Jean-Yves Rasplus
email: jean-yves.rasplus@inra.fr

Bonnie B Blaimer

Seán G Brady

Roger A Burks

Gérard Delvare

Nicole Fisher

Michael Gates

Nathalie Gauthier

Alex V Gumovsky

Christer Hansson

John M Heraty

Lucian Fusu

Sabine Nidelet

Rodrigo A S Pereira

Laure Sauné

Rosichon Ubaidillah

Astrid Cruaud

A first phylogenomic hypothesis for Eulophidae (Hymenoptera, Chalcidoidea)

Keywords: Phylogenetics, ultraconserved element, UCEs, target enrichment, sequence

Eulophidae is a hyper-diverse family of chalcidoid wasps with 324 genera, about 5300 described species and probably thousands of others to be described. Until now, the absence of unequivocal morphological apomorphies and the low resolution provided by the handful of Sanger sequenced genes have hampered the reconstruction of phylogenetic relationships within the family. Here, we used ultra-conserved elements and their flanking regions to resolve relationships among 84 species of eulophids included in 63 genera representing all subfamilies and most tribes, plus 15 outgroups. Our analyses recover all traditional Eulophidae subfamilies and tribes with high support and globally agree with the traditional classification of the family. Our results confirm that Eulophinae + Tetrastichinae is the sister group of (Opheliminae + Entiinae) + Entedoninae. At the generic level, our analyses provide high support for intergeneric relationships for which morphology and Sanger markers previously failed to provide resolution. Our results also confirm that Trisecodes does not group with Eulophidae and may not belong to this family; however, its correct classification still awaits a large-scale phylogenomic hypothesis for Chalcidoidea. This work opens new avenues towards a better understanding of the evolutionary history, biogeography and evolution of host-parasitoid associations in this hyper-diverse family of chalcidoid wasps.

Introduction

With the exception of Pteromalidae, no other family of Chalcidoidea has evolved such a diversity of species and range of biological and ecological disparity as the Eulophidae. With 324 genera, about 5300 described species and probably thousands of others to be described [START_REF] Noyes | Universal Chalcidoidea Database[END_REF], eulophids represent one of the most diverse family of chalcidoid wasps. The family is represented in every region outside the Antarctic and in nearly all types of terrestrial habitats. In addition, eulophids exhibit a wide spectrum of life-history characteristics. They can be gall-makers [START_REF] Lasalle | Biology of gall inducers and evolution of gall induction in Chalcidoidea (Hymenoptera: Eulophidae, Eurytomidae, Pteromalidae, Tanaostigmatidae, Torymidae)[END_REF][START_REF] Kim | A new genus and species of Tetrastichinae (Hymenoptera: Eulophidae) inducing galls in seed capsules of Eucalyptus[END_REF][START_REF] Rasplus | A new afrotropical genus and species of Tetrastichinae (Hymenoptera: Eulophidae) inducing galls on Bikinia (Leguminosae: Caesalpinioideae) and a new species of Ormyrus (Hymenoptera: Ormyridae) associated with the gall[END_REF] or phytophagous on leaves, twigs or seeds although they are mostly parasitoids of larval and nymphal stages or adults of insects. Numerous species are primary parasitoids of leaf-feeding lepidopteran larvae as either idiobiont ectoparasitoids or koinobiont endoparasitoids, but many species are known to be ectoparasitic hyperparasitoids. According to current knowledge, species are often monophagous, but species groups or genera can be generalists or specialised on specific hosts (e.g. on Thysanoptera, Aleyrodidae). Multiple species belonging to different species groups are oophagous on Coleoptera, Hemiptera or Dictyoptera. Tetrastichinae develops at the expense of no less than 100 families of hosts belonging to 10 orders of insects [START_REF] Lasalle | North American genera of Tetrastichinae (Hymenoptera: Eulophidae)[END_REF]. Eulophidae mostly parasitise endophytic larvae of insects (Diptera, Coleoptera, Lepidoptera, Hymenoptera) but can also attack eggs of spiders, gall-forming mites or nematodes [START_REF] Berg | An unusual host association: Aprostocetus sp. (Eulophidae), a hymenopterous predator of the nematode Subanguina mobilis (Chit & Fisher, 1975) Brzeski[END_REF]. Therefore, eulophids are essential for regulating populations of phytophagous insects in natural ecosystems, and a number of eulophid species have been used in biological control programmes to regulate pests [START_REF] Hoy | Classical biological control of brown citrus aphid[END_REF][START_REF] Jaramillo | Biological control of the coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae) by Phymastichus coffea (Hymenoptera: Eulophidae) in Colombia[END_REF][START_REF] Duan | Establishment and abundance of Tetrastichus planipennisi (Hymenoptera: Eulophidae) in Michigan: potential for success in classical biocontrol of the invasive Emerald Ash Borer (Coleoptera: Buprestidae)[END_REF].

