RESEARCH ARTICLE Long Frontal Projections Help Battus philenor (Lepidoptera: Papilionidae) Larvae Find Host Plants Ikuo Kandori1*, Kazuko Tsuchihara2, Taichi A. Suzuki3, Tomoyuki Yokoi4, Daniel R. Papaj5 1 Laboratory of Entomology, Faculty of Agriculture, Kinki University, Nara, Japan, 2 Forestry and Forest Products Research Institute, Tsukuba, Japan, 3 Department of Integrative Biology, University of California, Berkeley, United States of America, 4 Laboratory of Conservation Ecology, Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan, 5 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, United States of America *
[email protected] Abstract Animals sometimes develop conspicuous projections on or near their heads as, e.g., weap- onry, burrowing or digging tools, and probes to search for resources. The frontal projections that insects generally use to locate and assess resources are segmented appendages, including antennae, maxillary palps, and labial palps. There is no evidence to date that OPEN ACCESS arthropods, including insects, use projections other than true segmental appendages to locate food. In this regard, it is noteworthy that some butterfly larvae possess a pair of long Citation: Kandori I, Tsuchihara K, Suzuki TA, Yokoi T, Papaj DR (2015) Long Frontal Projections Help antenna-like projections on or near their heads. To date, the function of these projections Battus philenor (Lepidoptera: Papilionidae) Larvae has not been established. Larvae of pipevine swallowtail butterflies Battus philenor (Papilio- Find Host Plants. PLoS ONE 10(7): e0131596. nidae) have a pair of long frontal fleshy projections that, like insect antennae generally, can doi:10.1371/journal.pone.0131596 be actively moved.