Studies of caterpillar defense strategy evolution typically focus on aposematic coloration, gregarious behavior, and/or chemical defense. In the slug moth family Limacodidae, the evolution of chemical defense is coupled to the life history trait of first instar feeding behaviors. In nettle caterpillars, the first instars fast and molt into a second instar that feeds. In contrast, gelatines and monkey slug larval forms feed in the first instar. This study focused on whether the evolution of fasting associated with the nettle morphology was a derived trait of single or multiple origins. Twenty-nine species of Limacodidae (including one Chrysopolominae) representing 27 genera and four outgroup species with known first and final instar morphologies and behaviors were included. Four out-group species representing Megalopygidae (1 sp), Dalceridae (1 sp) and Aididae (2 sp) were included. These were sequenced for three molecular markers for a total of 4073 bp, mitochondrial COI (~1500 bp), 18S (~1900 bp) and the D2 region of 28S (approximately 670 bp). Maximum likelihood and Bayesian analyses were conducted. The resulting phylogeny and comparative analysis of feeding strategy revealed that the nettle caterpillar morphology and behavior of larval fasting may have a single origin.
Bibliographical noteFunding Information:
We thank reviewers and collectors who provided material. Todd Gilligan (Colorado State University) provided a review of the manuscript and Kenji Nishida (University of Costa Rica) kindly provided the images of the caterpillars he reared in Costa Rica. We thank Taylor Wardell and Peter Larson for technical support of data collection. Epstein’s research was funded by: INBio , Project ALAS, National Zoological Park (Smithsonian Institution), and CPHST (USDA). Funding for Weller was provided by the National Science Foundation’s Assembling the Tree of Life Program (0531626) and a University of Minnesota Agriculture Experiment Station Project. Zaspel’s contribution was funded by the College of Agriculture at Purdue University .
- Larval ontogeny