The monophyly of Eulophidae has never been challenged. However, only few synapomorphies support this traditional and morphological view [START_REF] Burks | Combined molecular and morphological phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with focus on the subfamily Entedoninae[END_REF]. Furthermore, most diagnostic characters that support the monophyly of the family are reductions such as the number of tarsomeres or antennomeres or are homoplastic across Chalcidoidea [e.g. that the mesotrochantinal plate is inflected and separated from the metasternum by a membrane, which also occurs in Agaonidae [START_REF] Heraty | A phylogenetic analysis of the megadiverse Chalcidoidea (Hymenoptera)[END_REF]]. Eulophidae is traditionally classified into five subfamilies (Entedoninae, Entiinae, Eulophinae, Opheliminae and Tetrastichinae) [START_REF] Bouček | Australasian Chalcidoidea (Hymenoptera): a biosystematic revision of genera of fourteen families, with a reclassification of species[END_REF]. Recently, [START_REF] Doğanlar | Systematics of the genera with reduced mandible of Eulophidae (Hymenoptera: Chalcidoidea): parasitoids of thrips (Thysanoptera)[END_REF] added a sixth subfamily (Ceranisinae) for a few genera with reduced mandibles that develop as larval parasitoids of Thysanoptera. However, this subfamily was subsequently synonymised with Entedoninae by [START_REF] Triapitsyn | New records of Eulophidae, Mymaridae, Pteromalidae and Tetracampidae (Hymenoptera: Chalcidoidea) from Russia, with annotations and description of a new species of Dicopus Enock[END_REF]. All subfamilies of Eulophidae are also rather poorly defined morphologically. Indeed, most morphological characters used to define suprageneric entities within Eulophidae appear to be highly homoplastic and variable at different taxonomic levels. Therefore, several subfamilies (e.g. Tetrastichinae, Entedoninae) and tribes (e.g. Entedonini) cannot be defined by a single or a set of morphological synapomorphies. Nevertheless, most molecular studies using Sanger sequencing have recovered Eulophidae as well as most subfamilies as monophyletic. However, inter-tribal and inter-generic relationships are still poorly resolved, often due to poor taxon sampling [START_REF] Campbell | Molecular systematic of the Chalcidoidea using 28S-rDNA[END_REF][START_REF] Gauthier | Phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with a reclassification of Eulophinae and the recognition that Elasmidae are derived eulophids[END_REF][START_REF] Munro | A molecular phylogeny of the Chalcidoidea (Hymenoptera)[END_REF][START_REF] Heraty | A phylogenetic analysis of the megadiverse Chalcidoidea (Hymenoptera)[END_REF].

Several studies have examined the generic relationships within Eulophidae [START_REF] Schauff | The holarctic genera of Entedoninae (Hymenoptera: Eulophidae)[END_REF][START_REF] Gauthier | Phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with a reclassification of Eulophinae and the recognition that Elasmidae are derived eulophids[END_REF][START_REF] Gumovsky | Monophyly and preliminary phylogeny of Entedoninae (Hymenoptera: Chalcidoidea: Eulophidae): 28s D2 rDNA considerations and morphological support[END_REF][START_REF] Gumovsky | Molecular data support the existence of four main lineages in the phylogeny of the family Eulophidae (Hymenoptera)[END_REF][START_REF] Sha | A molecular phylogeny of eulophid wasps inferred from partial 18S gene sequences[END_REF]. A recent study that combined molecules and morphology significantly enhanced our understanding of the evolutionary history of the family [START_REF] Burks | Combined molecular and morphological phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with focus on the subfamily Entedoninae[END_REF]. In this work (54 species included), as well as in Munro et al. (2011) (27 species included), the relationships between the subfamilies were well resolved, and the authors proposed that Eulophinae + Tetrastichinae was the sister group of (Opheliminae + Entiinae) + Entedoninae. Relationships within subfamilies were less well resolved. Until now, the absence of unequivocal morphological apomorphies and the low-resolution power of the sequenced genes have hampered the reconstruction of phylogenetic relationships within eulophid subfamilies. The challenge of elucidating evolutionary relationships among genera is further complicated by the homoplastic nature of multiple characters used to define the generic limits. Therefore, recent molecular advances combined with novel computational approaches represent an interesting opportunity to better understand the tree of life of Eulophidae. Indeed, it is now possible to sequence hundreds of markers at a reasonable cost to reduce stochastic errors and better resolve phylogenetic relationships.

