Oak Cynipid Research Articles

Network structure and taxonomic composition of tritrophic communities of Fagaceae, cynipid gallwasps and parasitoids in Sichuan, China

Abstract A key question in insect community ecology is whether parasitoid assemblages are structured by the food plants of their herbivore hosts. Tritrophic communities centred on oak‐feeding cynipid gallwasps are one of the best‐studied tritrophic insect communities. Previous work suggests that host plant identity is a much stronger predictor of oak–cynipid interactions than of cynipid–parasitoid interactions. However, these relationships have not been formally quantified. We reason that the potential for ‘bottom‐up’ effects should increase with host plant phylogenetic diversity. We, therefore, generated quantified interaction network data for previously unstudied tritrophic cynipid communities in Sichuan, China, where, in addition to Quercus, cynipid host plants include Castanea, Castanopsis and Lithocarpus. We characterise these communities taxonomically and compare the extent to which host plant taxonomy predicts plant–herbivore and plant–parasitoid associations. We sampled 42,620 cynipid galls of 176 morphotypes from 23 host plant species, yielding over 4500 specimens of 64 parasitoid morphospecies. Many parasitoids were identifiable to chalcidoid taxa present in other Holarctic oak cynipid communities, with the addition of Cynipencyrtus (Cynipencyrtidae). As elsewhere, Sichuan parasitoid assemblages were dominated by generalists. Gallwasp–plant interaction networks were significantly more modular than parasitoid–plant association networks. Gallwasps were significantly more specialised to host plants (i.e. had higher mean d' values) than parasitoids. Parasitoid assemblages nevertheless showed significant plant‐associated beta diversity, with a dominant turnover component. We summarise parallels between our study and other Fagaceae‐associated cynipid communities and discuss our findings in light of the processes thought to structure tritrophic interactions centred on endophytic insect herbivores.

Re-establishment of the Nearctic oak cynipid gall wasp genus Feron Kinsey, 1937 (Hymenoptera: Cynipidae: Cynipini), including the description of six new species.

The Nearctic cynipid oak gall wasp genus Feron Kinsey, comb. rev., is re-established with 34 species: F. albicomus (Weld, 1952), comb. nov., F. amphorus (Weld, 1926), comb. nov., F. apiarium (Weld, 1944), comb. nov., F. atrimentum (Kinsey, 1922), comb. nov., F. bakkeri (Lyon, 1984), comb. nov., F. caepula (Weld, 1926), comb. nov., F. californicum (Beutenmueller, 1911), comb. nov., F. clarkei (Bassett, 1890), comb. nov., F. comatum (Weld, 1952), comb. nov., F. crystallinum (Bassett, 1900), comb. nov., F. cylindratum (Kinsey, 1937), comb. nov., F. discale (Weld, 1926), comb. nov., F. discularis (Weld, 1926), comb. nov., F. dumosae (Weld, 1957), comb. nov., F. gigas (Kinsey, 1922), comb. nov., F. izabellae Melika, Nicholls & Stone, sp. nov., F. kingi (Bassett, 1900), comb. nov., F. parmula (Bassett, 1900), comb. nov., F. pattersonae (Fullaway, 1911), comb. nov., F. roberti Melika, Nicholls & Stone, sp. nov., F. rucklei Melika, Nicholls & Stone, sp. nov., F. scutellum (Weld, 1930), comb. nov., F. serranoae Pujade-Villar & Cuesta-Porta, sp. nov., F. splendens (Weld, 1919), comb. nov., F. stellare (Weld, 1926), comb. nov., F. stellulum (Burnett, 1974), comb. nov., F. sulfureum (Weld, 1926), comb. nov., F. syndicorum Pujade-Villar & Cuesta-Porta, sp. nov., F. tecturnarum (Kinsey, 1920), comb. nov., F. tetyanae Melika, sp. nov., F. tibiale Kinsey, 1937, comb. rev., F. tubifaciens (Weld, 1926), comb. nov., F. verutum Kinsey, 1937, comb. rev., and F. vitreum Kinsey, 1937, comb. rev. Most species are known only from the asexual generation; F. clarkei, F. comatum, and F. dumosae are known only from the sexual generation, while both generations are recognised for F. atrimentum, F. crystallinum, F. gigas, F. kingi, and F. pattersonae. Matching of alternate sexual and asexual generations is established for the first time for F. kingi and F. pattersonae (= Andricus pedicellatus (Kinsey, 1922), syn. nov.) based on molecular data (both cytb and ITS2 sequences). Morphological descriptions, re-descriptions, diagnoses, and a key to species are given, as well as data on DNA sequences, biology, phenology, and distribution.

