Research Hymenoptera Section

(Svenska Nematinae (Hymenoptera, Tenthredinidae) förutom Nematina-gruppen)

External funder: Svenska artprojektet – Swedish Taxonomy Initiative, STI
Funding: 3.000.000 SEK (ca. 350.000 €), funding period 2012-2015

Amongst the Tenthredinidae, the Nematinae show themselves to be as complicated as other insect groups which have been given the highest research priority within the well-funded Swedish Taxonomy Initiative (STI). Taxonomy and nomenclature of the group is in many ways chaotic. The fauna of Fennoscandia comprises more than 75% of the European Nematinae species. The project includes about 50 % of the Nematinae that are expected to occur in Sweden (i.e. all Nematinae with the exception of the subtribe Nematina). Of the approximately 300 European taxa that are to be considered, around 110 are already known from Sweden and 200 are already recorded from Fennoscandia.

Accordingly we expect not many less than 200 species in the group. An estimated 20 % of species or more probably require other names or may prove to be new to science. The few available comprehensive identification keys are from a modern viewpoint obsolete or lead to very inconclusive results. Only a handful of experts is currently capable of identifying a larger number of species, and often even these with much residual uncertainty.

A new classification and revision of this group is urgently required. In the course of the three year project, we intend to provide illustrated keys to the genera, species groups and species of Nematinae (excluding Nematina). To ensure a successful outcome, the work will involve numerous international collaborators.

External funder: BMBF 2003–2006; GBIF Seed Money Award 2005-2006; SYNTHESYS, several project applications 2008–2012)

ECatSym 3.10 (2011)

ECatSym 4.0 beta (2012)

ECatSym is the first online taxonomic catalogue that makes available comprehensive taxonomic data for the Symphyta. ECatSym covers about 6% of the megadiverse Hymenoptera. The catalogue meets the demands of the Global Biodiversity Information Facility (GBIF), in that taxonomic data are made freely available to everybody.

ECatSym offers the possibility of searching for the scientific and common names of species and genera, as well as their synonyms and misspelt names. The user is led to the valid name of the taxon that is sought and also can view associated images and literature references, together with information on distribution and higher classification. All data are based on the evaluation of about 9,000 publications (ca. 190,000 pages) on sawflies, mainly retro-digitalised and read with OCR, which can be made available, depending on copyright law, to other researchers. The high quality of information offered in ECatSym is reflected in the volume of data included. Currently, for example:

• 8.785 species and 831 genera,
• 30.855 name combinations,
• about 100.000 distributional data,
• about 200.000 links to literature.

ECatSym is continually updated as new publications appear. In the near future, data on host plants will be incorporated and made searchable. Furthermore, additional photos of type specimens will in future be included, as these become available as the result of work on various research collections. The static, printed version of the World Catalog of Symphyta (http://www.mapress.com/zootaxa/2010/1/zt02580p1064.pdf) appeared in 2010 in Zootaxa. A catalogue of family group names is currently being compiled.

The Megalodontesidae is a small exclusively Palearctic family of sawflies, considered to be the sister group of Pamphiliidae within Pamphilioidea if paleontological records are excluded.
About 40 valid species in one genus (Megalodontes) are currently known. Considering the low number of species, a (sub)generic division of the group seems not to be necessary. Existing generic names  are treated as synonyms (see Taeger 1998). About 5 species are still undescribed. A key to the European species is given by Taeger (2002).

Reliable information on the food plants is only available for 5 species: M. cephalotes (several Apiaceae: Peucedanum, Seseli, Libanotis, Laserpitium), M. nitens and M. skorniakowii on Ruta minor and Haplophyllum hirsutum, M. spiraeae on Sphallerocarpus gracilis, M. thor on Peucedanum spp. Other hostplant records are unreliable because of uncertain identifications of the wasps.

Barcoding (COI) seems to be a useful additional tool for species separation. Many taxa are very well supported by the barcoding results. Also morphologically very similar species (e.g., M. cephalotes & thor; M. eversmanni & reitteri) are clearly separated by their barcodes. On the other hand, morphologically clearly distinguishable species like M. quinquecinctus and spiraeae fall in the same barcode cluster. A revision of the world species is in preparation (Taeger, in prep.).

For as long as the systematics of the Hymenoptera have been discussed, attention has been focussed on the Ur-sawflies, or Xyelidae, because they are the most basal forms in this order and because of their great geological age (early Triassic –220 million years). Xyelidae form the sister group of the remaining Hymenoptera and accordingly must be considered first in any explanation of evolutionary trends within the Hymenoptera.

Although fossil forms were morphologically highly diverse, the recent species form five comparitively uniform groups: the Macroxyelinae Macroxyela (2 recent species on Ulmaceae) and Megaxyela (10 species on Juglandaceae), and the Xyelinae Pleroneura (12 species on Abies and Picea), Xyela (41 species on Pinus) and Xyelecia (2 species probably on Abies). Specifically, answers to the following questions are being sought:

• Taxonomy of Xyelidae species, concentrating on the Old World taxa;
• Ecological characteristics of Xyelidae species and their parasitoids;
• Conception of evolutionary scenarios that explain the radiation of species on the basis of phylogenetic hypotheses (morphological and genetic data).

The larvae of Xyela are predominantly monophagous and feed in the male flowers of pines. The narrow adaptation to this habitat was presumably the trigger for the enormous radiation of this group in the northern hemisphere. Probably only a fraction of these species, that are difficult to separate, has been described. Besides morphological data, barcoding often – but not consistently – is supportive for species differentiation.