Many methods are available to gather genome-scale data among which sequence capture is a scalable and affordable method for broad-scale phylogenetics [START_REF] Mamanova | Target-enrichment strategies for next-generation sequencing[END_REF][START_REF] Lemmon | High-throughput genomic data in systematics and phylogenetics[END_REF]). Among the main genomic regions that can be targeted, ultra-conserved elements (UCEs, [START_REF] Faircloth | Ultraconserved elements anchor thousands of genetic markers spanning multiple evolutionary timescales[END_REF][START_REF] Mccormack | Ultraconserved elements are novel phylogenomic markers that resolve placental mammal phylogeny when combined with species-tree analysis[END_REF] have been extensively used to reconstruct phylogeny in multiple groups of Hymenoptera, including Chalcidoidea [START_REF] Blaimer | Phylogenomic methods outperform traditional multi-locus approaches in resolving deep evolutionary history: a case study of formicine ants[END_REF](Blaimer et al. , 2016a;;[START_REF] Jesovnik | Phylogenomic species delimitation and host-symbiont coevolution in the fungus-farming ant genus Sericomyrmex Mayr (Hymenoptera: Formicidae): ultraconserved elements (UCEs) resolve a recent radiation[END_REF]Branstetter et al. 2017aBranstetter et al. , 2017b;;[START_REF] Bossert | On the universality of target-enrichment baits for phylogenomic research[END_REF][START_REF] Bossert | Combining transcriptomes and ultraconserved elements to illuminate the phylogeny of Apidae[END_REF][START_REF] Cruaud | Optimised DNA extraction and library preparation for minute arthropods: application to target enrichment in chalcid wasps used for biocontrol[END_REF][START_REF] Cruaud | Ultra-conserved elements and morphology reciprocally illuminate conflicting phylogenetic hypotheses in Chalcididae (Hymenoptera, Chalcidoidea)[END_REF]. UCEs are highly conserved regions of genomes shared among distant taxa, and specific set of probes have been designed to capture these regions in Hymenoptera [START_REF] Faircloth | Target enrichment of ultraconserved elements from arthropods provides a genomic perspective on relationships among Hymenoptera[END_REF]. The phylogenetic utility of UCEs and their more variable flanking regions has been demonstrated on multiple evolutionary scales, and they may also prove useful in contributing to decipher generic relationships within Eulophidae. Interestingly, the capture of UCEs does not necessarily require fresh specimens or high-quality DNA. Museum samples have been indeed successfully used [START_REF] Mccormack | Sequence capture of ultraconserved elements from bird museum specimens[END_REF]Blaimer et al. 2016b). Finally, fast and efficient protocols have been optimised to capture UCEs on individual tiny insects without destruction of the specimens, in a few days for a cost of about 50 USD per individual [START_REF] Cruaud | Optimised DNA extraction and library preparation for minute arthropods: application to target enrichment in chalcid wasps used for biocontrol[END_REF].

Until now, molecular studies of the family were based on data sets composed of a few tens of morphological characters, and sequences of about three to four genes obtained with traditional Sanger sequencing on less than 60 species. In this paper, and for the first time, we used hundreds of pangenomic markers (UCEs) and numerous taxa to investigate the Eulophidae tree of life with a data set representative of all subfamilies and most tribes. This work is a first step towards a better understanding of the evolutionary history of this hyper-diverse family.

Materials and methods

Sampling

Our sampling comprises 84 species included in 63 genera representing all subfamilies and most tribes plus 15 outgroups (Table S1). Samples were collected by authors of this paper or borrowed from the Queensland Museum (Australia) and the Australian National Insect Collection, Canberra. Three rare tribes of Eulophidae could not be included in our data set, namely Platytetracampini (Entedoninae),and Gyrolasomyiini (Tetrastichinae) each represented by one extant Australasian genus.

