Effect of Gold Nanoparticles Against Tetranychus urticae and Phytoseiulus persimilis in Tomato

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript currently lacks a clearly defined central message and does not adequately highlight the novelty of the work. The over-reliance on complex tables without sufficient narrative explanation makes it difficult to interpret the results. Discussions on plant physiological responses and ROS seem unrelated to the core objective and could be moved to supplementary materials or omitted. The conclusion should be shortened and focused to clearly state the main findings and implications. We recommend substantial restructuring to enhance clarity, relevance and scientific impact.

 

My Comments

1. Title is really confusing, based on title I am unable to see the discoverability of this research work, title should be focused clear, as the inclusion of “agronomic variables” in the title dilutes the central message, If the study is primarily about nanoparticles effects on pest and predator, agronomic performance should be a secondary concern. Also, grouping mortality and repellency for both species T. urticae (a pest) and P. persimilis (a predator) is problematic unless both effects were equally tested in both species.
2. Abstract is lack of key research results, authors should clearly indicate key findings, as per my suggestion, author should mainly focus on key results regrading AuNPs on mites rather than focusing on agronomic traits which could be a supplementary material to support AuNPs effects on crop health. I suggest to remove agronomic traits, if not central to the study aim. Authors need to structure a well-defined abstract, with research significance, method, key results and future recommendations. Also avoid to use uncharacterized terms, not all readers will immediately understand IRAC protocol 004, °Brix, or lethal-time analysis.
3. The introduction offers extensive background but lacks conciseness. All the paragraphs reiterate known information’s to AuNPs in plants broadly. Furthermore, the introduction could benefit from framing a testable hypothesis. Also introduction followed by a long list of causes and citations that overlap conceptually. Better to streamline one or two most relevant and latest citations per concept and avoid stacking too many references. Also, author remain unable to justify the novelty of this research. Authors should clearly states, what is new about gold nanoparticles (AuNPs) here? What are the gaps that are still understood and how does this study address these gaps?
4. Material and methods: Authors should separate the insect rearing conditions or their sources, mixing them in experiment treatment section looks so vague. Make a separate section (first section) and explain both mite’s species rearing conditions and from where these motes were sourced.

Authors used sodium dioctyl sulfosuccinate (DSS) as a dispersant, how does this chemical affect mite’s life history parameters? Author must provide data. Line 126, how did you removed solution, does removing solution also removed NPs from the leaves discs? How long you wait to make leaf disc to get dry, or you released mites on wet leaf discs?

Line 128: Selected mites were male or females? Also for repellency tests which sex of mites you used?

Why you choose only T. urticae for greenhouse evaluations? Why not P. persimilis?

5. Results: Authors presents the results exclusively in table format without accompanying narrative explanations or visual summaries such as figures or graphs. This data-dense presentation makes it difficult to interpret and extract key findings efficiently. Including a clear textual description of the main trends and patterns, along with selected visualizations (e.g., bar charts, heatmaps), would greatly enhance readability and improve the accessibility of the results.

For AuNPs characterization, I would suggest to add at least 3 pictures of TEM, with different size resolution, to see the clear patterns of AuNPs.

Table 2. All the tested concentrations of AuNPs showed a consistent significance patterns across egg hatching and mortality % of different life history stages of T. urticae. This level of uniformity across treatments and developmental stages is quite striking. Could the authors clarify how such consistent significance patterns were achieved? Were there any biological or experimental factors such as concentration thresholds, nanoparticle stability or uniform exposure conditions that contributed to this uniformity?

Results section 3.5 (Repellency of AuNPs on T. urticae): This section is dense, overly detailed, and hard to follow due to the excessive use of numerical data, repetition and switching between repellency percentages, repellency index (RI) and statistical significance without clear summarization or structure. Highlight only the most notable significant differences in the main text. Similarly, for section 3.6.

While the inclusion of plant physiology parameters affected by AuNPs is scientifically valuable, it seems to divert attention from the central objective of this study, which is to assess the acaricidal and behavioral effects of AuNPs. The detailed plant-based data may therefore be more appropriately placed in the supplementary materials.

 

6. There is no clear separation between results and discussion. Lines 626–629: The discussion highlights effects of AuNPs on plant physiological parameters; however, no data are presented on AuNP accumulation, translocation, or movement within plant tissues. Without such evidence, the claim about direct physiological effects remains speculative. The authors should either clarify the basis for this statement or revise it to avoid over-interpretation of the observed plant responses.

Line 640-649: Same issue persist; The discussion includes content related to reactive oxygen species (ROS), which appears to be outside the main scope of the study.

7. The conclusion section is overly long and contains excessive detail, making it difficult for readers to clearly grasp the main findings and overall message of the study. I recommend condensing this section to highlight only the most critical results and implications, aligned with the primary objectives of the work.
8. No heading for table 8.

Comments on the Quality of English Language

My Comments

1. Title is really confusing, based on title I am unable to see the discoverability of this research work, title should be focused clear, as the inclusion of “agronomic variables” in the title dilutes the central message, If the study is primarily about nanoparticles effects on pest and predator, agronomic performance should be a secondary concern. Also, grouping mortality and repellency for both species T. urticae (a pest) and P. persimilis (a predator) is problematic unless both effects were equally tested in both species.
2. Abstract is lack of key research results, authors should clearly indicate key findings, as per my suggestion, author should mainly focus on key results regrading AuNPs on mites rather than focusing on agronomic traits which could be a supplementary material to support AuNPs effects on crop health. I suggest to remove agronomic traits, if not central to the study aim. Authors need to structure a well-defined abstract, with research significance, method, key results and future recommendations. Also avoid to use uncharacterized terms, not all readers will immediately understand IRAC protocol 004, °Brix, or lethal-time analysis.
3. The introduction offers extensive background but lacks conciseness. All the paragraphs reiterate known information’s to AuNPs in plants broadly. Furthermore, the introduction could benefit from framing a testable hypothesis. Also introduction followed by a long list of causes and citations that overlap conceptually. Better to streamline one or two most relevant and latest citations per concept and avoid stacking too many references. Also, author remain unable to justify the novelty of this research. Authors should clearly states, what is new about gold nanoparticles (AuNPs) here? What are the gaps that are still understood and how does this study address these gaps?
4. Material and methods: Authors should separate the insect rearing conditions or their sources, mixing them in experiment treatment section looks so vague. Make a separate section (first section) and explain both mite’s species rearing conditions and from where these motes were sourced.

