Student Research Projects

Morphology of Mandible and Labial Palps of Four Invasive Scolytid Beetle Species (Xyleborus affinis, Xyleborus ferrugineus, Xyleborus onoharaensis, Xyleborinus saxeseni)

Student Mikel Conway, ‘14
Faculty Mentor(s)
Department Biology
Course BIO 400: Scanning Electron Microscopy (SEM)


Comparative studies of the microscopic structures of scolytid beetles are useful for species identification, public education and scientific research. The purpose of this study was to use SEM micrographs to document variation of the mandibles and labial palps of three invasive species scolytid beetles that originated in Asia: Xyleborus affinis, Xyleborus ferrugineus, and Xyleborinus saxeseni. This research used the Hitachi S-3400N scanning electron microscope on the campus of Virginia Wesleyan College. I observed some similarities and significant variations from the morphology exhibited in different species. The Xyleborus affinis displayed mandibles with smooth claw-like, non-dentate interior, and exterior margins having a slight overlap at mandible tips. The labial palps were visible and ventral to mandibles. The Xyleborus ferrugineus had similar mandibles to the Xyleborus affinis with smaller labial palps that were more spread apart. The Xyleborinus saxeseni displayed smooth, somewhat flattened claw-like non-dentate interior and exterior margined mandibles that were forked at mandible tips and barely overlapped. The labial palps were smaller and concealed under mandibles.