DNA extraction, library preparation and sequencing DNA was extracted non-destructively and vouchers were subsequently remounted on cards. DNA was extracted using the Qiagen DNeasy Blood and Tissue kit following the manufacturer's protocol with a few modifications detailed in [START_REF] Cruaud | Optimised DNA extraction and library preparation for minute arthropods: application to target enrichment in chalcid wasps used for biocontrol[END_REF]. Vouchers were deposited as detailed in Table S1. Library preparation followed [START_REF] Cruaud | Optimised DNA extraction and library preparation for minute arthropods: application to target enrichment in chalcid wasps used for biocontrol[END_REF]. Briefly, input DNA was sheared to a size of ca 400 bp using the Bioruptor® Pico (Diagenode). End repair, 3ʹ-end adenylation, adapter ligation and PCR enrichment were then performed with the NEBNext Ultra II DNA Library prep kit for Illumina (NEB). Adapters that contained amplification and Illumina sequencing primer sites, as well as a nucleotide barcode of 5 or 6 bp long for sample identification, were used to tag samples. Pools of 16 samples were made at equimolar ratio. Each pool was enriched using the 2749 probes (v1) designed by [START_REF] Faircloth | Target enrichment of ultraconserved elements from arthropods provides a genomic perspective on relationships among Hymenoptera[END_REF] using a MYbaits kit (Arbour Biosciences) and following the manufacturer's protocol. The hybridisation reaction was run for 24 h at 65°C. Postenrichment amplification was performed on beads with the KAPA Hifi HotStart ReadyMix. The enriched libraries were quantified with Qubit, an Agilent Bioanalizer and qPCR with the Library Quantification Kit -Illumina/Universal from KAPA (KK4824). They were then pooled at equimolar ratio. Paired-end sequencing (2*300 bp) was performed on an Illumina Miseq platform at UMR AGAP (Montpellier, France).

Data analysis

The analytical workflow followed [START_REF] Cruaud | Optimised DNA extraction and library preparation for minute arthropods: application to target enrichment in chalcid wasps used for biocontrol[END_REF]. Quality control checks were performed with FastQC v.0.11.2 [START_REF] Andrews | FastQCa quality control application for FastQ files[END_REF]. Quality filtering and adapter trimming were performed with Trimmomatic-0.36 [START_REF] Bolger | Trimmomatic: a flexible trimmer for Illumina sequence data[END_REF]. Overlapping reads were merged using FLASH-1.2.11 [START_REF] Magoc | FLASH: fast length adjustment of short reads to improve genome assemblies[END_REF] and demultiplexing was performed with a bash custom script (no mismatch in barcode sequences was allowed). Assembly of cleaned reads was performed using CAP3 [START_REF] Huang | CAP3: a DNA sequence assembly program[END_REF] and contigs were aligned to the set of reference UCEs using LASTZ Release 1.02.00 [START_REF] Harris | Improved pairwise alignment of genomic DNA[END_REF]. Contigs that aligned with more than one reference UCE and different contigs that aligned with the same reference UCE were filtered out using Geneious 8.1.8. (https://www. geneious.com).

UCEs for which sequences were available for more than 50% of the taxa were kept in the next steps of the analysis. Alignments were performed with MAFFT v7.245 [START_REF] Katoh | MAFFT multiple sequence alignment software version 7: improvements in performance and usability[END_REF]) (-linsi option). Ambiguously aligned blocks were removed using Gblocks_0.91b with relaxed constraints (-t = d -b2 = b1 -b3 = 10 -b4 = 2 -b5 = h) [START_REF] Talavera | Improvement of phylogenies after removing divergent and ambiguously aligned blocks from protein sequence alignments[END_REF]. The final data set was analysed using supermatrix approaches based on maximum likelihood (ML) as implemented in raxmlHPC-PTHREADS-AVX (Stamatakis 2014) (version 8.2.11) and IQ-TREE v1.6.7 [START_REF] Nguyen | IQ-TREE: A fast and effective stochastic algorithm for estimating maximum likelihood phylogenies[END_REF] and the coalescent-based summary method implemented in ASTRAL-III v5.6.3 [START_REF] Zhang | ASTRAL-III: polynomial time species tree reconstruction from partially resolved gene trees[END_REF]. For the RAxML analysis, a rapid bootstrap search (100 replicates) followed by a thorough ML search (-m GTRGAMMA) was performed. For the IQ-TREE analysis, 20 independent ML searches were conducted using the best-fit substitution model automatically selected by ModelFinder [START_REF] Kalyaanamoorthy | ModelFinder: fast model selection for accurate phylogenetic estimates[END_REF]) (candidate tree set for each search = 98 parsimony trees + BIONJ tree with only the 20 best initial trees retained for NNI search). Branch supports were assessed with ultrafast bootstrap [START_REF] Minh | Ultrafast approximation for phylogenetic bootstrap[END_REF]) and SH-aLRT test [START_REF] Guindon | New algorithms and methods to estimate maximum-likelihood phylogenies: assessing the performance of PhyML 3.0[END_REF]) (1000 replicates) as well as standard non-parametric bootstrap (100 replicates). A bootstrap convergence test was performed with RAxML using the extended majority-rule consensus tree criterion [START_REF] Pattengale | How many bootstrap replicates are necessary?[END_REF]. Individual trees were inferred from each UCE using RAxML (-f a -x 12,345 -p 12,345 -# 100 -m GTRGAMMA) and used as input for the ASTRAL analysis. To improve accuracy in the ASTRAL analyses, nodes within loci that had BP support <10 were collapsed in individual gene trees [START_REF] Zhang | ASTRAL-III: polynomial time species tree reconstruction from partially resolved gene trees[END_REF]) with the perl script AfterPhylo.pl [START_REF] Zhu | AfterPhylo. A Perl script for manipulating trees after phylogenetic reconstruction[END_REF]. Node supports were evaluated with local posterior probabilities (local PP). Summary statistics were calculated using AMAS [START_REF] Borowiec | AMAS: a fast tool for alignment manipulation and computing of summary statistics[END_REF]. Tree annotation was performed with TreeGraph 2.13 [START_REF] Stöver | TreeGraph 2: combining and visualizing evidence from different phylogenetic analyses[END_REF].

Computational resources

Analyses were performed on a Dell PowerEdge T630 server with two 10-core Intel(R) Xeon(R) CPUs E5-2687W v3 @ 3.10 GHz and on the Genotoul-bioinfo Cluster (INRA, Toulouse).

Results and discussion

UCE data set

The analysed data set included 99 taxa and 879 UCEs. Taxa were represented by 110-826 UCEs (median 688, Table S1; Figure 1). Ten taxa had more than 50% missing UCEs, and only two had more than 80% missing UCEs. The alignment cleaned with Gblocks contained 270,760 bp, 68.2% of which were parsimony informative. The percentage of missing data (due to capture failure in some taxa) was 24.7%, the percentage of gaps (that can either be created while aligning full-length UCEs or result from the capture of incomplete UCEs) was 8.6% and the GC content was 42.4%.

Phylogenetic inference

ModelFinder selected TIM+F + I+ G4 as the best-fit model for the concatenated data set (Bayesian Information Criterion). The 20 independent ML searches conducted with IQ-TREE converged to the same topology (Figure S1). The bootstrap convergence test indicated that stable support values were reached after 50 replicates of the standard nonparametric bootstrap. IQ-TREE and RAxML inferred identical and well-resolved topologies (Figures S1-S3). Fifteen nodes on 97 received standard bootstrap support values lower than 100 (Figure S1). Comparison of standard BP values (IQ-TREE), rapid BP values (RAxML) and ultrafast bootstrap values (UFBoot, IQ-TREE) did not indicate that either rapid BP or UFBoot largely overestimated node support (Figure S4). In two cases, rapid BP were 100 and UFBoot + SH-aLRT provided high support according to confidence thresholds mentioned in the IQ-TREE manual (i.e. SH-aLRT >80/UFBoot >95) when standard BP were only 88 and 78. In one case, UFBoot + SH-aLRT provided high support when standard BP and rapid BP were only 76 and 80, respectively. For all but three nodes, values of rapid BP were equal or lower than standard BP values. The ML and ASTRAL (Figure S5) trees were globally congruent. The consensus tree of these two approaches is presented in Figure 1. Only seven nodes that received poor statistical supports in both approaches (ML and ASTRAL) were in conflict (represented by polytomies in Figure 1). With the exception of the genus Trisecodes that clustered with the outgroups (sister to Tetracampidae), Eulophidae was recovered monophyletic (with high support only in the ML approach). All subfamilies and tribes were also recovered monophyletic with high support. The placement of the few specimens (n = 3) with a high proportion of missing data (<250 loci sequenced) agreed with morphology.

