The Phenotypic Landscape of Phloeosinus baumanni: Spatial Patterns of Morphological Variation and Their Implications for Ecology and Taxonomy

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors and Editors,

Dear Authors and Editors
The genus Phloeosinus comprises nearly 90 species found in the Holarctic, Oriental and Australian regions.
Some species exhibit subtle intraspecific differences. Studies on the variation of phenotypic traits influenced by environmental factors are always valuable for taxonomic reasons.
The paper is carefully prepared, from the objectives through the methodology to the presentation of the results.
The data from the appendix could be incorporated into the text or the references clearly highlighted.
Minor editorial comments have been marked on the typescript.
I would only suggest expanding, either in the discussion or the introduction, the section on Ph. variolatus to include a comparison of taxonomic differences between the species.

Best regards

Comments for author File: Comments.pdf

Author Response

Response to Reviewers’ Comments

Manuscript title: The phenotypic landscape of Phloeosinus baumanni: spatial patterns of morphological variation and their implications for ecology and taxonomy

Dear Academic Editor and Reviewers,

Thank you very much for taking the time to review our manuscript. We sincerely appreciate the positive evaluation and constructive comments provided by both reviewers. We have revised the manuscript accordingly, and the corresponding corrections have been highlighted using track changes in the resubmitted files. Below, we provide a detailed point-by-point response to each comment, indicating the specific changes made and where they can be found in the revised manuscript.

1. Summary

We revised the manuscript to improve clarity, consistency, and taxonomic context. Specifically, we expanded the comparison with Phloeosinus variolatus, clarified the citation of supplementary material, completed the Hopkins reference, corrected minor editorial and grammatical issues, reduced repetitive sentences in the Introduction and Discussion, strengthened the biological interpretation of morphometric variation, and emphasized that our conclusions remain strictly phenotypic.

2. Questions for General Evaluation

Reviewer’s Evaluation: The reviewers considered the manuscript well prepared, statistically sound, clearly organized, and valuable for bark beetle systematics, phenotypic variation, and morphology-based species delimitation.

Response and Revisions: We thank the reviewers for their positive evaluation. We maintained the overall structure of the manuscript and revised specific sections to improve clarity, consistency, and biological interpretation. The main changes are detailed below in the point-by-point responses.

3. Point-by-point response to Comments and Suggestions for Authors

Response to Reviewer 1

Comments 1: The genus Phloeosinus comprises nearly 90 species found in the Holarctic, Oriental and Australian regions.

Response 1: Thank you for this comment. We retained the taxonomic and biogeographic context of Phloeosinus in the Introduction.

Lines 59–64: We retained and clarified the general information on the distribution, diversity, and forestry relevance of Phloeosinus. This was done to keep the manuscript framed within the broader taxonomic and biogeographic context of the genus.

 

Comments 2: Some species exhibit subtle intraspecific differences. Studies on the variation of phenotypic traits influenced by environmental factors are always valuable for taxonomic reasons.

Response 2: We agree with this comment. We revised the Introduction to make the taxonomic importance of intraspecific phenotypic variation clearer.

Lines 108–126: We condensed and revised the section discussing intraspecific morphological variability, sexual dimorphism, locality-associated variation, and the risk of inaccurate interpretations of species boundaries. This change was made to better explain why subtle phenotypic differences should be evaluated within a broader intraspecific framework before assigning them taxonomic value.

Comments 3: The paper is carefully prepared, from the objectives through the methodology to the presentation of the results.

Response 3: We sincerely thank the reviewer for this positive assessment. The general structure of the manuscript was maintained, but several corrections were made to improve consistency between the methods, tables, and results.

Lines 146–148: The number of analyzed specimens was corrected to 254 adult specimens, including 128 females and 126 males, from 21 localities in Mexico and Guatemala. This change was made to make the text consistent with the revised dataset and Table 1.

Lines 224–227: The sentence describing data collection with tpsDig2 was rewritten. The previous wording was unclear, so we clarified that Cartesian coordinates of spatially homologous points and the scale bar were recorded using tpsDig2.

Lines 309–313 and 336–338: Dataset abbreviations were standardized as Non-Dimorp, Mal-Dimorp, and Fem-Dimorp. This change was made to avoid confusion among the three datasets used in the geographic analyses.