Authors used sodium dioctyl sulfosuccinate (DSS) as a dispersant, how does this chemical affect mite’s life history parameters? Author must provide data. Line 126, how did you removed solution, does removing solution also removed NPs from the leaves discs? How long you wait to make leaf disc to get dry, or you released mites on wet leaf discs?

Line 128: Selected mites were male or females? Also for repellency tests which sex of mites you used?

Why you choose only T. urticae for greenhouse evaluations? Why not P. persimilis?

5. Results: Authors presents the results exclusively in table format without accompanying narrative explanations or visual summaries such as figures or graphs. This data-dense presentation makes it difficult to interpret and extract key findings efficiently. Including a clear textual description of the main trends and patterns, along with selected visualizations (e.g., bar charts, heatmaps), would greatly enhance readability and improve the accessibility of the results.

For AuNPs characterization, I would suggest to add at least 3 pictures of TEM, with different size resolution, to see the clear patterns of AuNPs.

Table 2. All the tested concentrations of AuNPs showed a consistent significance patterns across egg hatching and mortality % of different life history stages of T. urticae. This level of uniformity across treatments and developmental stages is quite striking. Could the authors clarify how such consistent significance patterns were achieved? Were there any biological or experimental factors such as concentration thresholds, nanoparticle stability or uniform exposure conditions that contributed to this uniformity?

Results section 3.5 (Repellency of AuNPs on T. urticae): This section is dense, overly detailed, and hard to follow due to the excessive use of numerical data, repetition and switching between repellency percentages, repellency index (RI) and statistical significance without clear summarization or structure. Highlight only the most notable significant differences in the main text. Similarly, for section 3.6.

While the inclusion of plant physiology parameters affected by AuNPs is scientifically valuable, it seems to divert attention from the central objective of this study, which is to assess the acaricidal and behavioral effects of AuNPs. The detailed plant-based data may therefore be more appropriately placed in the supplementary materials.

 

6. There is no clear separation between results and discussion. Lines 626–629: The discussion highlights effects of AuNPs on plant physiological parameters; however, no data are presented on AuNP accumulation, translocation, or movement within plant tissues. Without such evidence, the claim about direct physiological effects remains speculative. The authors should either clarify the basis for this statement or revise it to avoid over-interpretation of the observed plant responses.

Line 640-649: Same issue persist; The discussion includes content related to reactive oxygen species (ROS), which appears to be outside the main scope of the study.

7. The conclusion section is overly long and contains excessive detail, making it difficult for readers to clearly grasp the main findings and overall message of the study. I recommend condensing this section to highlight only the most critical results and implications, aligned with the primary objectives of the work.
8. No heading for table 8.

Author Response

  clear                 12 / 5.000  

PDF ATTACHED

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This study valuably explores green-synthesized gold nanoparticles (AuNPs) for managing Tetranychus urticae and their effects on tomato agronomy. While the dual lab/greenhouse approach is robust, critical inconsistencies undermine conclusions:

1. At 175 mg L⁻¹, larval mortality is 98% (Table 2), but Table 3 reports LC₉₅=207 mg L⁻¹ – implying 95% mortality requireshigher concentration than 98% mortality. Please recheck Probit analysis parameters and raw mortality data for consistency.
2. The repellency formula (p.4) uses "Control population - Treatment population," but the experimental setup hasthree treated dishes + one control. How were populations pooled?
3. Abstract states AuNPs increased °Brix, but Table 12 shows:Fruit °Brix decreased with AuNPs (5.2°Bx at 1000 mg L⁻¹ vs. 6.3°Bx control). Fruit weight reduced (54.6 g vs. 54.5 g control). Please align abstract/conclusions with actual results or explain discrepancies.
4. LT assays evaluated up to 120 h (p.7), but some LT₉₀ values (e.g., protonymphs at 100 mg L⁻¹: 136 h) exceed the observation period.The authors should report censoring status or extend evaluation timeframe to capture full mortality.
5. Figures 1 (EDX) and 2 (TEM) are cited but not included in the text. Size (29.8 nm) and morphology claims cannot be verified.I encourage the authors provide images or detailed supplementary data for characterization.
6. Table 2 reports F-values up to 3214 (protonymphs) – implausibly high for biological data. Verify calculations.
7. In the Discussion (p.20), it is proposed that AuNPs reduce pest numbers by inducing plant defenses (e.g., ROS). However, the experiment lacked an AuNP-treated group without mite infestation, making it impossible to distinguish between direct toxicity and plant-induced resistance.I suggest either supplement with control experiments (e.g., AuNPs applied to non-infested plants) or qualify the conclusions as speculative.

General Recommendations:

(1) Cross-check all tables against raw data for consistency (critical for LC/LT values).

(2) Define "contentation" (p.5) as "concentration" and standardize "Forato®" to "Phorate" (Tables 4/6).

(3) Discuss practical implications of P. persimilis toxicity (SR=0.95) for IPM integration.

(4) Specify if control mortality was corrected via Abbott’s formula in all bioassays.

(5) