Phylogenomic analysis of Stylops reveals the evolutionary history of a Holarctic Strepsiptera radiation parasitizing wild bees.

Holarctic Stylops is the largest genus of the enigmatic insect order Strepsiptera, twisted winged parasites. Members of Stylops are obligate endoparasites of Andrena mining bees and exhibit extreme sexual dimorphism typical of Strepsiptera. So far, molecular studies on Stylops have focused on questions on species delimitation. Here, we utilize the power of whole genome sequencing to infer the phylogeny of this morphologically challenging genus from thousands of loci. We use a species tree method, concatenated maximum likelihood analysis and Bayesian analysis with a relaxed clock model to reconstruct the phylogeny of 46 Stylops species, estimate divergence times, evaluate topological consistency across methods and infer the root position. Furthermore, the biogeographical history and coevolutionary patterns with host species are assessed. All methods recovered a well resolved topology with close to all nodes maximally supported and only a handful of minor topological variations. Based on the result, we find that included species can be divided into 12 species groups, seven of them including only Palaearctic species, three Nearctic and two were geographically mixed. We find a strongly supported root position between a clade formed by the spreta, thwaitesi and gwynanae species groups and the remaining species and that the sister group of Stylops is Eurystylops or Eurystylops + Kinzelbachus. Our results indicate that Stylops originated in the Western Palaearctic or Western Palaearctic and Nearctic in the early Neogene or late Paleogene, with four independent dispersal events to the Nearctic. Cophylogenetic analyses indicate that the diversification of Stylops has been shaped by both significant coevolution with the mining bee hosts and host-shifting. The well resolved and strongly supported phylogeny will provide a valuable phylogenetic basis for further studies into the fascinating world of Strepsipterans.

Myocardial External Efficiency in Asymptomatic Severe Primary Mitral Regurgitation Using 11C-Acetate PET.

Subjects with asymptomatic moderate-to-severe or severe primary mitral regurgitation are closely observed for signs of progression or symptoms requiring surgical intervention. The role of myocardial metabolic function in progression of mitral regurgitation is poorly understood. We used 11C-acetate PET to noninvasively measure myocardial mechanical external efficiency (MEE), which is the energetic ratio of external cardiac work and left ventricular (LV) oxygen consumption. Methods: Forty-seven patients in surveillance with mitral regurgitation and no or minimal symptoms prospectively underwent PET, echocardiography, and cardiac MRI on the same day. PET was used to simultaneously measure cardiac output, LV mass, and oxygen consumption to establish MEE. PET findings were compared between patients and healthy volunteers (n = 9). MEE and standard imaging indicators of regurgitation severity, LV volumes, and function were studied as predictors of time to surgical intervention. Patients were followed a median of 3.0 y (interquartile range, 2.0-3.8 y), and the endpoint was reached in 22 subjects (47%). Results: MEE in patients reaching the endpoint (23.8% ± 5.0%) was lower than in censored patients (28.5% ± 4.5%, P = 0.002) or healthy volunteers (30.1% ± 4.9%, P = 0.001). MEE with a cutoff lower than 25.7% was significantly associated with the outcome (hazard ratio, 7.5; 95% CI, 2.7-20.6; P < 0.0001) and retained independent significance when compared with standard imaging parameters. Conclusion: MEE independently predicted time to progression requiring valve surgery in patients with asymptomatic moderate-to-severe or severe primary mitral regurgitation. The study suggests that inefficient myocardial oxidative metabolism precedes clinically observed progression in mitral regurgitation.

Morphology of the larvae of Rhantaticus congestus (Klug, 1833) and phylogenetic comparison with other known Aciliini (Coleoptera: Dytiscidae: Dytiscinae).

