Chorebus cylindricus (Telenga, 1935)

Godfray, Charles J. & Achterberg, Cornelis Van, 2024, Annotated Checklist of the European Dacnusini and the Dapsilarthra genus group of the Alysiini (Hymenoptera: Braconidae, Alysiinae), Zootaxa 5513 (1), pp. 1-73 : 5-7

cylindricus (Telenga, 1934; Dacnusa ) [1]

Synonymy: cybele ( Nixon, 1937, Dacnusa ); synonymy by Tobias (1986). [2]

Group: 4c. [3]

Literature: Nixon 1944 -143 (K 1943-165); Griffiths IV-683 [VII-353] (K IV-682); Tobias (270). [4]

Hosts: Hypothesis—Parasitoid of stem-boring Melanagromyza and Ophiomyia spp. Evidence—Griffiths (81); NMS (59). Comment—Recorded hosts: M. lappae , M. eupatorii , M. symphyti , M. fabae , M. astragali , M. moatesi , O. melandryi . [5]

DNA Barcode: Yes. [6]

Similar species: C. kirvus . [7]

Notes: C. cylindricus and didas are well separated by their barcodes, but less so by the morphological characters in Griffiths IV-682. Host records are supported by barcode sequences. [8]

[1] Taxonomy

We recognise 23 genera of European Dacnusini and note two more as incertae sedis. In general, we have taken a conservative view based on current practice, in the expectation that future DNA sequence data will complement morphological studies in resolving current uncertainties. Though we do not treat as formal taxa, the genera can be placed into two broad groups: the Dacnusa genus-group ( Amyras , Antrusa , Chaenusa , Chorebus , Coloneura , Coloneurella , Dacnusa , Exotela , Protochorebus , Protodacnusa , Tates , Terebrebus , Victorovita ) and the Coelinius genus-group ( Aristelix , Coelinidea , Coelinius , Epimicta , Eucoelinidea , Laotris , Polemochartus , Sarops , Synelix , Trachionus ).

We hope that all species in Fauna Europaea (2023) are mentioned in the checklist, those we believe no longer valid in square brackets. As of July 2024, the Fauna Europaea website has been unavailable for nine months so we have not been able to finally check this.

Note: Parts II and III of Griffiths’ monograph state a publication date of 1966 but they were actually published in 1967 ( Belokobylskij et al. 2003) which is the date we use here.

[2] Synonymy

A list is provided of published synonyms. One new synonym is established: Chorebus luzulae Griffiths syn. nov. is synonymised with Chorebus aphantus Marshall.

[3] Groups

There is not a settled intrageneric classification for the large genera Chorebus and Dacnusa . Species in the genera are assigned to informal groups with an alphanumeric code (1a, 2ci etc., defined at the beginning of the two genera) which are largely based on the work of Nixon, Griffiths and Tobias and some suggestions by the authors. Subgenera have been proposed in Chorebus and Dacnusa but are not used here (see Discussion) though we show how they align with the informal groups.

[4] Literature

The two most important treatments of European Dacnusini by Nixon (loc. cit.) and Griffiths (loc. cit.) are multipart works with no index. Neither covers the complete tribe. Complexities also arise because Nixon never finished his revision (the treatment of the Chorebus uliginosus group and Chaenusa was planned but never completed) and because Griffiths organized his work by host taxonomy so that treatment of one species can occur in multiple places.

An index is provided to the places in Nixon and Griffiths’ works where each species is treated. For Nixon the format is (i) Nixon 1937 -16 referring to page 16 of the 1937 volume (4) of the Transactions of the Society for British Entomology, and (ii) for the series of papers beginning in 1943, Nixon 1944 -143 (K 1943-165) where the species account appears on page 143 of the 1944 volume of the Entomologist’s Monthly Magazine and the species is keyed on page 165 of the 1943 volume (if the species is keyed very near the description in the same volume it is not referenced separately). Griffiths numbered the seven parts of his monograph I – VII and the format Griffiths IV-683 [VII-353] (K IV-682) is used which indicates the main species description is on page 683 of part IV, the species is keyed on page 682 of part IV and there is also a minor discussion of the species on page 353 of Part VII (the entry in square brackets).

