Diversity of tarsal attachment structures in Mantodea (Insecta) includes two distinct attachment pad...

Praying mantises (Mantodea) are well known for their predatory behavior and striking appearance, yet surprisingly little is known about their tarsal attachment systems. Comparative studies on other polyneopteran insect clades based on large taxon samplings suggest distinct ecomorphological adaptations in the attachment systems. Detailed investigations into the micromorphology of mantis attachment pads remain scarce, although ecomorphs in Mantodea predict similar attachment pad specialisations. We studied the tarsal morphology of a selection of 33 species of Mantodea across the phylogeny including the early-diverging lineages Chaeteessa, Mantoida and Metallyticus, as well as representatives for the range of mantodean habitats. Scanning electron microscopy investigations revealed that both functional principles of animal attachment pads (smooth and hairy) are found within Mantodea: Chaeteessa, which is considered the sister group to all other mantises, features split tenent setae with spatula-shaped tips on their tarsal pads (euplantulae), while the remaining mantodean species possess smooth attachment pads. Some ecomorphological adaptations are observed among the studied species, such as pad asymmetry, ridge-like microstructures on the pad surfaces, and variations in the shape of the euplantulae However, these adaptations are much less pronounced and variable than the microstructural adaptations found in other Polyneoptera. The predatory behavior of mantises potentially results in less strict substrate-specific constraints on their attachment organs compared to herbivorous insect groups that evolved to specialize on certain plant surfaces. Furthermore, functional aspects of the morphological adaptations of the attachment systems of Mantodea are discussed.