We describe the second- and third instar larvae of the diving beetle Rhantaticus congestus (Klug, 1833), including detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, terminal abdominal segment and urogomphi in order to discover useful characters for distinguishing Rhantaticus Sharp, 1882 larvae from those of other known Aciliini (Coleoptera: Dytiscidae: Dytiscinae). A parsimony analysis based on 94 larval characteristics of nine Aciliini species in five genera (Acilius Leach, 1817, Graphoderus Dejean, 1833, Rhantaticus, Sandracottus Sharp, 1882, Thermonectus Dejean, 1833) was conducted using the program TNT. Rhantaticus shares with all these genera several larval character states which support its inclusion in the Aciliini. Whereas Rhantaticus larva stands out from other known genera by several unique character states, our parsimony analysis did not recover any clear phylogenetic position of this genus within the Aciliini.

Remaining forests on the Central Highlands of Madagascar-Endemic and endangered aquatic beetle fauna uncovered.

Madagascar is known for its high endemism and as many as 90% of this unique diversity are forest-dwellers. Unfortunately, the forest cover of Madagascar is decreasing at an alarming rate. This decrease can also affect aquatic insects, but our knowledge on aquatic insect diversity and distribution on Madagascar are limited. Although the eastern rainforests are considered the most diverse, the Central Highlands of Madagascar also harbors unique microendemic fauna but has been less studied. Here, we analyze the aquatic Adephaga beetle fauna of three remaining protected forests of the Central Highlands. Diversity, abundance, and uniqueness are compared between and within natural forests and surrounding grasslands. At least 15 undescribed species were found, highlighting the Central Highlands as an important area for endemism. The natural forests and the surrounding grasslands differed significantly in species assemblages. Interestingly, the three remaining forests differed in their assemblages with the geographically more distant Manjakatompo Ankaratra having the most unique fauna but also the highest altitude span. By contrast, the species composition was similar between the peripheral zones of each of the three remaining forests. The similarity of the fauna in the peripheral open habitats illustrates how some local forest endemics are replaced with widespread generalists in degraded habitats. Our study shows that the remaining forests of the Central Highlands of Madagascar are important refuges of unique fauna at high risk of extinction.

The Naucoridae (Heteroptera: Nepomorpha) of Madagascar, with revisions of Temnocoris and Tsingala (Laccocorinae).

The island nation of Madagascar was surveyed extensively through a series of expeditions to determine the fauna of Naucoridae. Previously, 17 species in four genera had been reported from the country. All taxa previously recorded from Madagascar were re-collected, with the exception of three species, Macrocoris flavicollis Signoret, Temnocoris starmuhlneri Poisson, and Tsingala nossibeanus (Bergroth). Macrocoris flavicollis is removed from the list of species occurring in Madagascar. Within Laccocorini (Laccocorinae), a new genus, Gonioathrix n.gen. is described; Temnocoris and Tsingala are revised; three new species are described in Temnocoris (T. leachi n.sp., T. montandoni n.sp., T. poissoni n.sp.) and four in Tsingala (T. angulata n.sp., T. latiforma n.sp., T. spatulata n.sp., T. trilobata n.sp.). Lectotypes are designated for Afronaucoris madagascariensis (Montandon), Tsingala humeralis (Signoret), and T. naucoroides (Montandon). In Macrocorinae, a new species of Macrocoris, M. namorona n.sp., from Ranomafana National Park is described. These taxonomic actions bring the total for the country to five genera and 25 species. Distributions, habitat associations, and a key to the species are presented.

A 33-year follow-up after valvular surgery for carcinoid heart disease.

