SG: Investigating a cross-kingdom convergence: The phylogeny of stick insects and the evolution of masquerade crypsis (Insecta: Phasmatodea)

Brigham Young University, Provo UT

Investigators

Abstract

Stick and leaf insects are large, tropical herbivores with an incredible ability to mimic twigs, bark, and leaves. Despite being important players in tropical ecosystems, stick insect diversity and evolution is the least understood of any large insect group. Many stick insects rely on ants to help disperse their eggs, but little is known about how this complex interaction evolved. The project will result in a greater understanding of stick insect evolution and the first, comprehensive understanding of species diversity. Because stick insects are common and diverse in the tropics, this research will provide critical baseline data for ongoing tropical conservation efforts. Four undergraduate students will gain training in all aspects of the scientific process using stick insects as a focal group. An interactive museum exhibit targeted to K-12 students will present the evolution of stick insect camouflage, ant associations, and the role these insects play in the natural world. The exhibit will also focus on conservation issues in the tropics, using the Lord Howe Stick Insect as an example of species rescue and recovery. The project will reconstruct a robust phylogeny for stick insects based on DNA sequence data, document the parallel evolution of the different stick insect body types, investigate shifts from crypsis to aposematism, and determine whether these shifts are correlated with other life history traits and species radiations. The project will decipher the evolution of stick insect oviposition techniques, determine how many times egg dispersal via ants has evolved, investigate correlates of adult dispersal ability and reliance on ant-mediated egg dispersal, and study the temporal and geographic overlap of particular plant and phasmid species. It will also provide the baseline data to understand a fascinating cross-kingdom convergence on reliance on ant-mediated egg dispersal in both stick insects and angiosperms. This project will provide the scaffolding for future taxonomic work, revisionary systematics, and studies into the evolution of their unique forms.