A catalogue, revision, and regional perspective of Eastern Palaearctic and Oriental oak gall wasps and their inquilines (Hymenoptera: Cynipidae: Cynipini, Synergini, Ceroptresini).

Recent years have seen rapid advances in the study of Fagaceae-associated gall wasps (Hymenoptera: Cynipidae) of the Eastern Palaearctic and the Oriental (EPO) regions, for both the gall inducing Cynipini (commonly termed oak gall wasps though many species gall non-oak Fagaceae) and the predominantly inquiline tribes Synergini and Ceroptresini. This process has propagated some taxonomic errors and involves many taxa whose taxonomic status is uncertain. To provide a stable foundation for further advance, here we review the taxonomic status of the 212 species (133 oak gall wasps and 79 oak cynipid inquilines) that have been described or recorded in these regions. Of this total, we treat 171 as valid species names (103 oak gall wasps and 68 oak cynipid inquilines) in 20 genera; 22 as synonym names, 13 as incertae sedis, three as nomen dubium, and three as species inquirenda. Callirhytis kunugicola Shinji, 1944 is proposed as syn. nov. of C. kunugicola Shinji, 1943, as Shinji described the same species twice. For all valid species names, we provide taxonomic references, synonyms, and geographical distributions. We summarize what is known of host plant associations and gall locations for gall inducers, and host associations for inquilines. We discuss geographic patterns in the known richness of currently valid species for both groups of organisms, and place this in the context of the biogeography of available Fagaceae host plants. We provide a brief historical review of the study of oak gall wasps and their inquilines in the EPO regions.

Pairing of sexual and asexual generations of Nearctic oak gallwasps, with new synonyms and new species names (Hymenoptera: Cynipidae, Cynipini).

Most oak gallwasps (Hymenoptera; Cynipidae, Cynipini) have lifecycles involving obligate alternation between a sexual and an asexual generation. Many species are currently known from only one of these generations, with the alternate generation either unknown or separately described with a different name. Here we describe previously unknown generations for 12 Nearctic oak cynipids. We describe the sexual generation for ten species previously known only from an asexual generation: Acraspis quercushirta (Bassett, 1864), Acraspis villosa Gillette, 1888, Amphibolips spinosa Ashmead, 1887, Andricus balanaspis (Weld, 1922), comb. nov., Antron quercusnubila (Bassett, 1881), Bassettia pallida Ashmead, 1896, Neuroterus floccosus (Bassett, 1881), comb. rev., Philonix fulvicollis Fitch, 1859, Phylloteras poculum (Osten Sacken, 1862) and Sphaeroteras carolina (Ashmead, 1887), comb. rev.. We describe the asexual generation of Bassettia flavipes (Gillette, 1889), comb. nov. and Melikaiella tumifica (Osten Sacken, 1865), both previously known only from a sexual generation. Three described taxa (Neuroterus vernus Gillette, 1889, syn. nov., Neuroterus papillosus Beutenmueller, 1910, syn. nov. and Neuroterus perminimus Bassett, 1900, syn. nov.) are all identified as the sexual generation of Neuroterus niger Gillette, 1888. We also comment on the presence of previously unknown non-functional males reared from galls of the asexual generation of Neuroterus niger. We identify two further synonyms: Acraspis macrocarpae Bassett, 1890 is syn. nov. of A. quercushirta (Bassett, 1864), and Bassettia archboldi Melika Abrahamson, 2007 is syn. nov. of Bassettia pallida Ashmead, 1896. In addition, we formally synonymise multiple varieties described by Kinsey within his Acraspis quercushirta, A. villosa, Antron quercusnubila, Neuroterus niger and Philonix fulvicollis species complexes. We provide descriptions and diagnoses for these taxa, and summarise what is known of their biology, including host associations. All taxa and relationships between alternate generations are supported by morphological and molecular data.

Re-establishment of the Nearctic oak cynipid gall wasp genus Druon Kinsey, 1937 (Hymenoptera: Cynipidae: Cynipini), with description of five new species.

The Nearctic cynipid oak gall wasp genus Druon Kinsey comb. rev. is re-established, with 5 new species and 10 species previously placed in the genus Andricus Hartig 1840: D. alexandri Melika, Nicholls Stone, sp. nov., D. flocculentum (Lyon), comb. nov., D. fullawayi (Beutenmller), comb. nov., D. garciamartinonae Pujade-Villar, sp. nov., D. gregori Melika, Nicholls Stone, sp. nov., D. hansoni Cuesta-Porta, Melika Pujade-Villar, sp. nov., D. ignotum (Bassett), comb. nov., D. linaria Kinsey, comb. rev., D. pattoni (Bassett), comb. nov., D. protagion Kinsey, comb. rev. (D. malinum Kinsey, syn. nov., D. polymorphae Kinsey, syn. nov.), D. quercusflocci (Walsh), comb. nov., D. quercuslanigerum (Ashmead), comb. nov., D. receptum Kinsey, comb. rev., D. rusticum Kinsey, comb. rev. and D. serretae Pujade-Villar, Cuesta-Porta Melika, sp. nov.. All species are known only from their asexual generation except for D. ignotum and D. quercuslanigerum, for which alternating asexual and sexual generations are known. The sexual generation of D. ignotum and a new morphological variety of D. quercuslanigerum from Mexico are both described for the first time. We provide descriptions, redescriptions, diagnoses, keys to species, DNA sequence data and analyses, and information on biology, phenology, and distribution. Additionally, four Andricus species with woolly galls and striato-reticulated metasomas are transferred to Striatoandricus Pujade-Villar: S. furnessulus, comb. nov., S. furnessae, comb. nov., S. guatemalensis, comb. nov., and S. tenuicornis, comb. nov.

Discordant Pleistocene population size histories in a guild of hymenopteran parasitoids.

Signatures of past changes in population size have been detected in genome-wide variation in many species. However, the causes of such demographic changes and the extent to which they are shared across co-distributed species remain poorly understood. During Pleistocene glacial maxima, many temperate European species were confined to southern refugia. While vicariance and range expansion processes associated with glacial cycles have been widely documented, it is unclear whether refugial populations of co-distributed species have experienced shared histories of population size change. We analyse whole-genome sequence data to reconstruct and compare demographic histories during the Quaternary for Iberian refuge populations in a single ecological guild (seven species of chalcid parasitoid wasps associated with oak cynipid galls). For four of these species, we find support for large changes in effective population size (Ne ) through the Pleistocene that coincide with major climate events. However, there is little evidence that the timing, direction and magnitude of demographic change are shared across species, suggesting that demographic histories in this guild are largely idiosyncratic, even at the scale of a single glacial refugium.

