Diversity of order Phasmatodea: stick and leaf insects with plant associates in mountain ecosystems of Mindanao, Philippines

Abstract

There was a limited study on the stick and leaf insects in the Philippines. The Order Phasmatodea is an underclass insecta in which these species are phantoms or specters due to the majority of them being able to camouflage themselves in the environment as sticks and leaves. Their characteristics to mimic the color, size, shape, and variation of leaves and sticks make them invulnerable to be seen by their predators.  The study determined species abundance and richness of stick insects and leaf insects and their plant associates from the three selected mountain ecosystems of Mindanao, Philippines. The data that were gathered from the study provided information on the status and conservation of stick insects and leaf insects. Repeated transected walk, opportunistic method, and hand-picking were the techniques and methods that were used during the conduction of the three-day collection in the months of May and August 2022. A total of 35 individuals under four subfamilies and five species were determined, and seven plant associates were identified. The Euobrimus sp. was the most abundant species among the Order Phasmatodea. Mt. Balatukan and Mt. Sumagaya had a higher number of species richness. For the diversity index, all three sites showed a low diversity, having a result lower than 0.5 index, which meant that these species were thriving but were disturbed by manmade activities. Regarding their conservation status, the species fall under the criteria of Not Evaluated, which means further study is still needed to be conducted. Longer duration and a larger area should be considered in future studies.