The following publications are already available:

• Taxonomy and ecology of West Palaearctic Xyelidae;
• Vicariant species pairs of Xyela associated with Pinus densiflora in East Asia;
• Larval parasitoids of Xyela: Gelanes (Hymenoptera, Ichneumonidae);
• Taxonomy, host plants and distribution of the Eurasian species of Xyela.

Tenthredo in a broader sense is the largest sawfly genus, currently are treated more than 900 species (65 of these with subspecies) under this name. This is more than 10% of the known world fauna of sawflies. There are 33 genus group names within Tenthredo, partly used as subgeneric names, or even as valid genera. There is no general accepted system yet, a comprehensive phylogenetic analysis is still missing.

Tenthredo is restricted to the northern hemisphere, the southernmost record is from Sumatra. About 650 species are Palaearctic (Europe 100), 140 Nearctic, 300 Oriental. About 650 species are known from Asia, with highest diversity recorded from the Himalaya range. Especially the Asian taxa are poorly known, their variability is only known in few cases. In cooperation with foreign colleagues a re-classification of the group is intended for the future. Several papers were published during the last decades (Taeger 1985, 1988a, 1988b, 1991, 1992, 2013,  Blank & Taeger 2006) 

Supported by the SYNTHESYS program of the European Community during recent several important collections rich in type material were studied: Malaise collection (Stockholm), Mocsáry collection (Budapest, Taeger, 2013), Dusmet and Escalera collections (Madrid). Many types of Wei et al. (Changsha) were briefly checked and documented during an expedition to Yunnan and Sichuan in 2009. Comprehensive material from this area was collected there, to improve conditions at the SDEI for further studies in the group.

Although Orussidae are more than 1 cm long and often conspicuously coloured, they are comparitively rarely captured. The 85 known species form the sister group of the species-rich apocritan Hymenoptera, for which reason they occupy a key position in research on the phylogeny of the Apocrita and interpretation of the direction of character evolution. Orussidae are distributed worldwide. They are the only “Symphyta”, which live parasitically on other, xylobiont insects. The few available data implicate long-horn and jewel beetles (Cerambycidae, Buprestidae) as well as woodwasps (Siricidae, Xiphydriidae) as hosts.

The investigations involve descriptions of new species, the development of new identification keys, and the presentation of cladistic analyses of the species which are needed to help answer zoogeographical questions. For example, the distribution of the four Ophrynon species is restricted to California. They display a Californian-eremial type of distribution and are probably the product of a rather recent speciation event. Contrastingly, the analysis of 27 Orussus species indicates their Oriental origin (manuscript submitted). In the focus of a current investigation is a new Orussobaius species from the Island of Tanimbar (Lesser Sunda Islands), whose ancestor presumably originated in Australia. These studies are being conducted in close cooperation Lars Vilhelmsen (Copenhagen) and David R. Smith (Washington).

The following publications are already available or in preparation:

• Orussus smithi sp. n. and noted on other West Palaearctic Orussidae,
• Taxonomy, phylogeny and zoogeography of Ophrynon,
• Taxonomy, phylogeny and zoogeography of Orussus (in press, Insect Systematics & Evolution),
• Taxonomy and phylogeny of the ophrynopine clade of Orussidae (submitted).

More than 1.800 sawflies are currently known from the West Palaearctic. Their identification often causes problems, because existing keys were only devised for smaller geographical areas, are largely obsolete and insufficiently illustrated. A fundamental problem is caused by the mass of information contained in a practically unmanageable flood of very small publications. At the same time, the sawflies contain species whose correct identification is important, because they may occur as pests in agriculture, forestry and horticulture. Many species are also suitable for use as indicators in decision processes on nature conservation as one can find in Taeger et al. (1998) and are listed in Red Data Lists.

Because of these deficits the middle-term objective is to develop, in stages, the first identification work for the sawflies of the West Palaearctic. As well as the externally funded project “The Swedish Nematinae” (see above) the first steps have been made towards a revision of some other taxonomically critical groups, currently for example:

• Cephidae: Pachycephus, Trachelus
• Cimbicidae: Corynis (cooperation with Hans-Joachim Jacobs, Ranzin)
• Tenthredinidae: Tenthredopsis

Through the “Formosa Collection” of Hans Sauter (LINK: 1009683 ESAKI 1941.pdf) held at the SDEI, good contacts have for long existed with colleagues in the Peoples Republic of China and the Republic of China (Taiwan). In 2009 an Expedition to China Taeger & Blank 2010 was held and in 2011 an expedition to Taiwan (financed by DAAD and the National Science Council of Taiwan). Material collected during these expeditions is used in the faunal study of these countries and also in various systematic projects (e.g. Xyelidae, Tenthredo, see above).

Not quite 1400 species are at present counted in the fauna of European Sawflies (Taeger et al 2006). Distribution in the countries can be accessed in the Fauna Europaea. However, the level of current knowledge is deficitary in many countries, either because not enough material has been collected, or because the regions have been insufficiently treated in taxonomic works. The yearly International Sawfly Workshops organised by the SDEI are accordingly held preferably in such areas of Europe. The results are then published by an international team of colleagues, and serve as groundwork for the medium term project „Sawflies of the West Palaearctic)“ (see above):

●   Greece (in preparation)
●   Iran (cooperation with Mohammad Khayrandish, Tehran)
●   Portugal (in preparation)
●   Scotland (Liston et al 2012)
●   Slovakia (Roller et al 2006)

The checklist for Germany and the Red Data List issued by the Federal Agency for Nature Conservation have been thoroughly revised. Well-grounded data are now available for the sawflies, so that these can be used as indicators in evaluation of decisions that may affect nature conservation.