Disentangling the effects of the invasive pest, Dryocosmus kuriphilus, and the introduction of the biocontrol agent, Torymus sinensis, on native parasitoids in an isolated insular chestnut-growing area

Dryocosmus kuriphilus Yasumatsu (Hymenoptera Cynipidae) was first recorded in Sardinia (Italy) in 2007. Two years later a biological control program started with the introduction of its non-native parasitoid, Torymus sinensis Kamijo (Hymenoptera Torymidae). Over a nine-year period (2009–2017), data on the relative abundance of D. kuriphilus, its native parasitoids and T. sinensis were collected. Native parasitoids reacted quickly to the large availability of hosts. However, a dramatic change in the abundance of each native species was recorded from year to year. In the first few years, the native parasitoid community and pest abundance did not fluctuate much. The turning point was 2014, when, at the same time, the native parasitoid populations increased and the T. sinensis populations also began to increase. In the following year, both the D. kuriphilus and native parasitoid populations decreased considerably, whereas the T. sinensis populations reached over 50% parasitism. The univoltine D. kuriphilus acted as an asynchronous resource for native bivoltine parasitoids. An asynchronous host-parasitoid interaction produces wide fluctuations in their populations. In this case, D. kuriphilus strongly altered the local community, which was subjected to a chaotic change in composition and species abundance. When T. sinensis became established, it monopolized the pest, making this resource unavailable to native parasitoids that returned to attack almost exclusively the native oak cynipids. In fact, the successful control of D. kuriphilus by the introduction of T. sinensis rebalanced the situation that had been altered by the arrival of the invasive pest.

A Taxonomic Review of the Gall Wasp Genus Saphonecrus Dalla-Torre and Kieffer and other Oak Cynipid Inquilines (Hymenoptera: Cynipidae) from Mainland China, with Updated Keys to Eastern Palaearctic and Oriental Species.

After the examination of the oak cynipid inquilines deposited in the Parasitic Hymenoptera Collection of the Agriculture and Forestry University of Zhejiang (ZAFU, China), we provide a revision of the species of Saphonecrus, Lithosaphonecrus, Ufo (Hymenoptera: Cynipidae: Synergini) and Ceroptres (Hymenoptera: Cynipidae: Ceroptresini) found in mainland China. Two new species of Saphonecrus are described: S. albidus Lobato-Vila and Pujade-Villar, sp. nov. and S. segmentatus Lobato-Vila and Pujade-Villar, sp. nov. Four Saphonecrus species (S. gilvus Melika and Schwéger, 2015, S. globosus Schwéger and Tang, 2015, S. leleyi Melika and Schwéger, 2015, and S. nantoui Tang, Schwéger and Melika, 2015) are new records for this region. We also provide new data on the biology and distribution, redescriptions, illustrations and corrections to some of the species, as well as updated keys to Eastern Palaearctic and Oriental species of Saphonecrus and Ufo. Three species of Saphonecrus are considered to have an uncertain status: S. gemmariae (Ashmead, 1885) incertae sedis from the USA, S. excisus (Kieffer, 1904) nomen dubium from India, and S. sinicus Belizin, 1968 incertae sedis from China. The validity of Saphonecrus in the Nearctic region as well as the current status of S. serratus Weld, 1926 from the Philippines and S. favanus Weld, 1944 from the USA are discussed.

Gall Forming Wasp Species of Oak Forests in Bolu

Oak cynipid galls were collected between 2006-2019 to reveal species diversity of oak gall wasps (Hymenoptera, Cynipidae, Cynipini) in Bolu. Collected galls were brought to laboratory and kept at room temperature in jars covered by tulle until adult cynipid wasps emerged. As a result, 44 species from 8 genera showed that Andricus is the most specious genus with 26 species. Our results indicate that Bolu bears high gall wasp species diversity. In this study, new distribution ranges are provided for most of the cynipid species previously reported for Turkey.

