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.].

Threats from the air: Damselfly predation on diverse prey taxa.

To understand the diversity and strength of predation in natural communities, researchers must quantify the total amount of prey species in the diet of predators. Metabarcoding approaches have allowed widespread characterization of predator diets with high taxonomic resolution. To determine the wider impacts of predators, researchers should combine DNA techniques with estimates of population size of predators using mark-release-recapture (MRR) methods, and with accurate metrics of food consumption by individuals. Herein, we estimate the scale of predation exerted by four damselfly species on diverse prey taxa within a well-defined 12-ha study area, resolving the prey species of individual damselflies, to what extent the diets of predatory species overlap, and which fraction of the main prey populations are consumed. We identify the taxonomic composition of diets using DNA metabarcoding and quantify damselfly population sizes by MRR. We also use predator-specific estimates of consumption rates, and independent data on prey emergence rates to estimate the collective predation pressure summed over all prey taxa and specific to their main prey (non-biting midges or chironomids) of the four damselfly species. The four damselfly species collectively consumed a prey mass equivalent to roughly 870 (95% CL 410-1,800) g, over 2 months. Each individual consumed 29%-66% (95% CL 9.4-123) of its body weight during its relatively short life span (2.1-4.7 days; 95% CL 0.74-7.9) in the focal population. This predation pressure was widely distributed across the local invertebrate prey community, including 4 classes, 19 orders and c. 140 genera. Different predator species showed extensive overlap in diets, with an average of 30% of prey shared by at least two predator species. Of the available prey individuals in the widely consumed family Chironomidae, only a relatively small proportion (0.76%; 95% CL 0.35%-1.61%) were consumed. Our synthesis of population sizes, per-capita consumption rates and taxonomic distribution of diets identifies damselflies as a comparatively minor predator group of aerial insects. As the next step, we should add estimates of predation by larger odonate species, and experimental removal of odonates, thereby establishing the full impact of odonate predation on prey communities.

Biodiversity assessments in the 21st century: the potential of insect traps to complement environmental samples for estimating eukaryotic and prokaryotic diversity using high-throughput DNA metabarcoding 1.

The rapid loss of biodiversity, coupled with difficulties in species identification, call for innovative approaches to assess biodiversity. Insects make up a substantial proportion of extant diversity and play fundamental roles in any given ecosystem. To complement morphological species identification, new techniques such as metabarcoding make it possible to quantify insect diversity and insect-ecosystem interactions through DNA sequencing. Here we examine the potential of bulk insect samples (i.e., containing many non-sorted specimens) to assess prokaryote and eukaryote biodiversity and to complement the taxonomic coverage of soil samples. We sampled 25 sites on three continents and in various ecosystems, collecting insects with SLAM traps (Brazil) and Malaise traps (South Africa and Sweden). We then compared our diversity estimates with the results obtained with biodiversity data from soil samples from the same localities. We found a largely different taxonomic composition between the soil and insect samples, testifying to the potential of bulk insect samples to complement soil samples. Finally, we found that non-destructive DNA extraction protocols, which preserve insect specimens for morphological studies, constitute a promising choice for cost-effective biodiversity assessments. We propose that the sampling and sequencing of insect samples should become a standard complement for biodiversity studies based on environmental DNA.

What you need is what you eat? Prey selection by the bat Myotis daubentonii.

Optimal foraging theory predicts that predators are selective when faced with abundant prey, but become less picky when prey gets sparse. Insectivorous bats in temperate regions are faced with the challenge of building up fat reserves vital for hibernation during a period of decreasing arthropod abundances. According to optimal foraging theory, prehibernating bats should adopt a less selective feeding behavior--yet empirical studies have revealed many apparently generalized species to be composed of specialist individuals. Targeting the diet of the bat Myotis daubentonii, we used a combination of molecular techniques to test for seasonal changes in prey selectivity and individual-level variation in prey preferences. DNA metabarcoding was used to characterize both the prey contents of bat droppings and the insect community available as prey. To test for dietary differences among M. daubentonii individuals, we used ten microsatellite loci to assign droppings to individual bats. The comparison between consumed and available prey revealed a preference for certain prey items regardless of availability. Nonbiting midges (Chironomidae) remained the most highly consumed prey at all times, despite a significant increase in the availability of black flies (Simuliidae) towards the end of the season. The bats sampled showed no evidence of individual specialization in dietary preferences. Overall, our approach offers little support for optimal foraging theory. Thus, it shows how novel combinations of genetic markers can be used to test general theory, targeting patterns at both the level of prey communities and individual predators.

Spider silk felting-functional morphology of the ovipositor tip of Clistopyga sp. (Ichneumonidae) reveals a novel use of the hymenopteran ovipositor.

Apical serrations of the hymenopteran ovipositor have been widely postulated to originally constitute adaptations for cutting through hard substrates. Simplifications of the ovipositor tip have occurred in several ichneumonid wasp genera associated with spiders. Despite such reduction in Clistopyga (Hymenoptera, Ichneumonidae), the ovipositor still possesses some apical serrations. Through the first detailed study, we believe, on the behaviour of an ovipositing Clistopyga species, we show that it can alter its ovipositor for different purposes and that the primary function of the apical serrations is clinging to its spider host as the spider attempts to escape. Intriguingly, we also discover a hitherto undocumented adaptation for the hymenopteran ovipositor. The female wasp seals openings in the silken spider nest by using its ovipositor on the silk in a highly sophisticated way that is comparable to how humans entangle wool by needle felting. By studying the ovipositor morphology through a scanning electron microscope, we elucidate how this works, and we hypothesize that by closing the nest the female wasp protects its developing kin.

Tersilochinae of Western Amazonia (Hymenoptera: Ichneumonidae). Genus Stethantyx Townes, part 2.

In this paper we describe four new species of Stethantyx Townes (Ichneumonidae: Tersilochinae) from Ecuador and Peru characterized by the fore wing with first and second abscissae of radius meeting at right angle: S. erwini Khalaim & Sääksjärvi, sp. nov., S. radiata Khalaim & Sääksjärvi, sp. nov., S. rufispa Khalaim & Bordera, sp. nov. and S. undulata Khalaim & Sääksjärvi, sp. nov. Second part of the key to species of Stethantyx occurring in Western Amazonia is given. Additionally, S. altamira Khalaim & Broad and S. aprica Khalaim & Broad are recorded from South America for the first time, and new data on distribution of S. alajuela Khalaim & Broad, S. amazonica Khalaim & Sääksjärvi, S. heredia Kha-laim & Broad, S. orellana Khalaim & Sääksjärvi, S. sinuata Khalaim & Sääksjärvi and S. trepida Khalaim & Sääksjärvi in South America are provided. Male of S. orellana is recorded for the first time.

Three new Afrotropical species of Tersilochinae (Hymenoptera: Ichneumonidae) from the Kibale National Park, Uganda.

Seven species of Tersilochinae (Hymenoptera: Ichneumonidae) have been found from Uganda in Equatorial Africa: Allophrys budongoana Khalaim, Diaparsis interstitialis Khalaim, D. kanyawara sp. nov., D. mostovskii Khalaim, D. sinuator sp. nov., D. umbrosa sp. nov. and Tersilochus moestus Holmgren. Two species of Diaparsis, described in this paper, possess a white banded flagellum, and a key to the group of four Afrotropical species having a white-banded flagellum is provided. Tersilochus moestus Holmgren, previously known only from a single female from South Africa, is recorded from the Kibale National Park, Uganda. Antennae and ovipositor of this species, broken in the type specimen, are described for the first time. 

First record of Poemeniinae (Hymenoptera, Ichneumonidae) from Peru, with description of a new species and a key to the world species of Ganodes Townes.

The subfamily Poemeniinae (Hymenoptera, Ichneumonidae) is reported for the first time from Peru. We describe and illustrate a new species, Ganodes atayupanquii sp. n. Castillo & Sääksjärvi, which was collected from the Peruvian Andes at 1500 m. A key to the species of Ganodes Townes and new distribution records of G. wahli Díaz and G. matai Gauld are provided.

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. 

Tersilochinae of Western Amazonia (Hymenoptera: Ichneumonidae). Genus Stethantyx Townes, part 1.

Sixteen species of the genus Stethantyx Townes having first and second sections of radius meeting at obtuse angle are recorded from Peru and Ecuador in Western Amazonia. Ten species, S. amazonica Khalaim & Sääksjärvi, sp. nov., S. aurantia Khalaim & Sääksjärvi, sp. nov., S. juninensis Khalaim & Bordera, sp. nov., S. loretosa Khalaim & Sääksjärvi, sp. nov., S. neopropodeator Khalaim & Sääksjärvi, sp. nov., S. orellana Khalaim & Sääksjärvi, sp. nov., S. sinuata Khalaim & Sääksjärvi, sp. nov., S. tiputinia Khalaim & Sääksjärvi, sp. nov., S. trepida Khalaim & Sääksjärvi, sp. nov. and S. voluptaria Khalaim & Sääksjärvi, sp. nov., are described as new. Six species, previously known only from Costa Rica,           S. alajuela Khalaim & Broad, S. heredia Khalaim & Broad, S. orosia Khalaim & Broad, S. propodeator Khalaim & Broad, S. puntarenasa Khalaim & Broad and S. sanjosea Khalaim & Broad, are recorded from South America for the first time. A partial key to Western Amazonian species of Stethantyx is given.

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.

Capitojoppa, a new genus of Ichneumoninae (Hymenoptera, Ichneumonidae) from Peruvian Amazonia.

A new monotypic genus of ichneumonine parasitoid wasps (Hymenoptera, Ichneumonidae, Ichneumoninae) is described from Peru; Capitojoppagen. nov. is described to accommodate Capitojoppaamazonicasp. nov. The new genus is morphologically very distinctive and can be easily separated from all known ichneumonine genera. By describing Capitojoppa from the lowland rain forests of Peru, we aim to draw attention to the considerable diversity and morphological variation of the Amazonian ichneumonine fauna.

Crowdsourced tick observation data from across 60 years reveals major increases and northwards shifts in tick contact areas in Finland.

There is mounting evidence of increases in tick (Acari: Ixodidae) contacts in Finland during the past few decades, highlighted by increases in the incidence of Lyme borreliosis and tick-borne encephalitis (TBE). While nationwide field studies to map distributions of ticks are not feasible, crowdsourcing provides a comprehensive method with which to assess large-scale changes in tick contact areas. Here, we assess changes in tick contact areas in Finland between 1958 and 2021 using three different nationwide crowdsourced data sets. The data revealed vast increases in tick contact areas, with ticks estimated to be contacted locally approximately 400 km further north in western and approximately 100 km further north in eastern Finland in 2021 than 1958. Tick contact rates appeared to be highest along the coastline and on the shores of large lakes, possibly indicating higher tick abundance therein. In general, tick observations per inhabitant increased from 2015 to 2021. Tick contact areas have expanded in Finland over the past 60 years. It appears that taiga ticks (Ixodes persulcatus) are behind most of the northwards shifts in tick contact areas, with Ixodes ricinus contributing mostly to new contact areas in the south. While ticks are now present in most of Finland, there are still areas where tick abundance is low and/or establishment not possible, mainly in northern Finland.

Variation in a Darwin Wasp (Hymenoptera: Ichneumonidae) Community along an Elevation Gradient in a Tropical Biodiversity Hotspot: Implications for Ecology and Conservation.

Understanding how biodiversity varies from place to place is a fundamental goal of ecology and an important tool for halting biodiversity loss. Parasitic wasps (Hymenoptera) are a diverse and functionally important animal group, but spatial variation in their diversity is poorly understood. We survey a community of parasitic wasps (Ichneumonidae: Pimplinae) using Malaise traps up a mountain in the Brazilian Atlantic Rainforest, and relate the catch to biotic and abiotic habitat characteristics. We find high species richness compared with previous similar studies, with abundance, richness, and diversity peaking at low to intermediate elevation. There is a marked change in community composition with elevation. Habitat factors strongly correlated with elevation also strongly predict changes in the pimpline community, including temperature as well as the density of bamboo, lianas, epiphytes, small trees, and herbs. These results identify several possible surrogates of pimpline communities in tropical forests, which could be used as a tool in conservation. They also contribute to the growing evidence for a typical latitudinal gradient in ichneumonid species richness, and suggest that low to medium elevations in tropical regions will sometimes conserve the greatest number of species locally, but to conserve maximal biodiversity, a wider range of elevations should also be targeted.

