recent molecular studies resulted in valuable insights into the evolution of the Arctiinae. In the first molecular phylogenetic study of the tribe Lithosiini, Scott et al (2013) found that four of the seven subtribes proposed by Bendib & Minet (1999) based on morphological information could be recovered, although three of them had low branch support. The most in-depth study and the only molecular phylogeny of the whole Arctiinae to date (Zaspel et al 2014) corresponded largely to that of Jacobson & Weller (2002), recovering the monophyly of the tribes, although neither phylogeny could completely resolve the relationships between subtribes.…”

“…In the first molecular phylogenetic study of the tribe Lithosiini, Scott et al . () found that four of the seven subtribes proposed by Bendib & Minet () based on morphological information could be recovered, although three of them had low branch support. The most in‐depth study and the only molecular phylogeny of the whole Arctiinae to date (Zaspel et al .…”

A new species of Hypoprepia from the mountains of central Arizona (Lepidoptera, Erebidae, Arctiinae, Lithosiini)

“…Lampyrids are known to be chemically protected and distasteful to birds, but unlike most familiar nocturnal fireflies, Ellychnia lacks an abdominal light and is primarily diurnal. Research on sequestration of lichen polyphenolic compounds by other lithosiine arctiids (Hesbacher et al 1995, Conner 2009, Scott et al 2014) suggests that H.lampyroides itself has some chemical protection, thus the mimicry between these organisms is likely Mullerian. H.inculta is also likely part of this mimicry ring, although with its smaller size, dull pink markings, and grey wing color, it is a much less dramatic match to Ellychnia than H.lampyroides .…”