Wing surface in the damselfly Mecistogaster ornata (Zygoptera, Pseudostigmatidae): interactions between nanoscale wax and sticky spider webs alt-text


Abstract

The representatives of the damselfly family Pseudostigmatidae are known for their ability to catch small orb web spiders, or in some cases small kleptoparasitic spiders in the webs of other spiders. In this paper, I demonstrate that the nanoscopic crystalline wax coverage of wings in the pseudostigmatid damselfly Mecistogaster ornata is partially altered due to the presence of fluid-contaminated spots corresponding in their shapes and distribution to the typical beads-on-a-string (BOAS) geometry of sticky threads of orb web spiders. The spider fluid has the ability to wet superhydrophobic crystalline wax coverage. Also residues of the sticky threads were revealed in high quantities on the wing surface. The data suggest that the pseudostigmatid damselflies, due to their specific prey capturing method, have some costs and risks of being trapped by the sticky spider webs. However, high resolution SEM images revealed that the crystalline wax coverage of wings, in spite of its wettability by the spider glue, functions as a sacrificial anti-adhesive layer protecting the damselfly surface against spider adhesive traps.

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