Comments 4: The data from the appendix could be incorporated into the text or the references clearly highlighted.

Response 4: Thank you for this suggestion. We kept the detailed statistical outputs in the supplementary material because incorporating them into the main manuscript would make the text too long. However, we highlighted the supplementary material more clearly in the main text.

Lines 353–357: We added a citation to Supplementary Fig. A1 in the Methods section, where the PCoA biplot used to select the variables is described. This was done to make clear where the biplot supporting variable selection can be found.

Lines 464–469: Table S1 and Table S2 were cited in the Results section when reporting locality-level differences for non-sexually dimorphic and sexually dimorphic traits. This was done to connect the supplementary statistical tables directly with the results described in the main text.

 

Lines 479–481: Supplementary Fig. A1 was cited again in the Results section when discussing the variables contributing most to the principal coordinate analyses. This was done to make the link between the supplementary figure and the interpretation of the ordination analyses explicit.

Reference 16: The Hopkins reference was completed. In the previous version, it appeared only as “Hopkins, A.D. Notes on Some Mexican Scolytidae: With Descriptions of Some New Species; 1905.” In the revised manuscript, it was changed to “Hopkins, A.D. Notes on Some Mexican Scolytidae: With Descriptions of Some New Species; United States Department of Agriculture, Bureau of Entomology: Washington, DC, USA, 1905.” This change was made to provide the complete bibliographic information for the original taxonomic source.

Comments 5: Minor editorial comments have been marked on the typescript.

Response 5: We thank the reviewer for the editorial comments marked on the manuscript. We addressed these comments throughout the revised version.

Lines 224–227: The unclear phrase related to tpsDig2 was corrected to improve grammar and methodological clarity.

Lines 328–329 and 336–338: Abbreviation inconsistencies were corrected to standardize the use of Non-Dimorp, Mal-Dimorp, and Fem-Dimorp.

Lines 353–357: The sentence describing the selection of variables from the PCoA biplot was clarified and linked to Supplementary Fig. A1.

Lines 464–469: The duplicated phrase “From the univariate perspective” was removed, and the paragraph was rewritten to improve clarity.

Reference 16: The incomplete Hopkins reference was corrected and completed.

Comments 6: I would only suggest expanding, either in the discussion or the introduction, the section on Ph. variolatus to include a comparison of taxonomic differences between the species.

Response 6: Thank you for this important suggestion. We expanded the section on Phloeosinus variolatus in both the Introduction and the Discussion.

Lines 73–97: We expanded the Introduction to compare P. baumanni with morphologically similar species, particularly P. variolatus and P. cupressi. We added that these species share similar elytral sculpture patterns and host associations, and that their separation has traditionally relied on subtle external characters, including crenulations and tubercles on the elytral disc and declivity, vestiture density, and other external traits. This change was made to provide a clearer taxonomic context for the comparison with P. variolatus.

Lines 659–681: We expanded the Discussion to explain why the comparison with P. variolatus is relevant. We added that some diagnostic traits traditionally used in Phloeosinus, especially elytral sculpture, declivity ornamentation, and vestiture, may show overlapping variation. We also clarified that the distinction between P. baumanni and P. variolatus has traditionally depended on subtle differences in body proportions, pronotal sculpture, and elytral characters. This change was made to emphasize that the observed variability in P. baumanni should be evaluated within an intraspecific framework before assigning taxonomic significance.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

the manuscript titled: The phenotypic landscape of Phloeosinus baumanni: spatial patterns of morphological variation and their implications for ecology and taxonomy, addresses phenotypic variation and sexual dimorphism in Phloeosinus baumanni across a broad geographic range in Mexico and Guatemala. The study is well designed, statistically sound, and provides useful information for taxonomy and morphology, based species delimitation in Scolytinae, furthermore, the work represents a valuable contribution to bark beetle systematics and phenotypic variation. The text is generally clear, and the conclusions are supported by the data. In general, the sampling effort is extensive, including numerous specimens from many localities and biogeographic provinces, which provides robustness to the analyses. The integration of univariate and multivariate approaches is appropriate that support the interpretation of phenotypic variability. The manuscript clearly distinguishes sexual dimorphism from geographic variation, avoiding taxonomic mistakes. The SEM images are very very good and morphological characterization are detailed and useful for future comparative studies. The manuscript is well written and very good organized.