AIMS: Valvular surgery has improved long-term prognosis in severe carcinoid heart disease (CaHD). Experience is limited and uncertainty remains about predictors for survival and strategy regarding single vs. double-valve surgery. The aim was to review survival and echocardiographic findings after valvular surgery for CaHD at our institution. METHODS AND RESULTS: Between 1986 and 2019, 60 consecutive patients, median age 64 years, underwent valve surgery for severe CaHD. Operations involved combined tricuspid valve replacement (TVR) and pulmonary valve replacement (PVR) in 42 cases, and TVR-only or TVR with pulmonary valvotomy (no PVR) in 18 patients. All implanted valves were bioprosthetic. Preoperative echocardiography, creatinine, NT-pro-brain natriuretic peptide (NT-pro-BNP), and 24-h urinary 5-hydroxyindoleacetic acid (5-HIAA) were obtained. 30-Day mortality was 12% (n=7), and 8% for the most recent decade 2010-2019. Median survival was 2.2 years and maximum survival 21 years. Patients undergoing combined TVR and PVR had significantly higher survival compared with operations without PVR (median 3.0 vs. 0.9 years, P = 0.02). Preoperative levels of NT-pro-BNP and 5-HIAA in the top quartile predicted poor survival. On preoperative echocardiograms, pulmonary regurgitation was severe in 51% and indeterminate in 17%. Postoperative echocardiography confirmed relatively good durability of bioprostheses, relative to the patients' limited oncological life expectancy. CONCLUSION: Valvular surgery in CaHD has an acceptable perioperative risk. Survival for combined TVR and PVR was significantly higher compared with operations without PVR. Bioprosthetic valve replacement appears to have adequate durability. Preoperative echocardiography may underestimate pulmonary pathology. Combined TVR and PVR should be considered in most patients.

Larval morphology of the Madagascan endemic diving beetle genus Hovahydrus Biström, 1982 (Coleoptera: Dytiscidae) and phylogenetic comparison with other known Hyphydrini.

We describe for the first time the instar III larva of the diving beetle genus Hovahydrus Biström, 1982, based on H. praetextus (Guignot, 1951) and a new species yet to be described (identified here as Hovahydrus sp. near H. minutissimus (Régimbart, 1903)). We include detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi in order to discover useful characters for distinguishing Hovahydrus larvae from those of other known Hyphydrini (Coleoptera: Dytiscidae, Hydroporinae). A provisional parsimony analysis based on larval characteristics of 11 Hyphydrini species in eight genera was conducted using the program TNT. Larval morphology supports a close relationship between Hovahydrus, Hyphydrus Illiger, 1802, and the endemic South Africa genera Andex Sharp, 1882, Coelhydrus Sharp, 1882, Darwinhydrus Sharp, 1882 and Primospes Sharp, 1882.

Spatio-temporal variation in water beetle assemblages across temperate freshwater ecosystems.

Ecological communities are structured by several mechanisms, including temporal, spatial and environmental factors. However, the simultaneous effects of these factors have rarely been studied. Here, we investigated their role on water beetle assemblages sampled over a period of 18 years. Water beetles were sampled in the spring of each year in lotic and lentic water bodies from mainland region of Kalmar and Öland Island in southeastern Sweden. We assessed how past assemblage structure, environmental factors and spatial variables correlated with current assemblage structure using a variation partitioning approach. We also tested for correlates of temporal beta diversity of water beetle assemblages with multiple regressions. We found that past water beetle assemblage structure explained current water beetle assemblage structure better than the environmental and spatial correlates. We also observed that temporal beta diversity of water beetle assemblages was mainly due to species gain rather than to species loss. Finally, environmental variables (e.g., hydroperiod, habitat size and hydrology) and timespan between sampling events explained part of temporal beta diversity and contribution of species loss to total assemblage dissimilarity variation. Despite the fact that most variation remained unexplained, we found that ecological factors that have been thought to be important for water beetle richness and abundance in past studies (e.g. water body size, water permanence, shore slope, and whether the water body is lentic or lotic) were also correlated to temporal beta diversity. From a conservation point of view, our study suggest that temporal variability of assemblage structure should be included in biological monitoring because of its potential to predict current assemblage structure.

Cardiac Imaging in Carcinoid Heart Disease.

Carcinoid disease is caused by neuroendocrine tumors, most often located in the gut, and leads in approximately 20% of cases to specific, severe heart disease, most prominently affecting right-sided valves. If cardiac disease occurs, it determines the patient's prognosis more than local growth of the tumor. Surgical treatment of carcinoid-induced valve disease has been found to improve survival in observational studies. Cardiac imaging is crucial for both diagnosis and management of carcinoid heart disease; in the past, imaging was accomplished largely by echocardiography, but more recently, imaging for carcinoid heart disease has increasingly become multimodal and warrants awareness of the particular diagnostic challenges of this disease. This paper reviews the pathophysiology and manifestations of carcinoid heart disease in light of the different imaging modalities.

DNA Barcoding and geographical scale effect: The problems of undersampling genetic diversity hotspots.

DNA barcoding identification needs a good characterization of intraspecific genetic divergence to establish the limits between species. Yet, the number of barcodes per species is many times low and geographically restricted. A poor coverage of the species distribution range may hamper identification, especially when undersampled areas host genetically distinct lineages. If so, the genetic distance between some query sequences and reference barcodes may exceed the maximum intraspecific threshold for unequivocal species assignation. Taking a group of Quercus herbivores (moths) in Europe as model system, we found that the number of DNA barcodes from southern Europe is proportionally very low in the Barcoding of Life Data Systems. This geographical bias complicates the identification of southern query sequences, due to their high intraspecific genetic distance with respect to barcodes from higher latitudes. Pairwise intraspecific genetic divergence increased along with spatial distance, but was higher when at least one of the sampling sites was in southern Europe. Accordingly, GMYC (General Mixed Yule Coalescent) single-threshold model retrieved clusters constituted exclusively by Iberian haplotypes, some of which could correspond to cryptic species. The number of putative species retrieved was more reliable than that of multiple-threshold GMYC but very similar to results from ABGD and jMOTU. Our results support GMYC as a key resource for species delimitation within poorly inventoried biogeographic regions in Europe, where historical factors (e.g., glaciations) have promoted genetic diversity and singularity. Future European DNA barcoding initiatives should be preferentially performed along latitudinal gradients, with special focus on southern peninsulas.

Taxonomic revision of the Afrotropical Agabus raffrayi species group with the description of four new species (Coleoptera, Dytiscidae).

We revise the Afrotropical Agabus raffrayi species group, motivated by the discovery of new diversity in Kenya and South Africa. Whilst Agabus is mainly a holarctic genus, the Agabus raffrayi group is restricted to high altitude regions of eastern Africa and temperate parts of South Africa, from where we describe the southernmost Agabus in the world. The following new species are introduced: Agabus anguluverpus sp. nov. from Mount Kenya in central Kenya, Agabus austellus sp. nov. a widespread species in South Africa, Agabus riberae sp. nov. from the Kamiesberg and northeastern Cederberg ranges in the Northern and Western Cape Provinces of South Africa and Agabus agulhas sp. nov. from the Agulhas Plain, Western Cape Province, South Africa. We provide a distribution map, a determination key for males, quantitative measurements of diagnostic characters, habitus photos and detailed photos of male genitalia for all described species in the group, as well as images of diagnostic characters and habitats. The presence or absence of an elongated section between the subapical broadening and the base of the apical and subapical teeth of the male aedeagus is a useful novel character, first revealed by our study. In contrast with the most recent revision of Afrotropical Agabus, we show that Agabus ruwenzoricus Guignot, 1936 is restricted to eastern Africa; South African records of this species having been based on misidentifications, no species of the group being common to southern and eastern Africa. We speculate that the raffrayi group may display phylogenetic niche conservatism, being restricted, as an originally temperate taxon, to higher elevations in tropical eastern Africa, but occurring at lower altitudes in temperate South Africa.

Species delimitation in the cyanolichen genus Rostania.

BACKGROUND: In this study, we investigate species limits in the cyanobacterial lichen genus Rostania (Collemataceae, Peltigerales, Lecanoromycetes). Four molecular markers (mtSSU rDNA, ß-tubulin, MCM7, RPB2) were sequenced and analysed with two coalescent-based species delimitation methods: the Generalized Mixed Yule Coalescent model (GMYC) and a Bayesian species delimitation method (BPP) using a multispecies coalescence model (MSC), the latter with or without an a priori defined guide tree. RESULTS: Species delimitation analyses indicate the presence of eight strongly supported candidate species. Conclusive correlation between morphological/ecological characters and genetic delimitation could be found for six of these. Of the two additional candidate species, one is represented by a single sterile specimen and the other currently lacks morphological or ecological supporting evidence. CONCLUSIONS: We conclude that Rostania includes a minimum of six species: R. ceranisca, R. multipunctata, R. occultata 1, R. occultata 2, R. occultata 3, and R. occultata 4,5,6. Three distinct Nostoc morphotypes occur in Rostania, and there is substantial correlation between these morphotypes and Rostania thallus morphology.

Completing Linnaeus's inventory of the Swedish insect fauna: Only 5,000 species left?

Despite more than 250 years of taxonomic research, we still have only a vague idea about the true size and composition of the faunas and floras of the planet. Many biodiversity inventories provide limited insight because they focus on a small taxonomic subsample or a tiny geographic area. Here, we report on the size and composition of the Swedish insect fauna, thought to represent roughly half of the diversity of multicellular life in one of the largest European countries. Our results are based on more than a decade of data from the Swedish Taxonomy Initiative and its massive inventory of the country's insect fauna, the Swedish Malaise Trap Project The fauna is considered one of the best known in the world, but the initiative has nevertheless revealed a surprising amount of hidden diversity: more than 3,000 new species (301 new to science) have been documented so far. Here, we use three independent methods to analyze the true size and composition of the fauna at the family or subfamily level: (1) assessments by experts who have been working on the most poorly known groups in the fauna; (2) estimates based on the proportion of new species discovered in the Malaise trap inventory; and (3) extrapolations based on species abundance and incidence data from the inventory. For the last method, we develop a new estimator, the combined non-parametric estimator, which we show is less sensitive to poor coverage of the species pool than other popular estimators. The three methods converge on similar estimates of the size and composition of the fauna, suggesting that it comprises around 33,000 species. Of those, 8,600 (26%) were unknown at the start of the inventory and 5,000 (15%) still await discovery. We analyze the taxonomic and ecological composition of the estimated fauna, and show that most of the new species belong to Hymenoptera and Diptera groups that are decomposers or parasitoids. Thus, current knowledge of the Swedish insect fauna is strongly biased taxonomically and ecologically, and we show that similar but even stronger biases have distorted our understanding of the fauna in the past. We analyze latitudinal gradients in the size and composition of known European insect faunas and show that several of the patterns contradict the Swedish data, presumably due to similar knowledge biases. Addressing these biases is critical in understanding insect biomes and the ecosystem services they provide. Our results emphasize the need to broaden the taxonomic scope of current insect monitoring efforts, a task that is all the more urgent as recent studies indicate a possible worldwide decline in insect faunas.

New Myxophagan water beetles from Madagascar (Coleoptera: Torridincolidae, Hydroscaphidae).

Myxophagan water beetles from Madagascar are comprehensively revised. Holotypes of the two previously known species are re-described and illustrated. Six new species of Incoltorrida Steffan and one new species of Hydroscapha LeConte are described and illustrated. The larvae of Incoltorrida quintacostata are illustrated and discussed. The presence of peritrich ciliates of the genus Platycola Kent on specimens of Incoltorrida madagassica Steffan is discussed and illustrated. Habitus, habitats, and male genitalia are illustrated, and distributions are mapped. The following new species are described (type localities parenthetic): Incoltorrida benesculpta n. sp. (Fianarantsoa, 3.2km S Ambohimanjaka); I. galoko n. sp. (Antsiranana, Diana, Ambilobe, Antsaba, Galoko mountains ); I. magna n. sp. (Antsiranana, Diana, Ambilobe, Antsaba, Galoko mountains); I. marojejy n. sp. (Antsiranana, Sava, Marojejy National Park); I. quintacostata n. sp. (Fianarantsoa, 3.5km N Ivato); I. zahamena n. sp. (Toamasina, Alaotra-Mangoro, Zahamena National Park); Hydroscapha andringitra n. sp. (Fianarantsoa, Ambilavao, Sendrisoa, approx. 10km N of Andringitra National Park).

Taxonomic revision of the genus Copelatus of Madagascar (Coleoptera, Dytiscidae, Copelatinae): the non- erichsonii group species.

The genus Copelatus Erichson, 1832 (Coleoptera, Dytiscidae, Copelatinae) of Madagascar is revised in two parts. This review is restricted to the Copelatus species that have fewer than ten elytral + one submarginal stria, including all species except those of the erichsonii species group. Both morphological and molecular (mitochondrial COI) data are used in an integrative taxonomic approach. Thirteen species are recognised, of which five are described as new: Copelatus ankaratra sp. nov., Copelatus kely sp. nov., Copelatus pseudostriatus sp. nov., Copelatus safiotra sp. nov. and Copelatus vokoka sp. nov. Copelatus unguicularis Régimbart, 1903 and Copelatus apicalis Fairmaire, 1898 are both transferred to the genus Madaglymbus Shaverdo & Balke, 2008 (comb. nov.). Copelatus mimetesGuignot 1957 is a junior synonym of the widespread Afrotropical-Arabian Copelatus pulchellus (Klug, 1834) (syn. nov.). Copelatus marginipennis (Laporte, 1835) is reinstated (stat. nov.) as a valid species with Copelatus aldabricus Balfour-Browne, 1950 and Copelatus aldabricus var. simplex Guignot, 1952 as junior synonyms (syn. nov.). We designate lectotypes for Colymbetes marginipennis Laporte, 1835 and Copelatus obtusus Boheman, 1848. Copelatus peridinus Guignot, 1955 is recorded for Madagascar for the first time and Copelatus nodieri Régimbart, 1895 is rejected as a species present in Madagascar.

Discovery of a specialist Copelatinae fauna on Madagascar: highly ephemeral tropical forest floor depressions as an overlooked habitat for diving beetles (Coleoptera, Dytiscidae).

Diving beetles are generally aquatic and live submerged in water during larval and adult stages. A few groups have colonised hygropetric habitats and fewer species still can possibly be referred to as terrestrial. Here we describe six new Copelatine species that were mainly found in dry shallow forest floor depressions in the eastern and northeastern lowland humid forests of Madagascar. Three new species are described in each of the two genera Copelatus and Madaglymbus: Copelatus amphibius sp. nov., Copelatus betampona sp. nov., Copelatus zanatanensis sp. nov., Madaglymbus kelimaso sp. nov., Madaglymbus menalamba sp. nov., and Madaglymbus semifactus sp. nov. Diagnosis, description, known distribution, ecology, and conservation notes are provided for each species. All species are illustrated with a dorsal habitus image, ventral and lateral views of the male penis, and parameres. Photographs of the unusual terrestrial habitats where the species were found are provided. Madaglymbus menalamba sp. nov. is also documented with macrophotos and videorecordings of the terrestrial locomotion and behaviour in the field. Although these species should not be classified as terrestrial, or even semi-terrestrial Dytiscidae, they seem to be specialists of very ephemeral aquatic habitats and stay put instead of disperse when the habitat dries up. It is hypothesised that this lifestyle and behaviour on Madagascar is restricted to the high-precipitation humid forest regions mainly in the east. It may also represent a transition step, or stepping-stone, towards becoming fully terrestrial, a step that the few known terrestrial Dytiscid taxa once passed through. It is very likely that this type of habitat is overlooked for aquatic beetles, not only in Madagascar, and the six species herein described may be just the "tip of the iceberg".

Checklist of terrestrial Parasitengona mites in Fennoscandia with new species- and distribution records (Acariformes: Prostigmata).

The knowledge of terrestrial Parasitengona in Fennoscandia lies far behind that of their aquatic counterparts, the water mites (Hydrachnidia). Based on new inventories, we provide primary data and an annotated checklist of terrestrial Parasitengona in Fennoscandia including 107 species. Out of these, nineteen species are new findings for the region and five are species potentially new for science. Twenty-three species are new for Norway, fourteen for Finland and eleven for Sweden. The known recorded fauna today of terrestrial Parasitengona is 80 species for Norway, 54 for Sweden and 48 for Finland. Primary data include georeferenced locality data as well as collecting techniques and microhabitat to increase the knowledge on species' habitat requirements.

