Morphological ant mimics: constrained to imperfection?

Adaptive evolution relies on both heritable variation and selection. Variation is the raw material upon which selection acts, so any mechanism that limits or prevents the generation of heritable variation reduces the power of selection to lead to adaptation. Such limitations are termed evolutionary constraints. While it is widely accepted that constraints play an important role in shaping evolutionary outcomes, their relative importance, as opposed to adaptation, in determining evolutionary outcomes remains a subject of debate. Evolutionary constraints are often evoked as the reason behind the persistence of inaccurate mimicry. Here, we compared the variation and accuracy of body-shape mimicry in ant-mimicking spiders with that of ant-mimicking insects, predicting greater constraints, and hence inaccuracy, in spiders mimicking ants, due to their evolutionary distance from the ant model. We found high inter-species variation in mimetic accuracy, but dorsally, no overall difference in mimetic accuracy between spider and insect mimics, which is inconsistent with a constraint causing inaccurate mimicry. Our study provides empirical evidence suggesting that imperfect mimicry in spiders and insects is predominantly shaped by adaptive processes rather than constraints or chance. Our findings contribute to our understanding of the mechanisms underlying evolutionary diversity and the processes that shape phenotypic outcomes.

Chimairacoris flavipes sp. nov., (Hemiptera, Heteroptera, Miridae, Phylinae) from New Caledonia.

A new species, Chimairacoris flavipes Taszakowski & Cassis sp. nov. (Hemiptera, Heteroptera, Miridae, Phylinae), is described from New Caledonia. Habitus and SEM images of the female and necessary morphological structures are presented. The structure of the female genitalia is also shown in detail. An identification key and distributional map of known Chimairacoris species are provided.

Turrana ejuncida, a new species of Acanthocorini (Hemiptera: Heteroptera: Coreidae) from Cape Range, Western Australia, with discussion of its systematic position and host plant associations.

The coreid genus Turrana Distant 1911 is redescribed, and a new species Turrana ejuncida sp. nov. is described from specimens collected from Cape Range National Park, Western Australia in 2019 and 2021. Habitus photographs and scanning electron microscopy images are presented of key characters, with X-Ray microtomography deployed to document the male and female genitalia. In addition, DNA barcodes for mitochondrial gene regions COI and 16S were obtained and are made available on Genbank. Finally, the evidence provided in this work is discussed in relation to the systematic position of Turrana.

Five new genera of the subfamily Cylapinae (Insecta, Heteroptera, Miridae) from Australia.

Cylapinae is one of the poorly studied groups within the megadiverse family Miridae (Insecta: Heteroptera). In this paper, five monotypic genera from Australia are described as new to science. Two of those taxa, Dariella rubrocuneata gen. nov. and sp. nov., and Labriella fusca gen. nov. and sp. nov. are assigned to the tribe Cylapini. Three taxa, Callitropisca florentine gen. nov. and sp. nov., Laetifulvius morganensis gen. nov. and sp. nov. and Micanitropis seisia gen. nov. and sp. nov. are placed into the tribe Fulviini. Habitus images, SEMs of external characters, illustrations of male and female genitalia, and distribution maps are provided for each species where possible. The systematic position and possible relationships of the newly described taxa are discussed.

Quantifying vertebrate zoogeographical regions of Australia using geospatial turnover in the species composition of mammals, birds, reptiles and terrestrial amphibians.

A geospatial analysis of 1,906,302 records of 1938 species of Australian vertebrates has shown that the original regions proposed in the 19th century, namely the Eyrean, Torresian and Bassian still hold. The analysis has shown that the Eyrean region has an east-west divide, forming two, possibly independent arid regions (Eastern Desert and Western Desert provinces), that are shaped by topography and rainfall. A revised and interim zoogeographical area taxonomy of the Australian region is presented herein.

The complete mitochondrial genome of Zicrona caerulea (Linnaeus) (Hemiptera: Pentatomidae: Asopinae) and its phylogenetic implications.

Zicrona caerulea (Linnaeus, 1758) is a cosmopolitan stink bug species, which belongs to the predatory subfamily Asopinae. In this study, the complete mitochondrial genome of Zicrona caerulea from Shanxi, China was sequenced for the first time, using next generation sequencing. The mitogenome was found to be 15,479 bp in length. It contained 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a typical control region. This research revealed an overall A+T content of 77.14%. All tRNA genes had a clover-leaf structure except for trnS1, which lacks a dihydrouridine (DHU) arm; and for trnV, the DHU arm forms a simple loop. The lengths of rrnS and rrnL were 797 bp and 1,285 bp, respectively. Because of a shortage in tandem repeats, the A+T-rich region was 644 bp in length. Phylogenetic relationships based on these mitogenomes, using Bayesian inference and Maximum likelihood methods, showed that Zicrona caerulea belongs to Asopinae. The monophyly of families of the Pentatomoidea is supported, albeit limited taxon sampling.

Do phytogeographic patterns reveal biomes or biotic regions?

We present the largest comparative biogeographical analysis that has complete coverage of Australia's geography (20 phytogeographical subregions), using the most complete published molecular phylogenies to date of large Australian plant clades (Acacia, Banksia and the eucalypts). Two distinct sets of areas within the Australian flora were recovered, using distributional data from the Australasian Virtual Herbarium (AVH) and the Atlas of Living Australia (ALA): younger Temperate, Eremaean and Monsoonal biomes, and older southwest + west, southeast and northern historical biogeographical regions. The analyses showed that by partitioning the data into two sets, using either a Majority or a Frequency method to select taxon distributions, two equally valid results were found. The dataset that used a Frequency method discovered general area cladograms that resolved patterns of the Australian biomes, whereas if widespread taxa (Majority method, with >50% of occurrences outside a single subregion) were removed the analysis then recovered historical biogeographical regions. The study highlights the need for caution when processing taxon distributions prior to analysis as, in the case of the history of Australian phytogeography, the validity of both biomes and historical areas have been called into question.

Revisiting habitat and lifestyle transitions in Heteroptera (Insecta: Hemiptera): insights from a combined morphological and molecular phylogeny.

Heteroptera, the true bugs, are part of the largest clade of non-holometabolous insects, the Hemiptera, and include > 42 000 described species in about 90 families. Despite progress in resolving phylogenetic relationships between and within infraorders since the first combined morphological and molecular analysis published in 1993 (29 taxa, 669 bp, 31 morphological characters), recent hypotheses have relied entirely on molecular data. Weakly supported nodes along the backbone of Heteroptera made these published phylogenies unsuitable for investigations into the evolution of habitats and lifestyles across true bugs. Here we present the first combined morphological and molecular analyses of Heteroptera since 1993, using 135 taxa in 60 families, 4018 aligned bp of ribosomal DNA and 81 morphological characters, and various analytical approaches. The sister-group relationship of the predominantly aquatic Nepomorpha with all remaining Heteroptera is supported in all analyses, and a clade formed by Enicocephalomorpha, Dipsocoromorpha and Gerromorpha in some. All analyses recover Leptopodomorpha + (Cimicomorpha + Pentatomomorpha), mostly with high support. Parsimony- and likelihood-based ancestral state reconstructions of habitats and lifestyles on the combined likelihood phylogeny provide new insights into the evolution of true bugs. The results indicate that aquatic and semi-aquatic true bugs invaded these habitats three times independently from terrestrial habitats in contrast to a recent hypothesis. They further suggest that the most recent common ancestor of Heteroptera was predacious, and that the two large predominantly phytophagous clades (Trichophora and Miroidea) are likely to have derived independently from predatory ancestors. We conclude that by combining morphological and molecular data and employing various analytical methods our analyses have converged on a relatively well-supported hypothesis of heteropteran infraordinal relationships that now requires further testing using phylogenomic and more extensive morphological datasets.

Henryhalticusphilippinensis gen. et sp. n., a minute halticine from the Philippines (Insecta, Heteroptera, Miridae, Orthotylinae).

Henryhalticusphilippinensis gen. et sp. n. is described from a single location in the Negros Oriental Province of the Philippines. The male and female genitalia are described and illustrated. On the basis of the genitalic characters, external morphology, and size and color, the new species is erected as a monotypic genus.

Description of an enigmatic new genus and new species of Australian Orthotylinae (Insecta: Heteroptera: Miridae) associated with the plant genus Eremophila.

A new genus and new species of Australian orthotyline is described: Warrumiris viridis gen. nov. et. sp. nov. The species is widespread in Australia, mostly in arid and semi-arid regions of the continent. The species is associated with two species of the scrophulariaceous genus Eremophila. The species has highly autapomorphic male genitalia, with the aedeagus mostly membraneous with elongate lobal sclerites. The significance of the male genitalia is discussed.

Conservation Biology: A Walking Stick's Redux on Lord Howe Island.

Arguably the world's rarest insect - the Lord Howe Island 'tree lobster' - is being brought back from the brink. A recent study has confirmed the identity of this species using genomic data, which backstops its reintroduction to this World Heritage listed oceanic island.

A remarkable new plant bug genus and species (Hemiptera, Heteroptera, Miridae, Deraocorinae) from the Australian wet tropics.

A new genus and new species of deraeocorine plant bug, Kalamemiris gen. nov. and Kalamemiris collessi sp. nov., is described from Australia. Illustrations of male genitalia, scanning electron micrographs of key characters of the male and female habitus, as well as male genitalic characters are provided. The diagnosis of the new genus is made in comparison to other deraeocorines of the Australian biogeographic region.

Megadrymus brigalow n.sp. (Insecta: Hemiptera: Heteroptera: Rhyparochromidae: Drymini), a diminutive new species of seed bug from semi-evergreen vine thicket of the Queensland Brigalow Belt.

Megadrymus brigalow n. sp., a new species of seed bug, is described from semi-evergreen vine thicket in the Brigalow Belt region of Queensland, Australia. This species has the smallest body in the genus Megadrymus Gross and has a number of vestigial characters.

Traumatic insemination in terrestrial arthropods.

Traumatic insemination is a bizarre form of mating practiced by some invertebrates in which males use hypodermic genitalia to penetrate their partner's body wall during copulation, frequently bypassing the female genital tract and ejaculating into their blood system. The requirements for traumatic insemination to evolve are stringent, yet surprisingly it has arisen multiple times within invertebrates. In terrestrial arthropods traumatic insemination is most prevalent in the true bug infraorder Cimicomorpha, where it has evolved independently at least three times. Traumatic insemination is thought to occur in the Strepsiptera and has recently been recorded in fruit fly and spider lineages. We review the putative selective pressures that may have led to the evolution of traumatic insemination across these lineages, as well as the pressures that continue to drive divergence in male and female reproductive morphology and behavior. Traumatic insemination mechanisms and attributes are compared across independent lineages.

Surviving in sympatry: paragenital divergence and sexual mimicry between a pair of traumatically inseminating plant bugs.

Reproductive interactions between species can carry significant costs (e.g., wasted time, energy, and gametes). In traumatically inseminating insects, heterospecific mating costs may be intensified, with indiscriminate mating and damaging genitalia leading to damage or death. When closely related traumatically inseminating species are sympatric, we predict selection should favor the rapid evolution of reproductive isolation. Here we report on a cryptic species of traumatically inseminating plant bug, Coridromius taravao, living sympatrically with its sister species, Coridromius tahitiensis, in French Polynesia. Despite their sister-species relationship, they exhibit striking differences in reproductive morphology, with females of each species stabbed and inseminated through different parts of their abdomens. Furthermore, C. tahitiensis is sexually dimorphic in coloration and vestiture, while both sexes of C. taravao share the C. tahitiensis male expression of these traits. These findings support a role for (1) reproductive character divergence and (2) interspecies sexual mimicry in limiting interspecific mating brought about by indiscriminate male mating behavior.

Systematics of the lace bug genus Cottothucha Drake and Poor (Insecta: Hemiptera: Heteroptera: Tingidae) with description of the first Australian species and its exaggerated nymph.

The lace bug genus Cottothucha is redescribed. Cottothucha kalathis from Australia is described as new to science. The fifth instar for C. kalathis is described and illustrated. Cottothucha minor and Cottothucha oceanae are redescribed. The male genitalia of these species are illustrated. The pronotal cyst is compared between the species and its evolution is discussed. The genus is maintained within the lace bug tribe Litadeini based on an enlarged tarsal segment.

Towards an Australian Bioregionalisation Atlas: A provisional area taxonomy of Australia's biogeographical regions.

The large number, definition, varied application and validity of named Australian biogeographical regions reflect their ad hoc development via disparate methods or case study idiosyncracies. They do not represent a coherent system. In order to resolve these uncertainties an Australian Bioregionalisation Atlas is proposed as a provisional hierarchical classification, accounting for all known named areas. This provisional area taxonomy includes a diagnosis, description, type locality and map for each named area within the Australian continent, as well as a first-ever area synonymy. Akin to biological classifications, this Atlas seeks to provision universality, objectivity and stability, such that biogeographers, macroecologists and geographers, can test existing areas as well as proposing novel areas. With such a formalised and comparative system in place, practitioners can analyse the definition and relationships of biotic areas, and putatively minimise ad hoc explanations.

Human remains from the Pleistocene-Holocene transition of southwest China suggest a complex evolutionary history for East Asians.

BACKGROUND: Later Pleistocene human evolution in East Asia remains poorly understood owing to a scarcity of well described, reliably classified and accurately dated fossils. Southwest China has been identified from genetic research as a hotspot of human diversity, containing ancient mtDNA and Y-DNA lineages, and has yielded a number of human remains thought to derive from Pleistocene deposits. We have prepared, reconstructed, described and dated a new partial skull from a consolidated sediment block collected in 1979 from the site of Longlin Cave (Guangxi Province). We also undertook new excavations at Maludong (Yunnan Province) to clarify the stratigraphy and dating of a large sample of mostly undescribed human remains from the site. METHODOLOGY/PRINCIPAL FINDINGS: We undertook a detailed comparison of cranial, including a virtual endocast for the Maludong calotte, mandibular and dental remains from these two localities. Both samples probably derive from the same population, exhibiting an unusual mixture of modern human traits, characters probably plesiomorphic for later Homo, and some unusual features. We dated charcoal with AMS radiocarbon dating and speleothem with the Uranium-series technique and the results show both samples to be from the Pleistocene-Holocene transition: ∼14.3-11.5 ka. CONCLUSIONS/SIGNIFICANCE: Our analysis suggests two plausible explanations for the morphology sampled at Longlin Cave and Maludong. First, it may represent a late-surviving archaic population, perhaps paralleling the situation seen in North Africa as indicated by remains from Dar-es-Soltane and Temara, and maybe also in southern China at Zhirendong. Alternatively, East Asia may have been colonised during multiple waves during the Pleistocene, with the Longlin-Maludong morphology possibly reflecting deep population substructure in Africa prior to modern humans dispersing into Eurasia.