Fauna osa šišaruša hrasta kitnjaka na Fruškoj gori

This study presents investigation of sessile oak cynipid gall wasps fauna of Mt Fruška Gora. Gall wasps are insects, from the family Cynipidae, that induces galls mainly on oaks. Complex of sessile oak cynipid gall wasps were investigated during 4-year period (2016 - 2019). The survey was carried out on five sites: Kraljeve stolice, Spomenik, Brankovac, Ležimir and Rohalj baze. At total, number of seventeen cynipid gall wasps species were identified: Andricus aries (Girauld, 1859), Andricus caliciformis (Giraud, 1859), Andricus coriarius (Hartig, 1843), Andricus curvator (Hartig, 1840), Andricus dentimitratus (Rejto, 1887), Andricus glutinosus (Giraud, 1859), Andricus kollari (Hartig, 1843), Andricus lignicolus (Hartig,1840), Andricus lucidus (Hartig, 1843), Andricus solitarius (Fonscolombe, 1832), Cynips quercusfolii (Linnaeus, 1758), Cynips quercus (Fourcroy, 1785), Biorhiza pallida (Oliver, 1791), Neuroterus albipes (Schenck, 1863), Neuroterus anthracinus (Curtis, 1838), Neuroterus numismalis (Fourcroy, 1785) and Neuroterus quercusbaccarum (Linnaeus, 1758). Gall wasp A. dentimitratus is first record for Serbia. The most frequent species were A. lignicolus and A. glutinosus, which were found on all five observed sites.

The invasive ACGW Dryocosmus kuriphilus (Hymenoptera: Cynipidae) in Spain: native parasitoid recruitment and association with oak gall inducers in Catalonia

AbstractThe Asian chestnut gall wasp (ACGW), Dryocosmus kuriphilus (Hymenoptera: Cynipidae), is an invasive pest that affects chestnut trees. The first record of this pest in Spain was in 2012, in Catalonia, and it is now distributed in virtually every chestnut growing area in the country. In this study, we present an overview of parasitoid recruitment by ACGW in Catalonia over a 4-year period (2013–2016) comparing parasitoid communities attacking galls on oak and chestnut trees at the same sites. A total of 22 species of native parasitoids that normally attack oak cynipids emerged from ACGW galls, together with the non-native Torymus sinensis. The most abundant species were Bootanomyia dorsalis, Torymus flavipes, Ormyrus pomaceus and Eupelmus urozonus. The study also found that 20 of the 22 native parasitoids in ACGW galls were also reared from galls of 13 species of oak gall inducer (12 Cynipidae, 1 Cecidomyiidae).

The oak gall wasps of Israel (Hymenoptera, Cynipidae, Cynipini)-diversity, distribution and life history.

Oak-galling wasps (Hymenoptera: Cynipidae, Cynipini) have been studied in Israel only superficially so far, despite interest in the Israeli fauna given its location at the southern edge of distribution range of the wasps and their oak hosts. We provide the first comprehensive review of the Israeli fauna of oak cynipids based on an extensive survey of the five naturally occurring oak species in Israel. We report 53 cynipid species, 37 of which are reported from Israel for the first time, 10 are currently known only from this country, and 9 are undescribed. With 27 species, Andricus is by far the biggest genus in Israel, followed by Cerroneuroterus, Neuroterus Plagiotrochus, and Pseudoneuroterus with 4 species each. Andricus megalucidus is synonymized under A. cecconii and Cerroneuroterus cerrifloralis is synonymized under C. lanuginosus. The sexual generations of Andricus cecconii, A. coriariformis, A. coriarius, A. miriami, Cerroneuroterus lanuginosus and Pseudoneuroterus macropterus are reported here for the first time. We recorded 65 gall types, with bud galls being the most common and conspicuous, followed by leaf and catkin galls. We provide illustrated keys for all Israeli species based on their galls, as well as information on host associations, life history, phenology and distribution patterns where available. 21 cynipid species are associated with Quercus ithaburensis and 27 species are associated with Q. boissieri, whereas Q. libani, Q. calliprinos and Q. cerris host much fewer species. Most species are currently known from either their sexual or asexual generation while only 24% of them are known from both. Mount Hermon was found to be an important hotspot, hosting about half of the Israeli cynipid fauna, and species richness generally declines from the Golan Heights southwards to the Judean Mountains. Cynipid species that are associated with oaks of sections Cerris and Quercus in Europe are mostly associated with the same sections in Israel.