Our phylogenetic results support two major clades within Eulophidae: a clade formed by Tetrastichinae + Eulophinae and a clade containing Entedoninae sister to Entiinae + Opheliminae. This result corroborates the hypothesis of relationships among subfamilies proposed by [START_REF] Burks | Combined molecular and morphological phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with focus on the subfamily Entedoninae[END_REF] and [START_REF] Munro | A molecular phylogeny of the Chalcidoidea (Hymenoptera)[END_REF].

In contrast to previous phylogenetic studies that have reported high bootstrap support (>90%) for approximately half of the suprageneric nodes, our analyses recovered high support for about 90% of the suprageneric nodes (standard bootstrap ≥99). Our analyses provided strong support for a number of notable relationships within the subfamilies of Eulophidae. However, two clades had less supported relationships: (1) the Elachertus group of genera and (2) the Aprostocetus group of genera. Both clades show short internode branches that may be indicative of rapid diversification. Overall, these results highlight the power of UCEs to reconstruct a robust phylogenetic hypothesis for the family.

Trisecodes, the only eulophid with three segmented tarsi in female [START_REF] Delvare | Trisecodes gen.n. (Hymenoptera: Eulophidae: Entedoninae), the first Eulophid with three tarsal segments[END_REF], was previously classified as incertae sedis within Eulophidae [START_REF] Burks | Combined molecular and morphological phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with focus on the subfamily Entedoninae[END_REF]. Our analysis that includes the neotropical T. agromyzae Delvare and LaSalle, 2000, and the afrotropical T. africanum Gumovsky, 2014, supports other earlier studies that have placed Trisecodes as distantly related to other Eulophidae [START_REF] Burks | Combined molecular and morphological phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with focus on the subfamily Entedoninae[END_REF][START_REF] Munro | A molecular phylogeny of the Chalcidoidea (Hymenoptera)[END_REF][START_REF] Heraty | A phylogenetic analysis of the megadiverse Chalcidoidea (Hymenoptera)[END_REF]. Trisecodes is recovered as sister to Tetracampidae by both ML and ASTRAL approaches, but this relationship is only supported by ML approaches. Outgroup sampling being reduced, the most cautious conclusion at the time of this study is that Trisecodes does likely not belong to Eulophidae; however, its correct classification still awaits a large-scale phylogenomic hypothesis for Chalcidoidea.

Anselmella and Perthiola, two Australian genera belonging to the tribe Anselmellini [START_REF] Bouček | Australasian Chalcidoidea (Hymenoptera): a biosystematic revision of genera of fourteen families, with a reclassification of species[END_REF][START_REF] Reina | Revision of the genus Perthiola (Hymenoptera: Eulophidae: Anselmellini) with the description of a new species[END_REF], formed a strongly supported clade sister to the tribe Ophelimini. Consequently, the unplaced tribe Anselmellini belongs to the recently recognised subfamily Opheliminae [START_REF] Burks | Combined molecular and morphological phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with focus on the subfamily Entedoninae[END_REF], a result already suggested by [START_REF] Munro | A molecular phylogeny of the Chalcidoidea (Hymenoptera)[END_REF]. No tribal-level classification has yet been proposed for Entiinae, probably because the sampling of this subfamily has always been limited in previous phylogenetic studies.

