Molecular and Morphological Analyses for Delimiting Species Boundaries: The Case of Sclerodermus cereicollis Kieffer, 1904 (Hymenoptera: Bethylidae)^†

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Dr. Masini,

I have carefully read your manuscript entitled "Molecular and morphological analyses for delimiting species boundaries: the case of Sclerodermus cereicollis (Hymenoptera: Bethylidae)". The paper describes the study of Bethylidae previously associated with the name of S. cereicollis (and related species) in Europe and Africa. This study demonstrated that the African specimens actually belong to a new species, S. annobonensis.

However, I believe that this manuscript could be recommended for publication only after making substantial changes to the paper. Specifically, the authors did not list (and, consequently, did not use) any quantitative morphological technique to delimit different species among the taxa they studied (see, e.g.: https://doi.org/10.1093/sysbio/syr061). Consequently, species delimitation (and/or keys to species) can be subjective (see, e.g., lines 780-781 of the manuscript: "Metapectal-propodeal disc with lateral sides slightly (vs. strongly) divergent posterad"). On the contrary, the authors did employ molecular techniques, but the molecular study did not include the newly described S. annobonensis, and therefore these characters were not used to distinguish between S. cereicollis and the new species. I also have a number of other, mostly technical, suggestions that can be found in the attached PDF file.

Comments for author File: Comments.pdf

Author Response

We sincerely thank the reviewer for the time, effort, and valuable feedback provided in the evaluation of our manuscript. We have carefully considered all the comments and suggestions, and we believe that the revisions have significantly improved the clarity and quality of the paper.

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The “Introduction” is well structured and describes what the authors hoped to achieve accurately; it clearly states the problem being investigated: the identity of  Sclerodermus cereicollis of Jean-Jacques Kieffer. It summarizes relevant research providing context and explaining what other authors’ findings are being challenged and extended regarding the taxonomy in genus Sclerodermus. However, I have an impression that it uses quite some space to discuss ecology in Sclerodermus, addressing host preferences and potential of biological control, hence a substantial part of the “Introduction” appears off context, not well connnected to the actual results.

The “Materials and Methods” section accurately explains how the data was collected and the design is suitable for answering the question posed in terms of applying classical morphological treatment combined with molecular data in assistance for species IDs. The equipment and materials are adequately described and, in addition, are reinforced by thirteen figures grouped in three assemblages, which further points out that they were precise in describing measurements.

The “Results” section is the most essential in the work. It is well arranged but some points are missing. At first, in the diagnosis for S. cereicollis (lines 263-263), the specific characters are far from being enough for unique ID; and moreover, no one close species was treated here. This is a serious omission; thus, I insist for further, detailed assessment of unique morphological characters and quotation of at least two closely related species described before here. Similar presence of data on this subject is found further in the “Discussion” section (rows 696-721 & fugure 14) which proper place is not there at all. At second, there is diagnosis for the newly described Sclerodermus annobonensis; similar presence of data on this subject is found again in the “Discussion” section (rows 756-768 & fugure 15) which is not a proper place for it. I have identified in this section also some weaknesses that need to be improved before the paper is published: there is a number of inaccuracies in the description of various structures (some of them are indicated in the detailed comments separately), some therms of the structure not completely correspond to the nomenclature of the integument sculpture presented by Rick Harris (the literature source quoted in the “Material and methods”), and the setation is presented in the description pralelly with the tegument structure (as far as the setae and hairs are additional structures, they must be characterized in their own section apart from the tegument structure as the color and measurements are).

The “Discussion” and “Conclusion” are quite descriptive but could be deepened to address the initial assumption about the reasons for separating a new species (Sclerodermus annobonensis) from the syntype series of S. cereicollis.

The “Abbreviations” should take place in the “Materials and Methods” section.

In general, the MS presents useful and detailed insights in Scleroderus taxonomy and I would suggest to accept it for publication after consideration to the mentioned remarks.

Some detailed comments:

Line 3. I propose to change the title in the following manner: “Sclerodermus cereicollis Kieffer, 1904 instead of “Sclerodermus cereicollis”; this would indicate that the work is dealing with long time ago described species which needs to go under taxonomic revision including lectotype designations, new species description amidst the syntypes and so on.

            Lines 14-15. “80 species of idiobiont ectoparasitoids of insect pests in forests”: even though, it could be expected, there are no evidences that all of the described species have to stand under the biological traces of “idiobiont ectoparasitoids”, moreover, most of the biology of the described species within the genus is completely unknown – so I would like to ask for changing the sentence here in concordance to the present (real) state of knowledge in Sclerodermus.

            Lines 37-39. Again, the same blatant mistake “These wasps are idiobiont ectoparasitoids of immature stages of insects belonging to the orders Coleoptera, Lepidoptera, and Isoptera” – in the quated sorce only one (number 4) presents original information for the biology of any Sclerodermus. I find inappropriate to state so flippantly the biological traits for the genus.

Lines 164-169. Avoid use of capital letters in abbreviation explanations for figure 3. (Is it neesairly to state these explanantions at all ?; they were already mentioned in other parts in the text: lines 140-152.).

            Line 247. “in” not in Italic; “Ficus carica” in Italic.

            Line 258. Avoid “(Pascoe, 1857)” after the species group name.

            Lines 320-321. The description of color of the mesosoma does not correspond to the pictures below: at least mesoscutum, mesoscutellum, and mesopleuron are dark (blackish).

            Lines 327-328. The description of shape of the head does not correspond to the picture abobe (6c): it is elongated oval rather than globoid.

            Line 338. Make clear about the length of the pedicell: longer than which one of the flagellomeres (or combined length of group of flagellomeres).

Line 344. The description of shape of the mesoscutellum does not correspond to the picture above (6f): it is trapezoidal rather than equilateral triangle-shaped.

Line 380-381. Make clear about the length of the pedicell: longer than which one of the flagellomeres (or combined length of group of flagellomeres).

Line 381-382. The description of length of the flagellomeres does not correspond to the picture below (7d): at least flagellomere 2 and 3 are equal in length and width.

Author Response

We sincerely thank the reviewer for the time, effort, and valuable feedback provided in the evaluation of our manuscript. We have carefully considered all the comments and suggestions, and we believe that the revisions have significantly improved the clarity and quality of the paper.

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Dr. Masini,

I have carefully read an updated version of your manuscript entitled "Molecular and morphological analyses for delimiting species boundaries: the case of Sclerodermus cereicollis (Hymenoptera: Bethylidae)". I believe the paper is substantially improved now, and it can be published in Diversity. However, I still have a few technical suggestions aiming to improve the text (please see the attached file). 

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf