Laura C.V. Breitkreuz

The Evolving Theory of Evolutionary Radiations

Evolutionary radiations have intrigued biologists for more than 100 years, and our understanding of the patterns and processes associated with these radiations continues to grow and evolve. Recently it has been recognized that there are many different types of evolutionary radiation beyond the well-studied adaptive radiations. We focus here on multifarious types of evolutionary radiations, paying special attention to the abiotic factors that might trigger diversification in clades. We integrate concepts such as exaptation, species selection, coevolution, and the turnover-pulse hypothesis (TPH) into the theoretical framework of evolutionary radiations. We also discuss other phenomena that are related to, but distinct from, evolutionary radiations that have relevance for evolutionary biology.

The first Mesozoic microwhip scorpion (Palpigradi): a new genus and species in mid-Cretaceous amber from Myanmar

A fossil palpigrade is described and figured from mid-Cretaceous (Cenomanian) amber from northern Myanmar. Electrokoenenia yaksha Engel and Huang, gen. n. et sp. n., is the first Mesozoic fossil of its order and the only one known as an inclusion in amber, the only other fossil being a series of individuals encased in Pliocene onyx marble and 94–97 million years younger than E. yaksha. The genus is distinguished from other members of the order but is remarkably consistent in observable morphological details when compared to extant relatives, likely reflecting a consistent microhabitat and biological preferences over the last 100 million years.

Evolution of lacewings and allied orders using anchored phylogenomics (Neuroptera, Megaloptera, Raphidioptera)

Analysis of anchored hybrid enrichment (AHE) data under a variety of analytical parameters for a broadly representative sample of taxa (136 species representing all extant families) recovered a well‐resolved and strongly supported tree for the higher phylogeny of Neuropterida that is highly concordant with previous estimates based on DNA sequence data. Important conclusions include: Megaloptera is sister to Neuroptera; Coniopterygidae is sister to all other lacewings; Osmylidae, Nevrorthidae and Sisyridae are recovered as a monophyletic Osmyloidea, and Rhachiberothidae and Berothidae were recovered within a paraphyletic Mantispidae. Contrary to previous studies, Chrysopidae and Hemerobiidae were not recovered as sister families and morphological similarities between larvae of both families supporting this assumption are reinterpreted as symplesiomorphies. Relationships among myrmeleontoid families are similar to recent studies except Ithonidae are placed as sister to Nymphidae. Notably, Ascalaphidae render Myrmeleontidae paraphyletic, again calling into question the status of Ascalaphidae as a separate family. Using statistical binning of partitioned loci based on a branch‐length proxy, we found that the diversity of phylogenetic signal across partitions was minimal from the slowest to the fastest evolving loci and varied little over time. Ancestral character‐state reconstruction of the sclerotization of the gular region in the larval head found that although it is present in Coleoptera, Raphidioptera and Megaloptera, it is lost early in lacewing evolution and then regained twice as a nonhomologous gula‐like sclerite in distantly related clades. Reconstruction of the ancestral larval habitat also indicates that the ancestral neuropteridan larva was aquatic, regardless of the assumed condition (i.e., aquatic or terrestrial) of the outgroup (Coleopterida).

Phylogeny and Evolution of Neuropterida: Where Have Wings of Lace Taken Us?

The last 25 years of phylogenetic investigation into the three orders constituting the superorder Neuropterida-Raphidioptera, Megaloptera, and Neuroptera-have brought about a dramatic revision in our understanding of the evolution of lacewings, snakeflies, dobsonflies, and their diverse relatives. Phylogenetic estimations based on combined analyses of diverse data sources, ranging from adult and larval morphology to full mitochondrial genomic DNA, have begun to converge on similar patterns, many times in accordance with hypotheses put forth by Cyril Withycombe nearly a century ago. These data, in combination with information from the fossil record, have given a revised perspective on the historical evolution and classification of Neuropterida, necessitating an overhaul of their organization and providing focus and insight on fruitful future efforts for neuropterology.

Early Morphological Specialization for Insect-Spider Associations in Mesozoic Lacewings.

Insects exhibit a wide diversity of anatomical specializations in their adult and immature stages associated with particular aspects of their biology. The order Neuroptera (lacewings, antlions, and their relatives) are a moderately diverse lineage of principally predatory animals, at least in their immature stages, as all have a modified piercing-sucking mandible-maxillary complex that allows them to drain fluids from their prey. As such, the larvae of various groups have evolved unique anatomical and behavioral specializations for approaching and subduing their prey, particularly the green lacewings (Chrysopidae), where immatures are also adept at camouflage [1-4]. Here we report the discovery of a unique mode of life among mid-Cretaceous mesochrysopids, an early stem group to modern green lacewings [5-7] exhibiting a combination of morphological modifications in both adults and larvae unknown among living and fossil Neuroptera, even across winged insects. The new mesochrysopids exhibit a uniquely prolonged thorax, elongate legs, and dramatically reduced hind wings in adults, and larvae have extremely elongate, slender legs with pectinate pretarsal claws and lacking trumpet-shaped empodia. The peculiarities of the larvae include features principally found in spider-associated insect groups, implying that these lacewings were early specialists on web-spinning spiders, either as active predators or kleptoparasites. This reveals a dramatic and ancient degree of ecological refinement in a major lineage of insect predators, for a food resource otherwise not utilized by most lacewings.