Within Entedoninae, Euderomphalini (parasitoids of whiteflies) is recovered sister to Entedonini, a placement corroborated by the results from [START_REF] Burks | Combined molecular and morphological phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with focus on the subfamily Entedoninae[END_REF]. The only species of the genus Closterocerus subgenus Closterocerus included in this study was recovered sister to all other Entedonini, a result also similar to [START_REF] Burks | Combined molecular and morphological phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with focus on the subfamily Entedoninae[END_REF], yet with higher support. The second species of Closterocerus, belonging to the subgenus Achrysocharis, was nested within Entedonini and recovered sister to Horismenus with high statistical support in ML analyses. This result highlights the difficulty to reliably define some entedonine genera based only on morphology. Chrysonotomyia was recovered sister to all other Entedonini, and the remaining Entedonini was further subdivided into two groups of genera: (1) Entedon + Chrysocharis and Apleurotropis and (2) Pediobius + Kokandia + Mestocharis sister to Proacrias and Horismenus + Closterocerus (Achrysocharis). The first clade is well defined by one synapomorphy: the transverse carina on lateral pronotum (sometimes appearing as a semicircular plica) [START_REF] Gumovsky | Monophyly and preliminary phylogeny of Entedoninae (Hymenoptera: Chalcidoidea: Eulophidae): 28s D2 rDNA considerations and morphological support[END_REF][START_REF] Burks | Combined molecular and morphological phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with focus on the subfamily Entedoninae[END_REF].

Eulophinae is traditionally subdivided into two tribes -Cirrospilini and Eulophiniwhich is an arrangement confirmed by our results. Within Cirrospilini, the relationships observed between the genera globally match those observed by [START_REF] Ubaidillah | Cladistic analysis of morphological characters in the eulophine tribe Cirrospilini (Hymenoptera: Eulophidae)[END_REF] using 56 morphological characters. There are three clades within the tribe Eulophini: one corresponds to the Elachertus group of genera, another groups Sympiesis and Elasmus and the third includes all other genera of Eulophini included in our study. Our results confirmed the placement of Elasmus nested within Eulophinae. [START_REF] Gauthier | Phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with a reclassification of Eulophinae and the recognition that Elasmidae are derived eulophids[END_REF] synonymised the family Elasmidae with Eulophidae and Elasmus appeared sister to Sympiesis in our topologies. This relationship needs to be confirmed as it is not supported by morphology, which instead groups Sympiesis with Pnigalio and Hemiptarsenus. Hemiptarsenus is recovered paraphyletic with the two species included in our analysis forming a grade. This result confirms morphological analysis that also strongly suggested the para-or polyphyly of the genus [START_REF] Burks | Key to the Nearctic genera of Eulophidae, subfamilies: Entedoninae, Euderinae, and Eulophinae (Hymenoptera: Chalcidoidea)[END_REF], with some species found to render Sympiesis paraphyletic and some others most closely related to Pnigalio.

Tetrastichinae was subdivided into two strongly supported clades that match the hypothesis proposed by [START_REF] Graham | A reclassification of the European Tetrastichinae (Hymenoptera: Eulophidae), with a revision of certain genera[END_REF]: (1) the Aprostocetus group of genera and (2) the Tetrastichus group of genera. In the future, these entities may deserve a tribal status if analyses including a larger sampling of the genera of Tetrastichinae confirm this dichotomy. Within the Aprostocetus group of genera, our analyses recovered Minotetrastichus sister to all other genera. This result contradicts a previous hypothesis that suggested that Minotetrastichus was closely related to Aprostocetus [START_REF] Graham | A reclassification of the European Tetrastichinae (Hymenoptera: Eulophidae), with a revision of certain genera[END_REF]. This genus differs from other genera of the group by having extremely small propodeal spiracles. The Aprostocetus group of genera is further subdivided into three well-supported clades: (1) an Australian clade of gall-making tetrastichines sister to the New World genus Paragaleopsomyia; (2) a New World clade of genera containing Galeopsomyia and related genera and (3) a clade of genera closely related to Aprostocetus. These genera mostly occur in the Old World, but some are sub-cosmopolitan. Within this clade, Puklina + Crataepus render the genus Aprostocetus paraphyletic. This may raise questions about the validity of these genera as they may only represent derived species groups of Aprostocetus. However, this may also suggest that several species groups of Aprostocetus as presently defined deserve generic status.

Conclusion

We present the first phylogenomic hypothesis for Eulophidae using UCEs. At higher levels (tribes and subfamilies), our results were consistent with previous analyses based on morphology and a set of a few molecular markers. However, our analysis provides high support for most nodes, including intergeneric relationships for which morphology and previous molecular markers failed to provide robust resolution. Therefore, UCEs may represent ideal molecular markers for inferring a dense phylogeny of Eulophidae at a global level. The taxonomy of eulophids has been hampered by their homogenous morphology. In several groups of eulophids (Entedoninae, Tetrastichinae), the generic delimitation based on morphology has been challenging due to the difficulty to identify reliable characters. Among the several hundred genera of eulophids, only a few have been explicitly defined on the basis of synapomorphies. Given the lability of most morphological characters used to define genera, reconstructing a thorough phylogenetic hypothesis with dense sampling may help testing their monophyly and identifying useful characters for future generic classifications.

