Evolution of the praying mantids: a morphological perspective

Mantodea are a predatory group of polyneopteran insects, comprising approximately 2,400 species in nearly 440 genera. Their distribution covers all warmer regions across a diversity of habitats including rainforests to deserts. In 2009, the most comprehensive molecular dataset, covering nearly 300 species from all families was published by Svenson & Whiting [Cladistics 25: 468-514]. The results were consistent with biogeography rather than traditional taxonomy. Furthermore, many of the putative synapomorphic morphological characters that lead to current taxonomy are homoplastic and multiple convergences based on similar selective pressures probably led to similar morphological ecotypes. The first extensive morphological dataset has been encoded; it includes 152 external characters for 122 representative species. The resulting phylogeny shows most characters to be homoplastic, supporting aspects of the molecular data. Many traditional taxa were found to be para- or polyphyletic. However, several groups, including Eremiaphilidae, Empusidae, Toxoderidae, Amorphoscelinae, Perlamantinae, Paraoxypilinae, and Haaniinae (nested within Oligonicinae), were recovered as well-supported groups with strong morphological autapomorphies. The basal dichotomies within Mantodea were recovered as [Chaeteessa] + ([Metallyticus] + [Mantoida + remaining Mantodea]); this result differs from the molecular findings and previous morphological studies (i.e. Klass & Meier [2006] Entomologische Abhandlungen 63[1-2]: 3-50). In Klass & Meier, Mantoida was found to be the sister group of the remaining Mantodea with the possibility of Metallyticus nested in a more apical position in the cladogram. The present analysis supports multiple convergent origins of many morphological structures including the enormous pronotal expansions found in several species, head processes exhibited by various species, and others. A single origin of the metathoracic ear, as postulated by Yager & Svenson (2008: Biological Journal of the Linnean Society 94: 541-568) and Svenson & Whiting (2009), is not supported by the morphological data.