Wing Tracheation in Chrysopidae and Other Neuropterida (Insecta): A Resolution of the Confusion about Vein Fusion

ABSTRACT The wings of insects are one of their most prominent features and embody numerous characters and modifications congruent with the variety of their lifestyles. However, despite their evolutionary relevance, homology statements and nomenclature of wing structures remain understudied and sometimes confusing. Early studies on wing venation homologies often assumed Neuropterida (the superorder comprising the orders Raphidioptera, Megaloptera, and Neuroptera: snakeflies, alderflies and dobsonflies, and lacewings) to be ancient among Pterygota, and therefore relied on their pattern of venation for determining groundplans for insect wing venation schemata and those assumptions reciprocally influenced the interpretation of lacewing wings. However, Neuropterida are in fact derived among flying insects and thus a reconsideration of their wings is crucial. The identification of the actual wing venation of Neuropterida is rendered difficult by fusions and losses, but these features provide systematic and taxonomically informative characters for the classification of the different clades within the group. In the present study, we review the homology statements of wing venation among Neuropterida, with an emphasis on Chrysopidae (green lacewings), the family in which the highest degree of vein fusion is manifest. The wing venation of each order is reviewed according to tracheation, and colored schemata of the actual wing venation are provided as well as detailed illustrations of the tracheation in select families. According to the results of our study of vein tracheation, new homology statements and a revised nomenclature for veins and cells are proposed.

Revision of the green lacewing subgenus Ankylopteryx (Sencera) (Neuroptera, Chrysopidae)

Abstract The Australasian and Oriental green lacewing subgenus Ankylopteryx (Sencera) Navás (Chrysopinae: Ankylopterygini) is examined and its diversity and placement among other members of the tribe Ankylopterygini is discussed. After study of specimens spanning the full distribution and anatomical range of variation for the subgenus, all prior putative species, resulting in the sole valid species are newly synonymized, Ankylopteryx (Sencera) anomala (Brauer). Accordingly, the following new synonymies are established: Sencera scioneura Navás, syn. n., Sencera feae Navás, syn. n., and Sencera exquisita Nakahara, syn. n. [all under the name Ankylopteryx (Sencera) anomala]. A lectotype is newly designated for Ankylopteryx (Sencera) anomala so as to stabilize the application of the name. To support our hypotheses, the wing and general body coloration as well as the male genitalia are reviewed. We elaborate on the possibility of Ankylopteryx (Sencera) anomala being nothing more than an autapomorphic species of Ankylopteryx Brauer, as it was originally described. The species is not sufficiently distinct to warrant recognition as a separate subgenus within the group, and most certainly not as its own genus as has been advocated by past authors. Nonetheless, we do not for now go so far as to synonymize the subgenus until a more extensive phylogenetic analysis is undertaken with multiple representative species from across Ankylopteryx and other ankylopterygine genera. Lastly, we comment on the biology of Ankylopteryx (Sencera) anomala in terms of the attraction of males to methyl eugenol and on the widespread practice of splitting within Chrysopidae.

Getting somewhere with the Red Queen: chasing a biologically modern definition of the hypothesis

The Red Queen hypothesis (RQH) is both familiar and murky, with a scope and range that has broadened beyond its original focus. Although originally developed in the palaeontological arena, it now encompasses many evolutionary theories that champion biotic interactions as significant mechanisms for evolutionary change. As such it de-emphasizes the important role of abiotic drivers in evolution, even though such a role is frequently posited to be pivotal. Concomitant with this shift in focus, several studies challenged the validity of the RQH and downplayed its propriety. Herein, we examine in detail the assumptions that underpin the RQH in the hopes of furthering conceptual understanding and promoting appropriate application of the hypothesis. We identify issues and inconsistencies with the assumptions of the RQH, and propose a redefinition where the Red Queens reign is restricted to certain types of biotic interactions and evolutionary patterns occurring at the population level.

A review of the New Caledonian Arpactophilus (Hymenoptera: Crabronidae)

The diverse and unique fauna of the apoid wasp genus Arpactophilus Smith (Pemphredoninae: Stigmini: Spilomenina) occurring in New Caledonia is reviewed. The previously documented diversity of 17 species is expanded to a total of 48, with 31 new species described and figured from across the main island. The new species proposed here are: Arpactophilus arha, A. arhoe, A. bwatoo, A. caac, A. cemuhi, A. drehu, A. drubea, A. fagauvea, A. futuna, A. fwai, A. haveke, A. iaai, A. jawe, A. kumak, A. merle, A. nemi, A. nengone, A. nere, A. numee, A. nyelayu, A. orowe, A. paici, A. pije, A. pwaamei, A. pwapwa, A. tayo, A. tiri, A. vamale, A. xaracuu, A. xaragure, and A. yuanga, spp. nov. Diagnoses are provided for those previously described species and a key to the fauna presented, although six species are considered of uncertain identity: A. arboreus Bohart, A. dolichocara Bohart, A. kraussi Bohart, A. nemoralis Bohart, A. nigripes Bohart, and A. sylvaticus Bohart. Brief comments are made regarding the unique species radiation occurring in New Caledonia and the potential for future discoveries in the systematics and biology of Australasian Arpactophilus.