Lukas Humer


Comparison of the life stages of Peruphasma schultei regarding mandibles and biting tracks

MEd Student
Advisor: Harald Krenn

Unit for Integrative Zoology, Department of Evolutionary Biology
University of Vienna


Phasmatodea is a mostly tropical and subtropical taxon of hexapods. Its members are remarkable because of their big body size and spectacular look. Phasmids belong to the tallest insects of the planet and often show phytomimesis, why they are also known as stick insects, “walking stick” or “walking leaf”. They are easy to keep which makes phasmids a perfect research subject for school. One of those is Peruphasma schultei, an endemic stick insect discovered 2004 in the rainforest of Peru. It has biting-chewing mouth parts and feeds off the leaves from Schinus. The aim of this master thesis is to compare the mandibles and eating tracks of the six life stages of Peruphasma schultei. This project made use of light and scanning electron microscopy as well as video observation. Living and death individuals have been observed. Results showed that the size of mandibles is rising but the morphology of the cutting edge stays almost the same within the life stages. Regarding the eating tracks from Peruphasma schultei at leaves from Ligustrum vulgarae this survey found that those become bigger but do not change in form. Finally, the mandibles and eating tracks of Peruphasma schultei are going to be compared with those of nearer relatives like e.g. Orthoptera and other phasmids.