Description of Five New Species of Inquiline Oak Gall Wasps of the Genus Synergus Hartig (Hymenoptera, Cynipidae: Synergini) with Partially Smooth Mesopleurae From Mexico.

Irene Lobato-Vila and Juli Pujade-Villar (2017) Here we describe ve new species of Synergus Hartig with partially smooth mesopleurae that were obtained from oak cynipid galls on different species of Quercus L. in Mexico: Synergus cibriani sp. nov., Synergus gilletti sp. nov., Synergus longimalaris sp. nov., Synergus longiscapus sp. nov. and Synergus striatifrons sp. nov. To date, this trait has been observed in at least 18 American species, 16 recorded in North America (United States of America) and only 2 in Central America (Panama): Synergus elegans Nieves-Aldrey and Medianero and Synergus laticephalus Nieves-Aldrey and Medianero. The type material and additional material of Synergus punctatus Gillette from the United States have been examined and compared with S. gilletti sp. nov. The type material and additional material of S. elegans from Panama and Synergus citriformis (Ashmead) from the United States have also been examined and compared. This study records Synergus elegans in Mexico for the first time and classifies it as a syn. nov. of S. citriformis. Descriptions and diagnoses for the new species and a key to their identification and differentiation from their closest related species are given. Their distribution and host associations are also commented on.

Invasive chestnut gall wasp Dryocosmus kuriphilus (Hymenoptera: Cynipidae), its native parasitoid community and association with oak gall wasps in Slovenia

The Asian chestnut gall wasp (ACGW), Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae), is a global pest of chestnut trees. This pest was first recorded in Slovenia in 2005. Despite strict phytosanitary measures it was present throughout the country in native chestnut stands by 2013. We provide here the first overview of the parasitoids of ACGW in Slovenia recorded over a 4-year period and the direct interactions between parasitoid communities attacking hosts on chestnut and oaks at the same sites. A total of 27 species of native parasitoids that normally parasitize oak cynipids emerged from ACGW galls. The most abundant species were Torymus flavipes and Eupelmus urozonus. Seven species appear to be geographically well distributed in Slovenia. Twelve species of oak gall wasp were parasitized by 19 species of parasitoids. All native parasitoids have broad host ranges, so a large parasitoid diversity within this community can be expected. This is a novel study comparing the parasitoid communities associated with chestnut and oak galls.

Twelve oak gall wasp species (Hymenoptera, Cynipidae) new to the Turkish fauna

This study was conducted to contribute to the Turkish oak gall wasp fauna (Hymenoptera: Cynipidae). Oak cynipid galls were collected between 2011 and 2013 from different regions of Turkey; we found that Andricus assarehi, A. Coriariformis, A. Csokai, A. Glandulae, Andricus legitimus, A. Paradoxus, A. Sadeghii, A. Serotinus, A. Stellatus, A. Trotteri, Cynips longiventris, and Trigonaspis megaptera were new to the Turkish Cynipidae fauna. A new distribution range is also provided for the previously recorded gall wasp species Andricus pseudoaries.

DRYOCOSMUS KURIPHILUS YASUMATSU: AN OUTLINE SEVEN YEARS AFTER THE FIRST REPORT IN PIEDMONT (ITALY)

In 2002, for the first time in Europe, the oriental chestnut gall wasp (CGW), D. kuriphilus, was reported spreading in a large chestnut area in the south of Piedmont (Northwest Italy). Movement of infested plants from nurseries of this area has allowed the pest to progressively reach many other regions in Italy. CGW infestation has contributed, together with other factors such as drought and fungal diseases, to a significant reduction in chestnut fruits production. Death of chestnut trees due to CGW attack, however, has so far never been observed. Chemical treatments have proved ineffective for preventing the diffusion of this pest. Indigenous parasitoids, shifting from oak cynipids, show a low rate of parasitization on CGW. Since the first years of the outbreak, the Plant Health Service of Regione Piemonte has been trying to face the emergency, developing different activities: monitoring of chestnut areas, survey of nurseries, funding of research projects for biological control and evaluation of cultivar susceptibility.

