James A Robertson and Dr. Michael F Whiting, Integrative Biology
The family Erotylidae (pleasing fungus beetles) currently includes 125 genera, and approximately 2,500 described species and has a worldwide distribution. There are five currently recognized subfamilies within Erotylidae: Dacninae, Megalodacninae, Eucaustinae, Tritominae, and Erotylinae. Erotylids are mycophagous, feeding on basidiomycete fungi, and exhibit a wide range of gregarious behavior. Most erotylids have a striking appearance, exhibiting bright colors including red, yellow, pink, and purple, frequently in combination with contrasting black. These colors are often arranged in zigzag, banding, or polka dot patterns. It has been suggested that the striking coloration found among erotylids is aposematic, and erotylids are consequently presumed to be involved in many mimicry complexes with other insects. However, the phylogenetic pattern of this aposematism has never been elucidated nor has it been associated with host preference. It is therefore unclear whether the origin of a specific color pattern is a result of a single evolutionary event, or if certain color patterns have evolved multiple times within Erotylidae, perhaps as a result of convergence to similar hosts. Additionally, it has yet to be determined if discrete color pattern progressions exist among these beetle lineages, such as a transition from banding to a dotted pattern.
The purpose of this research is to establish a robust phylogenetic hypothesis for Erotylidae based on molecular data. We specifically examine the placement of Languriidae relative to Erotylidae to gain insight concerning higher-level relationships within Erotylidae. Additionally, we test whether there is any phylogenetic signal in the aposematic coloration patterns observed across erotylid lineages.
DNA sequence data (18S rDNA, 28S rDNA) for 43 erotylids and 18 outgroup taxa was used to estimate phylogenetic relationships among Erotylidae. Phylogenetic analyses were performed using 100 random addition sequences with TBR branch swapping, under parsimony criteria, resulting in a single topology of length 3868. Host preference and color pattern characters were mapped out on this topology (Fig. 1).
This analysis provides the first quantitative estimate of erotylid phylogeny. These data support the paraphyly of the families Erotylidae and Languriidae and suggest that these families should be combined into a single group. They further suggest that additional nomenclatorial changes are needed within this beetle group. Our data suggest that while host specificity defines major erotylid clades, there is little phylogenetic signal in coloration patterns.
This research was presented at two international entomological meetings and was recently submitted for publication. I am truly grateful to the ORCA program for supporting me with this research. Working on this project has been an invaluable experience and has better prepared me for grad school and my professional career.