EVOLUTION OF WING PATTERN AND MIMICRY IN NEOTROPICAL TIGER MOTHS

1. A B Figure 5. Phallus. A- Viviennea superba. B- Spiked projection, speckled vesica of Viviennea zonana. Crystal Boyd. Figure 1. Viviennea dolens. Greg Setliff. Figure 4. Viviennea flavicincta. Greg Setliff. EVOLUTION OF WING PATTERN AND MIMICRY IN NEOTROPICAL TIGER MOTHS Crystal Boyd (Dr. Susan J. Weller)Department of Entomology, University of Minnesota INTRODUCTION The brightly colored tiger moths (Lepidoptera: Arctiidae) comprise a large family with a world-wide distribution. In 1975, Allan Watson revised the large genus Automolis Hübner. His phenetic (overall similarity) approachcreated 11 new genera and moved the remaining species to one of 24 additional genera. The lack of phylogenetic support renders his reconfiguration uncertain since the monophyly of some genera is questionable. The evolution of wing pattern is unclear among Automolis, and varies within the genus Viviennea Watson. Some species have spotted wings and some species have transversely banded wings, with the bands being parallel or orthogonal (Fig. 2). The first hypothesis is that the transversely banded wing pattern arose once and is shared by all descendents. The alternative hypothesis is that the transversely banded wing pattern arose multiple times. • RESULTS AND CONCLUSIONS • Two equally parsimonious trees were recovered (MPT, Fig. 3). Outgroup jackknifing did not affect tree topology and the ingroup, Viviennea, was always recovered as monophyletic. • Two characters support Viviennea’s monophyly and justify its separation from Ormetica contraria, Ormetica rosenbergi, and Ormetica metallica. • Wing patterns were conserved. Each clade of Viviennea contained its unique pattern: parallel transverse bands, spots, and orthogonal transverse bands (Fig. 3). • V. flavicincta and V. dolens are conspecific based on male genitalia. They differ in wing and thoracic coloration (Figs. 1, 4). The distribution of these morphs overlaps in Brazil (ref 7). ardesiaca Viviennea griseonitens Ormetica contraria Viviennea Ormetica rosenbergi Viviennea superba Viviennea flavicincta Ormetica metallica Viviennea zonana Viviennea tegyra Viviennea moma Viviennea salma Viviennea dolens 1 3 2 2 1 7 1 Parallel Transverse Bands Spots • FUTURE DIRECTIONS • Include characters from female genitalia • Include characters from head, thorax, abdomen, and wing venation of both genders Orthogonal Transverse Bands 5 #s Bremer Support Figure 3. Strict Consensus. Strict Consensus of 2 MPT. Tree length = 67, Consistency Index = .731, Retention Index = .839.Crystal Boyd. METHODS I dissected and examined the morphology of one male for each species available (9 of 12 described) (ref. 1). Three species of Ormetica were used as outgroups. A total of 12 species were included in the analysis. Using an Olympus dissecting microscope, wing venation and structures of the head, thorax, legs, abdominal sclerites, and genitalia were examined. Dissections were recorded in a dissection notebook and databased in XCEL. Diagnostic characters were illustrated using camera lucida sketches. These sketches were scanned and inked in Adobe Illustrator for MacOS10 (Fig. 5) (ref. 2). Thirty-four characters were described (83 states) and scored in MacClade. Of the 34 characters, 21 were binary and 13 were multi-state. These were treated as unordered (non-additive). The matrix was analyzed using maximum parsimony with the computer program PAUP (refs. 3, 4). Bremer support (decay indices) were calculated (ref. 5). Outgroup jackknifing (ref. 6) was performed. Spots Parallel Transverse Bands Orthogonal Transverse Bands Figure 2. Wing pattern variation. Left to Right: Viviennea moma, Viviennea superba, and Viviennea griseonitens, respectively showing parallel transverse bands, bands reducedto spots, and orthogonal transverse bands. Crystal Boyd. REFERENCES 1. Winter Jr., W.D. 2000. Basic techniques for observing and studying moths and butterflies. Memoirs of the Lepidopterists’ SocietyNo. 5. 444 pages. 2. Larson, P., M. DaCosta, J. Donahue, & S. Weller. in prep. Phylogeny of the Milkweed tussocks and related tiger moth genera (Arctiidae: Arctiinae: Phaegopterini). 3. Maddison, W.P. & D.R. Maddison. 2000. MacClade: version 4.0 PPC. Sinauer, Sunderland. 4. Swofford, D. 2000. PAUP*-Phylogenetic analysis using parsimony. Version (Version 4.0)Sinauer, Sunderland, Massachusetts. 5. Bremer, K. 1988. The limits of amino acid sequence data in angiosperm phylogenetic reconstruction. Evolution 42: 759-803. 6. Weller, S. and and M. DaCosta. 7. Watson, A. 1975. A reclassification of the Arctiidae and Ctenuchidae formerly placed in the Thyretid genus Automolis Hubner (lepidoptera). Bulleting of the British Museum (Natural History) Entomology Supplement 25: 1-104. ACKNOWLEDGEMENTS Dr. Susan Weller, Department of Entomology, University of Minnesota-Twin Cities Michelle DaCosta, Ralph Holzenthal , and Phil Clausen Carrie Olson Larren and Carro Boyd Collections: University of Minnesota-St. Paul Grant Support: Undergraduate Research Opportunities Program at the University of Minnesota-Twin Cites, National Science Foundation • OBJECTIVES • Define characters that support splitting the genus Automolis into smaller genera, such as Viviennea • Clarify species relationships within Viviennea • Test hypotheses of wing pattern evolution