Suggestions: some sentences of the Introduction and Discussion are somewhat repetitive, especially regarding the importance of geographic variation and the risks of taxonomic overestimation. A moderate reduction would improve readability. The manuscript would benefit from a clearer biological interpretation of some morphometric differences. In several cases, the discussion remains descriptive and could better explain possible ecological or evolutionary drivers. The authors suggest the possible existence of differentiated lineages, but no molecular evidence is included. This is correctly acknowledged, though the manuscript could further emphasize that conclusions remain strictly phenotypic.

Some stylistic and grammatical issues remain throughout the text:

-occasional repetition (“from the univariate perspective..” appears twice consecutively around lines 424-425),

-minor inconsistencies in abbreviations (e.g., Non-Dimorp/Fem-Dimor),

-some long sentences that could be simplified for clarity,

-check consistency of figure and table citations throughout the manuscript. verify Figure 6, which is currently not visible and appears only as a blue box. Verify formatting of references and spacing in several sections.

-Ensure all supplementary tables and figures are properly cited in the text.

 

 

Author Response

Response to Reviewers’ Comments

Manuscript title: The phenotypic landscape of Phloeosinus baumanni: spatial patterns of morphological variation and their implications for ecology and taxonomy

Dear Academic Editor and Reviewers,

Thank you very much for taking the time to review our manuscript. We sincerely appreciate the positive evaluation and constructive comments provided by both reviewers. We have revised the manuscript accordingly, and the corresponding corrections have been highlighted using track changes in the resubmitted files. Below, we provide a detailed point-by-point response to each comment, indicating the specific changes made and where they can be found in the revised manuscript.

1. Summary

We revised the manuscript to improve clarity, consistency, and taxonomic context. Specifically, we expanded the comparison with Phloeosinus variolatus, clarified the citation of supplementary material, completed the Hopkins reference, corrected minor editorial and grammatical issues, reduced repetitive sentences in the Introduction and Discussion, strengthened the biological interpretation of morphometric variation, and emphasized that our conclusions remain strictly phenotypic.

2. Questions for General Evaluation

Reviewer’s Evaluation: The reviewers considered the manuscript well prepared, statistically sound, clearly organized, and valuable for bark beetle systematics, phenotypic variation, and morphology-based species delimitation.

Response and Revisions: We thank the reviewers for their positive evaluation. We maintained the overall structure of the manuscript and revised specific sections to improve clarity, consistency, and biological interpretation. The main changes are detailed below in the point-by-point responses.

3. Point-by-point response to Comments and Suggestions for Authors

Response to Reviewer 2

Comments 1: The manuscript titled “The phenotypic landscape of Phloeosinus baumanni: spatial patterns of morphological variation and their implications for ecology and taxonomy” addresses phenotypic variation and sexual dimorphism in Phloeosinus baumanni across a broad geographic range in Mexico and Guatemala. The study is well designed, statistically sound, and provides useful information for taxonomy and morphology-based species delimitation in Scolytinae; furthermore, the work represents a valuable contribution to bark beetle systematics and phenotypic variation. The text is generally clear, and the conclusions are supported by the data. In general, the sampling effort is extensive, including numerous specimens from many localities and biogeographic provinces, which provides robustness to the analyses. The integration of univariate and multivariate approaches is appropriate and supports the interpretation of phenotypic variability. The manuscript clearly distinguishes sexual dimorphism from geographic variation, avoiding taxonomic mistakes. The SEM images are very good, and the morphological characterization is detailed and useful for future comparative studies. The manuscript is well written and very well organized.

Response 1: We sincerely thank the reviewer for the positive evaluation of our manuscript and for recognizing the relevance of the sampling effort, the statistical approach, the distinction between sexual dimorphism and geographic variation, and the usefulness of the SEM images. We revised the manuscript following the reviewer’s suggestions to improve clarity, reduce repetition, strengthen the biological interpretation, and make the phenotypic scope of our conclusions more explicit.

Lines 108–126: The Introduction was revised to reduce repetition and improve the conceptual framing of intraspecific morphological variation, sexual dimorphism, locality-associated variation, and taxonomic interpretation. This change was made to improve readability while retaining the theoretical basis of the study.

Lines 646–657: A concise biological interpretation was added to the Discussion. This change was made to better explain the possible biological meaning of the morphometric differences observed in P. baumanni.

Lines 689–701: The Conclusion was revised to explicitly state that the results should be interpreted strictly within a phenotypic framework. This change was made to avoid overinterpreting the data as evidence for or against lineage differentiation.

Comments 2: Some sentences of the Introduction and Discussion are somewhat repetitive, especially regarding the importance of geographic variation and the risks of taxonomic overestimation. A moderate reduction would improve readability.

Response 2: We agree with this comment. We revised repetitive sections in both the Introduction and Discussion.

Lines 108–126: The Introduction was condensed. The previous version contained several consecutive sentences repeating the importance of geographic variation, stability of diagnostic characters, and the risk of taxonomic overestimation. We revised this section into a more concise paragraph that preserves the main ideas and references while improving readability.

Lines 630–645: The Discussion was revised to reduce repetitive statements about the taxonomic implications of geographic and sexual variation. This change was made so that the discussion moves more clearly from the observed phenotypic patterns to their biological and taxonomic interpretation.

Comments 3: The manuscript would benefit from a clearer biological interpretation of some morphometric differences. In several cases, the discussion remains descriptive and could better explain possible ecological or evolutionary drivers.

Response 3: Thank you for this important suggestion. We added a biological interpretation of the morphometric differences detected in P. baumanni, while avoiding unsupported causal claims.

Lines 646–653: We added that the morphometric variation observed in P. baumanni may reflect phenotypic responses associated with local conditions during host colonization, rather than fixed morphological discontinuities. This change was made to move beyond a purely descriptive interpretation of the results.

Lines 650–653: We added that, in bark beetles, host quality, colonized tissue, larval development, and environmental conditions can influence adult size and external structures. This change was made to provide a clearer biological explanation for variation in cephalic proportions and elytral sculpture.

Lines 654–657: We added that these factors were not directly tested and that no molecular data were included. This change was made to clarify that the proposed explanation should be interpreted as a biologically plausible hypothesis rather than as a demonstrated mechanism.

Comments 4: The authors suggest the possible existence of differentiated lineages, but no molecular evidence is included. This is correctly acknowledged, though the manuscript could further emphasize that conclusions remain strictly phenotypic.

Response 4: We agree with this comment. We revised the Discussion and Conclusion to emphasize that our conclusions remain strictly phenotypic.

Lines 654–657: We added that, because local factors were not directly tested and no molecular data were included, the results should be interpreted strictly as phenotypic evidence and as a basis for future integrative evaluation. This change was made to prevent overinterpretation of the morphological patterns.

Lines 689–701: The Conclusion was revised to clarify that the absence of clear morphological discontinuities does not support recognizing discrete groups based only on the analyzed characters, but also that our conclusions should not be considered formal evidence for or against lineage differentiation. This change was made to explicitly limit the scope of the conclusions to phenotypic evidence.

Lines 697–701: We added that molecular, phylogeographic, and ecological data will be essential to better understand the processes underlying the observed patterns of variation. This change was made to reinforce the need for future integrative studies.

Comments 5: Some stylistic and grammatical issues remain throughout the text: occasional repetition (“from the univariate perspective...” appears twice consecutively around lines 424–425).

Response 5: We corrected this repetition in the Results section.

Lines 464–469: The duplicated phrase “From the univariate perspective” was removed. The paragraph was rewritten to state only once that the number of crenulations on the edge of the elytral disc was the only non-sexually dimorphic variable that did not differ significantly among localities, and that NTIE3 and NTIE1 were comparatively homogeneous in both subsets. This change was made to remove redundancy and improve clarity.

Comments 6: Minor inconsistencies in abbreviations (e.g., Non-Dimorp/Fem-Dimor).

Response 6: We standardized the dataset abbreviations throughout the manuscript.

