Signatures of increasing environmental stress in bumblebee wings over the past century: Insights from museum specimens.

Determining when animal populations have experienced stress in the past is fundamental to understanding how risk factors drive contemporary and future species' responses to environmental change. For insects, quantifying stress and associating it with environmental factors has been challenging due to a paucity of time-series data and because detectable population-level responses can show varying lag effects. One solution is to leverage historic entomological specimens to detect morphological proxies of stress experienced at the time stressors emerged, allowing us to more accurately determine population responses. Here we studied specimens of four bumblebee species, an invaluable group of insect pollinators, from five museums collected across Britain over the 20th century. We calculated the degree of fluctuating asymmetry (FA; random deviations from bilateral symmetry) between the right and left forewings as a potential proxy of developmental stress. We: (a) investigated whether baseline FA levels vary between species, and how this compares between the first and second half of the century; (b) determined the extent of FA change over the century in the four bumblebee species, and whether this followed a linear or nonlinear trend; (c) tested which annual climatic conditions correlated with increased FA in bumblebees. Species differed in their baseline FA, with FA being higher in the two species that have recently expanded their ranges in Britain. Overall, FA significantly increased over the century but followed a nonlinear trend, with the increase starting c. 1925. We found relatively warm and wet years were associated with higher FA. Collectively our findings show that FA in bumblebees increased over the 20th century and under weather conditions that will likely increase in frequency with climate change. By plotting FA trends and quantifying the contribution of annual climate conditions on past populations, we provide an important step towards improving our understanding of how environmental factors could impact future populations of wild beneficial insects.

Mind the Outgroup and Bare Branches in Total-Evidence Dating: a Case Study of Pimpliform Darwin Wasps (Hymenoptera, Ichneumonidae).

Taxon sampling is a central aspect of phylogenetic study design, but it has received limited attention in the context of total-evidence dating, a widely used dating approach that directly integrates molecular and morphological information from extant and fossil taxa. We here assess the impact of commonly employed outgroup sampling schemes and missing morphological data in extant taxa on age estimates in a total-evidence dating analysis under the uniform tree prior. Our study group is Pimpliformes, a highly diverse, rapidly radiating group of parasitoid wasps of the family Ichneumonidae. We analyze a data set comprising 201 extant and 79 fossil taxa, including the oldest fossils of the family from the Early Cretaceous and the first unequivocal representatives of extant subfamilies from the mid-Paleogene. Based on newly compiled molecular data from ten nuclear genes and a morphological matrix that includes 222 characters, we show that age estimates become both older and less precise with the inclusion of more distant and more poorly sampled outgroups. These outgroups not only lack morphological and temporal information but also sit on long terminal branches and considerably increase the evolutionary rate heterogeneity. In addition, we discover an artifact that might be detrimental for total-evidence dating: "bare-branch attraction," namely high attachment probabilities of certain fossils to terminal branches for which morphological data are missing. Using computer simulations, we confirm the generality of this phenomenon and show that a large phylogenetic distance to any of the extant taxa, rather than just older age, increases the risk of a fossil being misplaced due to bare-branch attraction. After restricting outgroup sampling and adding morphological data for the previously attracting, bare branches, we recover a Jurassic origin for Pimpliformes and Ichneumonidae. This first age estimate for the group not only suggests an older origin than previously thought but also that diversification of the crown group happened well before the Cretaceous-Paleogene boundary. Our case study demonstrates that in order to obtain robust age estimates, total-evidence dating studies need to be based on a thorough and balanced sampling of both extant and fossil taxa, with the aim of minimizing evolutionary rate heterogeneity and missing morphological information. [Bare-branch attraction; ichneumonids; fossils; morphological matrix; phylogeny; RoguePlots.].

Phylogenomics of Ichneumonoidea (Hymenoptera) and implications for evolution of mode of parasitism and viral endogenization.

Ichneumonoidea is one of the most diverse lineages of animals on the planet with >48,000 described species and many more undescribed. Parasitoid wasps of this superfamily are mostly beneficial insects that attack and kill other arthropods and are important for understanding diversification and the evolution of life history strategies related to parasitoidism. Further, some lineages of parasitoids within Ichneumonoidea have acquired endogenous virus elements (EVEs) that are permanently a part of the wasp's genome and benefit the wasp through host immune disruption and behavioral control. Unfortunately, understanding the evolution of viral acquisition, parasitism strategies, diversification, and host immune disruption mechanisms, is deeply limited by the lack of a robust phylogenetic framework for Ichneumonoidea. Here we design probes targeting 541 genes across 91 taxa to test phylogenetic relationships, the evolution of parasitoid strategies, and the utility of probes to capture polydnavirus genes across a diverse array of taxa. Phylogenetic relationships among Ichneumonoidea were largely well resolved with most higher-level relationships maximally supported. We noted codon use biases between the outgroups, Braconidae, and Ichneumonidae and within Pimplinae, which were largely solved through analyses of amino acids rather than nucleotide data. These biases may impact phylogenetic reconstruction and caution for outgroup selection is recommended. Ancestral state reconstructions were variable for Braconidae across analyses, but consistent for reconstruction of idiobiosis/koinobiosis in Ichneumonidae. The data suggest many transitions between parasitoid life history traits across the whole superfamily. The two subfamilies within Ichneumonidae that have polydnaviruses are supported as distantly related, providing strong evidence for two independent acquisitions of ichnoviruses. Polydnavirus capture using our designed probes was only partially successful and suggests that more targeted approaches would be needed for this strategy to be effective for surveying taxa for these viral genes. In total, these data provide a robust framework for the evolution of Ichneumonoidea.

The potential of the solitary parasitoid Microctonus brassicae for the biological control of the adult cabbage stem flea beetle, Psylliodes chrysocephala.

The cabbage stem flea beetle (CSFB), Psylliodes chrysocephala L. (Coleoptera: Chrysomelidae), is a major pest of oilseed rape, Brassica napus L. (Brassicaceae), within the UK and continental Europe. Following the withdrawal of many broad-spectrum pesticides, most importantly neonicotinoids, and with increased incidence of pyrethroid resistance, few chemical control options remain, resulting in the need for alternative pest management strategies. We identified the parasitoid wasp Microctonus brassicae (Haeselbarth) (Hymenoptera: Braconidae) within CSFB collected from three independent sites in Norfolk, UK. Parasitism of adult CSFB was confirmed, and wasp oviposition behaviour was described. Moreover, we show that within captive colonies parasitism rates are sufficient to generate significant biological control of CSFB populations. A sequence of the M. brassicae mitochondrial cytochrome oxidase 1 (MT-CO1) gene was generated for rapid future identification. Moroccan specimens of Microctonus aethiopoides (Loan), possessing 90% sequence similarity, were the closest identified sequenced species. This study represents the first description published in English of this parasitoid of the adult cabbage stem flea beetle.

First record of the genus Aplomerus Provancher, 1886 (Hymenoptera: Ichneumonidae: Xoridinae) from the Oriental region, with descriptions of two new species.

The genus Aplomerus Provancher, 1886 (Hymenoptera, Ichneumonidae) is a small genus of the subfamily Xoridinae. Two new species from Asia, A. orientalis Varga & Reshchikov sp. n. from Thailand and A. phamae Broad sp. n. from Vietnam, are described and illustrated. An identification key for Asian species is provided. These are the first records of the genus from the Oriental region and increases the known number of Aplomerus species to eight, with a disjunct distribution of North America, Japan and south-east Asia.

Twenty seven new species of Orthocentrus (Hymenoptera: Ichneumonidae; Orthocentrinae) with a key to the Neotropical species of the genus.

We describe 27 new species of parasitoid wasps of the genus Orthocentrus (Ichneumonidae: Orthocentrinae) from the Neotropical region, where previously only one species of the genus (O. insularis Ashmead) was known, and provide a key to all described Orthocentrus species of the region. Based on previous studies and additional material that we have seen from the region, describing these species is only an initial attempt to document the Neotropical orthocentrine fauna.

The neotropical species of Xanthopimpla Saussure (Hymenoptera: Ichneumonidae: Pimplinae).

Xanthopimpla Saussure, 1892 is one of the largest and best studied genera of the family Ichneumonidae. It is most species rich in the Oriental and Afrotropical regions with only a few species occurring in Central and South America. The present study reviews the Neotropical species of the genus including descriptions of four new species from Amazonia and Northeast South America. We define a new species group: the amazonica species-group, to accommodate the following five species: X. amazonica Gómez, Sääksjärvi & Veijalainen, X. guianensis Gómez & Sääksjärvi sp. n., X. jussilai Veijalainen, Sääksjärvi & Broad, X. pucallpensis Gómez & Sääksjärvi sp. n. and X. vidali Gómez sp. n. The aurita species-group, which had hitherto been regarded as the only species-group in the Neotropical region, is currently represented by five species: X. allpahuaya Gómez & Sääksjärvi sp. n., X. aurita Krieger, X. craspedoptera Krieger, X. rhabdomera Townes and X. spiloptera Krieger. The Andean species X. peruana Krieger is established as an unplaced species outside of the amazonica and aurita species-groups. A key to Neotropical species-groups and species of Xanthopimpla is provided. Xanthopimpla aurita is recorded for the first time from Ecuador and Colombia and its extensive distribution is discussed. Xanthopimpla amazonica, X. craspedoptera and X. jussilai are recorded for the first time from Brazil; X. amazonica is recorded for the first time from French Guiana; X. spiloptera is recorded for the first time from French Guiana and Peru, and X. rhabdomera is recorded for the first time from Peru. 

New Species of Grotea (Hymenoptera, Ichneumonidae, Labeninae) from Ecuador, with New Records and a Key to the Neotropical Species.

Here we describe two new Grotea species from Ecuador, G. akakana Mazón & Bordera sp. nov., and G. romeri Mazón sp. nov., as well as the male of G. cundinamarquesa Herrera-Flórez 2018. G. akakana sp. nov. is characterized by the combination of a postgenal process long, a 45-flagellomeres antenna without a white band and a mesopleuron black with two yellow spots separated by a red one. On the other hand, G. romeri sp. nov. is characterized by the combination of a postgenal process very short, a 36-flagellomeres antenna without a white band, a propodeum with a long and narrow area lateralis, uninterrupted yellow-colored orbits and a mesopleuron black with a yellow spot in the middle. The species G. santandereana Herrera-Flórez 2018 and G. surinamese Herrera-Flórez 2019 are recorded from Ecuador for the first time. This brings the total of described Grotea species to 31, all from the New World, with 27 of these exclusively Neotropical. A key for the identification of Neotropical species is included.

The ectoparasitoid wasp Heterospilussicanus (Marshall, 1888) (Hymenoptera, Braconidae, Doryctinae) as a natural enemy of Gastralluspubens Fairmaire, 1875 (Coleoptera, Ptinidae) in Italy.

Heterospilussicanus (Marshall, 1888) is redescribed and illustrated based on the holotype of Dendrosotersicanus Marshall, 1888 and on recently collected material from its type locality (Sicily, Italy). Previous host records for this species are unreliable. Here, the host of H.sicanus, the rare ptinid beetle Gastralluspubens Fairmaire, 1875, is recorded for the first time, having been reared in a historic library in Palermo, Italy. Heterospilussicanus is compared with the similar species Telebolus (= Heterospilus) corsicus Marshall, 1888, which was described in the same monograph from Corsica (France), and it is also redescribed and illustrated. Atoreuteusceballosi Docavo Alberti, 1960, syn. nov. is synonymised under Heterospilussicanus (Marshall, 1888), and Hormiopterus (= Rhaconotus) ollivieri Giraud var. flava Fahringer, 1931, syn. nov. is a junior synonym of Heterospiluscephi Rohwer, 1925. A key for determination of the Western Palaearctic Heterospilus species with a striate vertex is provided and the distributions of H.sicanus and H.corsicus are discussed.

Species richness estimation of the Afrotropical Darwin wasps (Hymenoptera, Ichneumonidae).

Species richness is one of the fundamental metrics of biodiversity. Estimating species richness helps spotlight taxonomic groups that are particularly under-studied, such as the highly diverse Darwin wasps. The only available estimate of the number of Darwin wasps in the Afrotropics proposed almost 11,000 species, compared to the 2,322 recorded species. However, it relied exclusively on the ratio of morphospecies to described species in Henry Townes' personal collection. We provide an updated estimate of the Afrotropical Darwin wasp species, using empirical data from multiple sources, including the increase in species numbers following generic revisions, morphospecies sorting in natural history collections, and diversity patterns of better-studied insects (butterflies) for extrapolation. Our analyses suggest that our knowledge of Darwin wasps is highly incomplete, with only 13-22% of species known in the five most extensively studied countries in the Afrotropics. We estimate 9,206-15,577 species of Darwin wasps within the entire Afrotropics, with the highest concentration expected in the Equatorial Afrotropics and Madagascar. Due to data constraints, our approach tends to underestimate diversity at each step, rendering the upper estimate (15,577 species) more realistic. We highlight reasons contributing to the gap between recorded and estimated species richness, including logistical and financial factors, as well as post-colonial influences.

Tersilochinae (Hymenoptera: Ichneumonidae) of Costa Rica, Part 2. Genera Megalochus gen. nov. and Stethantyx Townes.

Two Costa Rican genera, Megalochus gen. nov. and Stethantyx Townes, are revised. These genera comprise a distinctive generic group that we refer to as the Stethantyx genus-group, veins Rs+2r and Rs angled more than 90 degrees, vein 2rs-m and abscissa of M between 2rs-m and 2m-cu not or very weakly thickened, hind wing with vein cul&cu-a (nervellus) more or less vertical, and prepectal carina with upper end not reaching anterior margin of mesopleuron, continuing above and backwards to the subtegular ridge. Both genera include medium sized to large species with body length 4.0 to 15.0 mm. Megalochus comprises only the type species, M. grandis sp. nov., occurring in Costa Rica, Ecuador and southern Brazil. It is the largest representative of the subfamily, with a body length of 10.5 to 15.0 mm. Megalochus differs from Stethantyx, besides the larger body size, by the slenderer first metasomal segment, which is round in cross-section and lacking glymmae, propodeum and metapleuron with coarse rugae, and shortened antennae with strongly transverse flagellomeres. Stethantyx is the dominant, most species-rich genus in the Costa Rican tersilochine fauna and probably in the Neotropical region. Twenty two species of this genus were discovered in Costa Rica, all are new: S. alajuela sp. nov., S. altamira sp. nov., S. aprica sp. nov., S. cacaoensis sp. nov., S. cartagoa sp. nov., S. cecilia sp. nov., S. curvator sp. nov., S. guanacasteca sp. nov., S. heredia sp. nov., S. limona sp. nov., S. mesoscutator sp. nov., S. niger sp. nov., S. nigrofemorata sp. nov., S. notaulator sp. nov., S. orosia sp. nov., S. osa sp. nov., S. propodeator sp. nov., S. pseudoorosia sp. nov., S. pseudoosa sp. nov., S. puntarenasa sp. nov., S. sanjosea sp. nov. and S. tenoriosa sp. nov. A key for distinguishing the genera Megalochus and Stethantyx, and a key to 22 Costa Rican species of Stethantyx are provided.

First record of the genus Zaglyptus Förster (Hymenoptera: Ichneumonidae: Pimplinae) from Vietnam, with description of one new species.