Tobias (1986) provides keys in Russian to European Alysiinae including the large Dacnusini genera Chorebus and Dacnusa . These are largely based on Griffiths though with some modifications and the inclusion of a number of species described in the Russian literature (a few are also telegraphically described in the keys). This work was later translated into English ( Tobias 1995). Both versions have indexes though that in the English version is difficult to use as it uses the Russian-version pagination with the Russian page numbers being added in the margin. For species of the large genera Chorebus and Dacnusa , the couplet or couplets in which the species is treated is given in the format Tobias (45) or Tobias (56, 78).

[5] Hosts

Compared with many other groups of parasitoid wasps, there is relatively rich information about Dacnusini and Dapsilarthra genus-group host associations. Griffiths made extensive use of this in his revision and did the excellent service of reviewing all previous host associations, rejecting a very large percentage. Taxapad ( Yu et al. 2016) lists host associations from the literature but without critical appraisal and it contains many questionable associations, and so should be used with great caution.

A new approach ( Godfray 2021) is taken here to provide a summary of the different species’ host associations which is designed to be of use to non-specialists. Where data is available, host range is summarized as an explicit Hypothesis to emphasise the provisional nature of our biological knowledge. The hypothesis is followed by a statement of the Evidence in its support. A fairly high bar is set for admissible evidence typically requiring voucher specimens. Figures are given for the number of reared specimens recorded by Griffiths, in the National Museum of Scotland database of reared Dacnusini maintained by the first author (as of mid 2024), and by other authors (though further records are not common). Thus “ Evidence —Griffiths (81); NMS (59)” indicates 81 records listed by Griffiths and 59 in the NMS database. Care has been taken to avoid double-scoring. This quantitative information is helpful in judging the strength of evidence underlying the stated hypothesis. A final Comments statement provides any further details helpful in interpreting the hypothesis and often specific host associations if not stated in the hypothesis statement.

All hosts belong to the dipteran family Agromyzidae unless explicitly stated otherwise (and Chromatomyia is treated as a synonym of Phytomyza following Winkler et al. (2009)).

[6] DNA Barcodes

Work is underway to create a DNA Barcode (the sequence of part of the mitochondrial CO1 gene) library for European Dacnusini . A species is said to have a DNA Barcode if a “barcode compliant” sequence is present in BOLD (Barcode of Life Database; http://v4.boldsystems) to which a BIN (Barcode Index Number ) has been assigned. For reasons given in the Discussion we do not give the BIN indices themselves, but sequence data can be found in BOLD by searching for the Linnean binomial (a majority but not all sequences are in the public domain). The application of all European Dacnusini names in BOLD have been reviewed and (at July 2024) are compliant with this checklist.

[7] Similar species

The most recent keys to the majority of genera of European Dacnusini are in Griffiths (1964; 1967a; 1967b; 1967c; 1968a; 1968b). Griffiths (1984) described a few more species and about 70 species have been described since by various authors. For species described after Griffiths’ work in the 1960s we note as a “Similar species” the nearest taxa included in Griffiths’ keys, typically based on the judgement of the new species’ author. The new species is also listed as a “Similar species” under the nearest species keyed by Griffiths. In the absence of an up-to-date key it is hoped that this will alert workers to the presence of post-Griffiths taxa. Similar species are also noted, where possible, in Chaenusa and Coelinidea but these genera lack a 20 th or 21 st century revision and these associations should be viewed as provisional.

[8] Notes

The final section includes any further relevant information, for example a species significance in pest management or references to morphological or autecological treatments.

We have not attempted to provide information on geographical distribution. There are 21 st century critical national checklists for Germany ( Belokobylskij et al. 2003), Finland ( Koponen et al. 2016), Denmark ( Peris-Felipo et al. 2016a), the United Kingdom ( Godfray 2021), Russia (distinguishing European Russia) ( Alekseev et al. 2019) and Spain ( Docavo et al. 2006) while Fauna Europaea summarises literature records for all European countries (though must be interpreted cautiously as the literature has many misidentifications and currently (July 2024) is offline).