Unprecedented ichneumonid parasitoid wasp diversity in tropical forests.

The megadiverse parasitoid wasp family Ichneumonidae (Hymenoptera) is classically considered an exception to the extensively studied latitudinal diversity gradient: the majority of ichneumonid species are described from temperate regions. The gradient has been hypothesized to be dependent on the biology of the wasps, but recently questions of sampling and description biases have been raised. Here, we show with primary data that the species richness of Ichneumonidae is markedly underestimated in tropical areas and that latitudinal diversity patterns in the family remain uncharacterized. We discovered a startling 177 likely undescribed orthocentrine species with relatively low sampling effort in the forests of Central America and Amazonian Ecuador, over three times the previously known orthocentrine diversity in the world's tropics. Species accumulation curves reveal that we are just beginning to unveil the true extent of tropical orthocentrine diversity. We also found evidence for cryptic species; our DNA analysis revealed additional species not easily distinguishable using morphological characteristics. The difficulty in establishing species richness patterns of Ichneumonidae probably follows from the relative lack of taxonomic expertise and the low density of ichneumonid species throughout the landscape.

Cryptic biodiversity of tropical hesperiid caterpillar-attacking parasitoid wasps: three new species of Creagrura Townes (Hymenoptera, Ichneumonidae, Cremastinae) from Costa Rica and Perú.

Background: We describe three new species of the previously monotypic genus Creagrura Townes from Central and South America: C.alejandromasisi sp. n. and C.rogerblancoi sp. n. from Costa Rica and C.allpahuaya sp. n. from Peru, all of which emphasise the unknown parasitoid insect diversity yet to be revealed in the tropics. New information: Host relationships of the two Costa Rican species are described in detail. In addition, it is inferred that the Creagrura wasps find and oviposit in the caterpillar when it is exposed at night, rather than when it is concealed during daylight hours.

A review of the spider-attacking Polysphinctadizardi species-group (Hymenoptera, Ichneumonidae, Pimplinae), with descriptions of seven new species from South America.

The Neotropical Polysphinctadizardi species-group is revised. We describe seven new species from South America: P.bonita sp. nov., P.cosnipata sp. nov., P.inca sp. nov., P.macroepomia sp. nov., P.organensis sp. nov., P.pichincha sp. nov., and P.teresa sp. nov. In addition, we provide a diagnosis and an identification key to all species of the group.

Pimpla Fabricius, 1804 (Ichneumonidae, Pimplinae) from Uruguay: a replacement name, new records, and an identification key to the species.

We report new faunistic records of Pimpla Fabricius, 1804 from Uruguay. The following species are reported from the country for the first time: P. albomarginata Cameron, 1846, P. caerulea Brullé, 1846, P. perssoni Gauld, 1991, and P. semirufa Brullé, 1846. In addition, we propose a replacement name for Pimpla rufipes Brullé, 1846 and provide diagnosis, digital images, and an identification key for all the Pimpla species known to occur in Uruguay.

Review of the New World genus Acrotaphus Townes, 1960 (Hymenoptera: Ichneumonidae: Pimplinae), with descriptions of fifteen new species.

Acrotaphus Townes, 1960 is a moderately large New World genus of spider attacking parasitoid wasps. Previously, it comprised 11 species. The present study aims to review the genus, and includes descriptions of 15 new species: A. amajari sp. n., A. amazonicus sp. n., A. bodoquenaensis sp. n., A. cuzconus sp. n., A. dolichopus sp. n., A. homeofranklini sp. n., A. jackiechani sp. n., A. kourou sp. n., A. micrus sp. n., A. monotaenius sp. n., A. nambilloensis sp. n., A. pseudoamazonicus sp. n., A. pseudomexicanus sp. n., A. venezuelanus sp. n. and A. zampieronae sp. n.. In addition, we present new characters for the study of the genus and describe the male genitalia for the first time. An illustrated key and maps to the species of the genus are provided. Acrotaphus franklini Gauld, 1991 and A. pseudoamazonicus sp. n. were recorded from the nests of Trypoxylon (Trypargilum) lactitarse Saussure, 1867 (Hymenoptera: Crabronidae).