The ichneumonid wasp genus Zaglyptus Förster, 1868 is reported for the first time from Vietnam, with three species found in the country. One new species, Zaglyptus guptai sp. nov., is described based on material collected in Chu Yang Sin NP, Dak Lak Province. Two other species, Z. glaber Gupta and Z. nigrolineatus, Gupta are recorded as new for the country. In addition, the subspecies Z glaber singaporensis Gupta is synonymised with the nominate subspecies.

Revision of the New World species of Erythrodolius (Hymenoptera: Ichneumonidae: Sisyrostolinae), with a key to the world species.

The genus Erythrodolius previously comprised ten species of ichneumonids: nine from Madagascar and one from Costa Rica. The current study revises the New World species of Erythrodolius including descriptions of three new species from Central America which brings the world total to 13 species: E. incompletus sp. n., E. luteus sp. n. and E. tenebrosus sp. n. A key to the world species is provided. Justification for the preference of the subfamily name Sisyrostolinae instead of Brachyscleromatinae is provided.

The genome sequence of the ichneumon wasp Buathra laborator (Thunberg, 1822).

We present a genome assembly from an individual Buathra laborator (Arthropoda; Insecta; Hymenoptera; Ichneumonidae). The genome sequence is 330 megabases in span. Over 60% of the assembly is scaffolded into 11 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 35.8 kilobases in length.

The genome sequence of the Four-dotted Footman, Cybosia mesomella (Linnaeus, 1758).

We present a genome assembly from an individual male Cybosia mesomella (the Four-dotted Footman; Arthropoda; Insecta; Lepidoptera; Erebidae). The genome sequence is 948 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, with the Z sex chromosome assembled. The mitochondrial genome has also been assembled and is 15.4 kilobases in length.

The genome sequence of the Small Ranunculus, Hecatera dysodea (Denis & Schiffermüller, 1775).

We present a genome assembly from an individual female Hecatera dysodea (the Small Ranunculus; Arthropoda; Insecta; Lepidoptera; Noctuidae). The genome sequence is 640.9 megabases in span. Most of the assembly is scaffolded into 32 chromosomal pseudomolecules, including the Z and W sex chromosomes. The mitochondrial genome has also been assembled and is 15.4 kilobases in length. Gene annotation of this assembly on Ensembl has identified 12,213 protein coding genes.

The genome sequence of Clancy's Rustic, Caradrina kadenii (Freyer, 1836).

We present a genome assembly from an individual male Caradrina kadenii (Clancy's Rustic; Arthropoda; Insecta; Lepidoptera; Noctuidae). The genome sequence is 426.0 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.4 kilobases in length.

The genome sequence of the Grey Dagger, Acronicta psi (Linnaeus, 1758).

We present a genome assembly from an individual male Acronicta psi (the Grey Dagger; Arthropoda; Insecta; Lepidoptera; Noctuidae). The genome sequence is 405 megabases in span. The whole assembly is scaffolded into 31 chromosomal pseudomolecules, including the assembled Z sex chromosome. The mitochondrial genome has also been assembled and is 15.4 kilobases long.

The genome sequence of the Festoon, Apoda limacodes (Hufnagel, 1766).

We present a genome assembly from an individual male Apoda limacodes (the Festoon; Arthropoda; Insecta; Lepidoptera; Limacodidae). The genome sequence is 800 megabases in span. Most of the assembly is scaffolded into 25 chromosomal pseudomolecules, including the assembled Z sex chromosome. The mitochondrial genome has also been assembled and is 15.4 kilobases in length.

The genome sequence of an ichneumon wasp, Ophion slaviceki (Kriechbaumer, 1892).

We present a genome assembly from an individual female Ophion slaviceki (an ichneumon wasp; Arthropoda; Insecta; Hymenoptera; Ichneumonidae). The genome sequence is 654.2 megabases in span. Most of the assembly is scaffolded into 13 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 16.19 kilobases in length. Gene annotation of this assembly on Ensembl identified 19,399 protein coding genes.