The current lack of a robust phylogenetic framework for Eulophidae is also a major drawback for many other areas of research, such as historical biogeography and the evolution of life-history traits. Indeed, eulophids exhibit a wide variety of biology (phytophagous, primary idiobiotic and koinobiotic parasitoids and hyperparasitoids) and a large spectrum of hosts, with multiple shifts between biologies and hosts. Few studies have examined the evolution of host ranges within Eulophidae. Identifying the most likely evolutionary pathways that led to the current disparity of Eulophidae lifestyles will, of course, depend on our ability to improve our knowledge of host-eulophid associations but also on our ability to produce a thoroughly documented and well-supported phylogeny of the family, which now appears feasible.

Figure 1 .

 1 Figure 1. Phylogenetic relationships among eulophids inferred from 879 UCEs. The IQTREE tree is used as template, and the number of UCEs analysed for each sample is given in brackets. Nodes that were not recovered by both approaches (supermatrices ML -RaxML/IQTREE and gene tree reconciliation ASTRAL) are collapsed. All nodes were highly supported (RAxML rapid BP >95; IQTREE SH-aLRT >80/UFBoot >95; IQTREE standard BP >95; ASTRAL local PP >0.8) unless specified with symbols. White squares indicate nodes that were observed in all trees but did not receive significant support (RAxML BP <95; IQTREE SH-aLRT <80/UFBoot <95; IQTREE standard BP <95; ASTRAL local PP <), grey squares indicate nodes supported only by ASTRAL (RAxML BP <95; IQTREE SH-aLRT <80/UFBoot <95; IQTREE standard BP <95; ASTRAL local PP >0.8), black squares indicate nodes supported only by ML approaches (RAxML BP >95; IQTREE SH-aLRT >80/UFBoot >95; IQTREE standard BP >95; ASTRAL local PP <0.8) and black triangles indicate nodes supported only by IQTREE with non-standard bootstrapping approaches (RAxML BP <95; IQTREE SH-aLRT >80/UFBoot >95; IQTREE standard BP <95; ASTRAL local PP <0.8). Complete RAxML, IQTREE and ASTRAL trees are available in Figures S1-S3, S5. Photos ©J.-Y. Rasplus. Scale bars = 500 µm.

J.-Y. RASPLUS ET AL.

Acknowledgements

We are grateful to Cedric Mariac and Leila Zekraoui (IRD, DIADE, France) for providing access to the Bioruptor; Audrey Weber (INRA, AGAP, France) for sequencing libraries; and the Genotoul bioinformatics platform Toulouse Occitanie, France, for providing computing resources. We thank the following persons for the loan or gift of material: Natalie Dale-Skey Papilloud and Andrew Polaszek (NHM, London); Thibaud Decaëns (CEFE, Montpellier); and Chris Burwell, Christine Lambkin and Susan Wright (Queensland Museum, Brisbane, Australia). Sampling in Brazil has been realised under the permanent permission for sampling zoological material (SISBIO 8775-1) delivered to Rodrigo A.S. Pereira. We thank the Queensland Government, Department of National Parks, Sport and Racing for delivering permits to sample in Queensland National Parks (Permits #WITK18248017-WITK18278817 to AC & JYR). This work is part of a large NSF project (NSF DEB 1555808) led by John Heraty, Jim Woolley and Matt Yoder that attempts to solve the phylogeny of the Chalcidoidea with NGS approaches and was funded by the INRA SPE department (recurrent funding to JYR and AC).

We dedicate this work to the memory of our dear friend and colleague John LaSalle, specialist of Eulophidae, who influenced all authors and published the first molecular phylogenetic hypothesis of the family with one of us (NG). John sent JYR many of the eulophid genera from Australia for sequencing and was an enthusiastic member of our project on the UCE phylogenomics of Chalcidoidea.

Data availability

Fastq raw reads are available as NCBI Sequence Read Archives (BioSamples IDs are listed in Table S1). The concatenated data set and newick tree files are available from Zenodo (https://doi.org/10. 5281/zenodo.3753257).

Disclosure statement

No potential conflict of interest was reported by the authors.