Sexual conflict and intrasexual polymorphism promote assortative mating and halt population differentiation.

Sexual conflict is thought to be an important evolutionary force in driving phenotypic diversification, population divergence, and speciation. However, empirical evidence is inconsistent with the generality that sexual conflict enhances population divergence. Here, we demonstrate an alternative evolutionary outcome in which sexual conflict plays a conservative role in maintaining male and female polymorphisms locally, rather than promoting population divergence. In diving beetles, female polymorphisms have evolved in response to male mating harassment and sexual conflict. We present the first empirical evidence that this female polymorphism is associated with (i) two distinct and sympatric male morphological mating clusters (morphs) and (ii) assortative mating between male and female morphs. Changes in mating traits in one sex led to a predictable change in the other sex which leads to predictable within-population evolutionary dynamics in male and female morph frequencies. Our results reveal that sexual conflict can lead to assortative mating between male offence and female defence traits, if a stable male and female mating polymorphisms are maintained. Stable male and female mating polymorphisms are an alternative outcome to an accelerating coevolutionary arms race driven by sexual conflict. Such stable polymorphisms challenge the common view of sexual conflict as an engine of rapid speciation via exaggerated coevolution between sexes.

Early burst in body size evolution is uncoupled from species diversification in diving beetles (Dytiscidae).

Changes in morphology are often thought to be linked to changes in species diversification, which is expected to leave a signal of early burst (EB) in phenotypic traits. However, such signal is rarely recovered in empirical phylogenies, even for groups with well-known adaptive radiation. Using a comprehensive phylogenetic approach in Dytiscidae, which harbours ~4,300 species with as much as 50-fold variation in body size among them, we ask whether pattern of species diversification correlates with morphological evolution. Additionally, we test whether the large variation in body size is linked to habitat preference and whether the latter influences species turnover. We found, in sharp contrast to most animal groups, that Dytiscidae body size evolution follows an early-burst model with subsequent high phylogenetic conservatism. However, we found no evidence for associated shifts in species diversification, which point to an uncoupled evolution of morphology and species diversification. We recovered the ancestral habitat of Dytiscidae as lentic (standing water), with many transitions to lotic habitat (running water) that are concomitant to a decrease in body size. Finally, we found no evidence for difference in net diversification rates between habitats nor difference in turnover in lentic and lotic species. This result, together with recent findings in dragonflies, contrasts with some theoretical expectations of the habitat stability hypothesis. Thus, a thorough reassessment of the impact of dispersal, gene flow and range size on the speciation process is needed to fully encompass the evolutionary consequences of the lentic-lotic divide for freshwater fauna.

To be or not to be a subspecies: description of Saperda populnea lapponica ssp. n. (Coleoptera, Cerambycidae) developing in downy willow (Salix lapponum L.).

A new subspecies of the European cerambycid Saperda populnea (Linnaeus, 1758) is described: Saperda populnea lapponicassp. n. based on specimens from Scandinavia. The male genitalia characters were examined and found to provide support for this separation, as well as differences in morphology, geographical distribution and bionomy. The preferred host tree for the nominate subspecies S. populnea populnea is Populus tremula L., whereas S. populnea lapponicassp. n. is considered to be monophagous on Salix lapponum L. DNA sequence data of mitochondrial cytochrome oxidase subunit I (COI) was generated from Scandinavian specimens of S. populnea populnea and specimens representing S. populnea lapponicassp. n. The two subspecies were not reciprocally monophyletic and genetic distances in COI were small. All synonyms of S. populnea populnea have been considered, and species similar to S. populnea populnea have been examined, and not found to be related to S. populnea lapponicassp. n. A male lectotype has been designated for each of the two following synonyms: Cerambyx decempunctatus De Geer, 1775, and Saperda salicis Zetterstedt, 1818. The synonymised species from Asia, S. balsamifera (Motshulsky, 1860), is elevated to subspecies: S. populnea balsamiferastat. n. We end with a discussion on the definition of subspecies under the unified species concept.