Lines 309–313: The abbreviations used to define the three datasets were standardized as Non-Dimorp, Mal-Dimorp, and Fem-Dimorp. This change was made to avoid confusion when distinguishing non-sexually dimorphic traits from sexually dimorphic traits in males and females.

Lines 336–338: The same abbreviations were standardized in the section describing locality-level analyses within the Transmexican Volcanic Belt. This change was made to ensure consistency between the general dataset definition and the geographic analyses.

Comments 7: Some long sentences that could be simplified for clarity.

Response 7: We revised several long sentences throughout the manuscript to improve clarity.

Lines 108–126: The Introduction was simplified by condensing several repetitive sentences about intraspecific variability, geographic variation, and taxonomic overestimation into a clearer and more concise paragraph.

Lines 224–227: The sentence describing the use of tpsDig2 was rewritten. This change was made to clarify the methodological procedure used to record Cartesian coordinates and the scale bar.

Lines 646–657: The new biological interpretation was written as a concise paragraph to avoid adding unnecessary length to the Discussion while still addressing the reviewer’s request.

Lines 659–681: The section comparing P. baumanni with P. variolatus was revised to improve clarity and taxonomic interpretation.

 

Comments 8: Check consistency of figure and table citations throughout the manuscript. Verify Figure 6, which is currently not visible and appears only as a blue box.

Response 8: We checked figure and table citations throughout the manuscript and corrected inconsistencies.

Lines 416–419: The citation to Fig. 4 was checked and corrected to ensure that all figure panels are cited consistently.

Lines 464–469: Table S1 and Table S2 were checked and cited where the corresponding statistical results are discussed.

Lines 479–481: Supplementary Fig. A1 was cited where the contribution of variables to the PCoA analyses is discussed.

Figure 6: Figure 6 was checked and reinserted in the revised manuscript to ensure that it is properly displayed rather than appearing as a blue box. This change was made to correct the visualization problem noted by the reviewer.

Comments 9: Verify formatting of references and spacing in several sections.

Response 9: We revised reference formatting and spacing throughout the manuscript.

Reference 16: The Hopkins reference was completed. The previous version listed the reference incompletely as “Hopkins, A.D. Notes on Some Mexican Scolytidae: With Descriptions of Some New Species; 1905.” In the revised manuscript, it now reads: “Hopkins, A.D. Notes on Some Mexican Scolytidae: With Descriptions of Some New Species; United States Department of Agriculture, Bureau of Entomology: Washington, DC, USA, 1905.” This change was made to provide the complete bibliographic information for the original description of P. baumanni.

Throughout the manuscript: We revised spacing in tables, figure legends, and sections affected by editorial corrections. This change was made to improve formatting consistency.

Comments 10: Ensure all supplementary tables and figures are properly cited in the text.

Response 10: We checked the supplementary material and ensured that all supplementary tables and figures are cited in the main text.

Lines 353–357: Supplementary Fig. A1 was cited in the Methods section, where the PCoA biplot used to select variables is described. This change was made to connect the supplementary figure directly with the methodological procedure.

Lines 464–469: Table S1 and Table S2 were cited in the Results section when reporting locality-level differences for non-sexually dimorphic and sexually dimorphic traits. This change was made to connect the supplementary statistical tables with the results described in the main text.

Lines 479–481: Supplementary Fig. A1 was cited again in the Results section when discussing the variables contributing most to the principal coordinate analyses. This change was made to ensure that the supplementary figure is clearly referenced where its results are interpreted.

4. Response to Comments on the Quality of English Language

Point 1: Some stylistic and grammatical issues remain throughout the text.

Response 1: We revised the manuscript to improve grammar, clarity, and readability. Several long or unclear sentences were simplified, duplicated wording was removed, abbreviations were standardized, and figure/table citations were checked. These changes can be found throughout the revised manuscript, especially in lines 108–126, 224–227, 309–313, 336–338, 464–469, and 646–681.

5. Additional clarifications

We thank the Academic Editor and both reviewers again for their careful reading and constructive comments. We believe that the revised manuscript is clearer, more concise, and better framed in terms of its taxonomic, biological, and strictly phenotypic scope.

Sincerely,

Francisco Armendariz-Toledano, on behalf of all co-authors