Concordant phylogeography and cryptic speciation in two Western Palaearctic oak gall parasitoid species complexes

Little is known about the evolutionary history of most complex multi-trophic insect communities. Widespread species from different trophic levels might evolve in parallel, showing similar spatial patterns and either congruent temporal patterns (Contemporary Host-tracking) or later divergence in higher trophic levels (Delayed Host-tracking). Alternatively, host shifts by natural enemies among communities centred on different host resources could disrupt any common community phylogeographic pattern. We examined these alternative models using two Megastigmus parasitoid morphospecies associated with oak cynipid galls sampled throughout their Western Palaearctic distributions. Based on existing host cynipid data, a parallel evolution model predicts that eastern regions of the Western Palaearctic should contain ancestral populations with range expansions across Europe about 1.6 million years ago and deeper species-level divergence at both 8-9 and 4-5 million years ago. Sequence data from mitochondrial cytochrome b and multiple nuclear genes showed similar phylogenetic patterns and revealed cryptic genetic species within both morphospecies, indicating greater diversity in these communities than previously thought. Phylogeographic divergence was apparent in most cryptic species between relatively stable, diverse, putatively ancestral populations in Asia Minor and the Middle East, and genetically depauperate, rapidly expanding populations in Europe, paralleling patterns in host gallwasp species. Mitochondrial and nuclear data also suggested that Europe may have been colonized multiple times from eastern source populations since the late Miocene. Temporal patterns of lineage divergence were congruent within and across trophic levels, supporting the Contemporary Host-tracking Hypothesis for community evolution.

Phylogeny and DNA barcoding of inquiline oak gallwasps (Hymenoptera: Cynipidae) of the Western Palaearctic

We examine phylogenetic relationships within the Synergus complex of herbivorous inquiline gallwasps (Hymenoptera; Cynipidae; Synergini) associated with cynipid host galls on oak, a biologically diverse group whose genus-level morphological taxonomy has long been considered stable but whose species level taxonomy is problematic. We incorporate data for over 70% of recognised Western Palaearctic species in five morphology-based genera (Ceroptres, Saphonecrus, Synergus, Synophrus, Ufo), comprising sequence for two mitochondrial loci (coxI, cytb) and one nuclear locus (28S D2). In particular, we assess the evidence for monophyly of two long-established, morphology-defined sections within the genus Synergus that differ in a range of biological traits. To aid analyses of ecological interactions within oak cynipid communities, we also consider the utility of cytochrome oxidase I (coxI) DNA barcodes in the oak inquilines. In this assessment, we do not assume that species are delineated at a single threshold value of sequence divergence for a single gene, but examine concordance in the composition of molecular operational Taxonomic units (MOTUs) across a range of sequence divergences in each gene and across genes. We also assess the impact of sampling effort on MOTU stability.Phylogenetic reconstructions for all three loci support monophyly for Synergus and Synophrus, but reject monophyly for Saphonecrus and for the two sections within Synergus. The suites of traits associated with the two sections of the genus Synergus are thus homoplasious. All three loci also reject monophyly for three Synergus species (S. hayneanus, S. pallipes, S. umbraculus). Sequences for each locus identify robust MOTUs that are largely concordant across loci for a range of cut-off values. Though many MOTU’s correspond to recognised Linnean species, there is significant, multigene disagreement between groupings supported by morphology and sequence data, with both allocation of different morphospecies to the same MOTU and allocation of the same morphospecies to multiple MOTUs, regardless of cut-off value. Our results imply that while DNA barcoding has considerable utility within this group, morphology-based identification needs major revision at both genus and species levels. Further, lifehistory traits currently attributed to single morphospecies probably confound attributes of multiple lineages. Revealing patterns of character state evolution in Synergus requires collection of new host association and life history data explicitly linked to DNA barcode data for the specimens concerned.

Native and introduced parasitoids attacking the invasive chestnut gall wasp Dryocosmus kuriphilus

The globally invasive chestnut gall wasp Dryocosmus kuriphilus was recently reported in Italy and threatens European chestnut orchards and native forests. Of Chinese origin, this species has invaded Japan, Korea, the USA, Nepal and Europe and in each region it has been attacked by parasitoids exploiting oak gall wasps. Classical biological control using the parasitoid Torymus sinensis (Hymenoptera: Torymidae) successfully reduced infestation in Japan. Subsequent work in Japan and Korea showed this parasitoid to represent a poorly understood and biologically diverse species complex. Following its success in Japan, T. sinensis was released in Italy in 2005. A growing appreciation of the taxonomic and ecological complexity of the T. sinensis complex in Japan and Korea has stimulated ongoing DNA‐based work on relationships and interbreeding of species in this group. Oak cynipid parasitoids provide potential for native augmentative or conservation biological control of D. kuriphilus in Europe. Exploitation of this potential requires improved understanding of the taxonomy of these parasitoids, particularly of morphologically highly conserved lineages such as Eurytoma and Eupelmus in which recognised species may contain many cryptic lineages. There is a growing need for a molecular survey of the communities centered on chestnut and oak gall wasps to: (1) ascertain the identity of T. sinensis lineages released in Italy (2) track the dispersal of T. sinensis in the native community, either in its original form or as hybrids with native species (3) identify possible biological control agents in the native parasitoid community.

The phylogenetic relationships betweenDryocosmus,Chilaspisand allied genera of oak gallwasps (Hymenoptera, Cynipidae: Cynipini)

AbstractOak gallwasps (Hymenoptera; Cynipidae, tribe Cynipini) are cyclically parthenogenetic insects that induce galls on specific plant hosts in the family Fagaceae. Understanding the processes underlying the evolution of specific oak associations requires knowledge of the phylogenetic relationships among oak gallwasp genera. Although three major lineages of oak gallwasps have been identified, the status and relationships of several species‐poor but biologically significant genera remain unresolved. Two such genera areChilaspisandDryocosmus, whose western palaearctic species all gall oaks in the sectionCerris.Dryocosmusis particularly significant biologically because it includes: (a) the only palaearctic gallwasp to gall chestnuts,Castanea, and (b) nearctic species. The oak sectionCerrisis wholly absent from the nearctic, and the relationship between palaearctic and nearcticDryocosmusis significant for patterns of host plant evolution in the tribe as a whole. We examined the relationships betweenChilaspis,Dryocosmusand other oak cynipid genera using cladograms from sequence data for two mitochondrial loci (cytochromecoxidase subunit I and cytochromeb) and two nuclear loci (the 28S ribosomal gene regions D2 and D3–5). Our analyses support the following conclusions: (1) palaearcticChilaspisandDryocosmusspecies form an intermingled monophyletic group. (2) We propose thatChilaspisMayr, 1881 is asyn.n.ofDryocosmusGiraud, 1859 and propose the nameD. mayrias acomb.rev.for the species previously namedC. mayri, andD. nitidusandD. israeliascomb.n.ofC. nitidaandC. israeli, respectively. (3) We reassess the utility of morphological characters previously regarded as diagnostic for these genera. (4) Two species previously known only from a single generation represent two halves of a single species lifecycle.Dryocosmus nervosusis here designated asyn.n.ofD. cerriphilus. (5) The nearctic speciesD. favuslies outside the palaearcticChilaspis/Dryocosmusclade, andDryocosmusas currently recognized is not a monophyletic group. (6)Dryocosmus/Chilaspisis closely related to the other oak gallwasp taxa (Aphelonyx,Plagiotrochus,Pseudoneuroterus,Trichagalma, and someNeuroterusspecies) galling sectionCerrisoaks. This implies an early branching evolution of this oak association within this group, and supports previous work showing the rarity of oak gallwasp host shifts.