Adult external morphology of the extant raptorial Mantispoidea (Insecta: Neuroptera: Mantispidae and Rhachiberothidae) is compared emphasizing the morphology of the subfamily Symphrasinae as a key group to understand the phylogenetic relationships among the members of the superfamily. Plega dactylota Rehn, 1939 is thoroughly characterized in order to exemplify the morphology of the Symphrasinae. Additionally, following a review of the literature and examination of comparative material of Dilaridae, Berothidae, Rhachiberothidae and all Mantispidae subfamilies, a new interpretation of the components of the raptorial apparatus (i.e., head, prothorax, grasping forelegs, as well as integumentary specializations) is presented. Also, wing venation for these groups is reinterpreted, and new homology hypotheses for wing venation are proposed based on tracheation and comparative analyses. Given the high morphological divergence on the genital sclerites within the Mantispoidea, plus the confusing previous usage of neutral terminology and terms referring to appendages across taxonomic and morphological studies, we attempt to standardize, simplify, and situate terminology in an evolutionary context under the “gonocoxite concept” (multi-coxopod hypothesis). The remarkable morphological similarity of the genital sclerites of Symphrasinae and Rhachiberothidae (sensu U. Aspöck & Mansell 1994) with the Nallachinae (Dilaridae) was taken as a starting point to understand the morphology of other Mantispidae subfamilies. Based on these morphological comparisons, we provide a revised phylogenetic analysis of Mantispoidea. This new phylogenetic analysis supports a sister group relationship between the family Rhachiberothidae, comprising Rhachiberothinae and Symphrasinae, and the family Mantispidae, including the subfamily Mantispinae and its sister taxa Drepanicinae and Calomantispinae, which may represent a single subfamily. Based on these analyses, raptorial condition probably evolved a single time in these insects and subsequently became diversified in the two sister clades of the raptorial Mantispoidea.

Species of the thorny lacewing subfamily Symphrasinae (Neuroptera: Rhachiberothidae) are revised. Prior to this work, 42 species were known in the genera Anchieta Navás, 1909, Plega Navás, 1928, and Trichoscelia Westwood, 1852. Herein, the number of species is increased to 60, 23 of which are newly described. Species previously known are redescribed, and their taxonomic status is revised. Keys, diagnoses, and high-resolution images for all species are presented. The distribution range of Anchieta is now known from Costa Rica to southern Brazil with a total of 11 species, of which three are newly described. The genus Plega is known from southwestern United States to southern Brazil and includes 28 species of which 14 are described as new. Moreover, the genus Trichoscelia occurs from central and southern Mexico to Argentina, with a total of 21 species, of which six are herein newly described. A phylogenetic analysis of Symphrasinae based on morphological characters recovered the three symphrasine genera as monophyletic, with Anchieta sister to Plega + Trichoscelia. The three genera are newly diagnosed based on a cladistic framework. Within the genus Anchieta, bee-mimicking species comprise a monophyletic group, while wasp-mimicking species form a laddered sequence to that lineage. Within Plega, three lineages are recovered, the first mostly composed of South and Mesoamerican species, the second with species predominantly from Central America and central and southern Mexico, and a third clade encompassing species mostly from central and northern Mexico and southwestern United States. By contrast, relationships between species of Trichoscelia were poorly resolved because of a simplified and conserved morphology of this group.

The genus Plega Navás, 1928, belongs to the subfamily Symphrasinae, a group recently transferred from Mantispidae to Rhachiberothidae. This genus is herein reported as parasitoid of the symphytan family Diprionidae for the first time, becoming the first record of association between this neuropteran subfamily and non-aculeate Hymenoptera. This new association was discovered in “Ixcateopan de Cuauhtémoc”, in the Mexican state of Guerrero, where Plega spinosa Ardila et al., 2019 was found associated with immatures of the sawfly Monoctenus cuauhtemoci De Lira, 2021, a pest in forests of Juniperus flaccida Schlechtendal (white cedar). The neuropteran was found to be the most abundant parasitoid of this symphytan, becoming a potential candidate for biological control of phytophagous sawflies in juniper forests, an economically important plant species for the wood industry in the region. Considering the behavior and morphological aspects of the primary larvae and the behavior of the adults of Plega, three possible scenarios in which the primary larvae of P. spinosa board the larvae of Monoctenus to complete its life cycle are outlined. This finding reinforces the hypothesis of a generalist ectoparasitoid lifeway of the larvae of the genus Plega on larvae and pupae of holometabolous insects.

Megaloptera belong to a large monophyletic group, the Neuropteroidea, together with Coleoptera, Strepsiptera, Raphidioptera, and Neuroptera. With the latter two, this order constitutes the Neuropterida, a smaller monophyletic subset among which it is the only entirely aquatic group, with larvae of all species requiring submersion in freshwater. Megaloptera is arguably the oldest extant clade of Holometabola with aquatic representatives, having originated during the Permian before the fragmentation of Pangea, since about 230 Ma. It includes 54 genera (35 extant and 19 extinct genera), with 397 extant described species and subspecies. Recent Megaloptera are divided into two families: Corydalidae (with subfamilies Corydalinae—dobsonflies and Chauliodinae—fishflies) and Sialidae (alderflies), both widely yet disjunctively distributed among zoogeographical realms. All species of Megaloptera have aquatic larvae, whereas eggs, pupae, and adults are terrestrial. The anatomy, physiology, and behavior of megalopteran larvae are specialized for an aquatic predatory habit, yet their ecological significance might still be underappreciated, as their role in food webs of benthic communities of many temperate and tropical streams and rivers is still understudied and largely unquantified. In many freshwater ecosystems, Megaloptera larvae are a conspicuous benthic component, important in energy flow, recycling of materials, and food web dynamics.

Phylogenetic review of dobsonflies of the subfamily Corydalinae and the genus Corydalus Latreille (Megaloptera: Corydalidae)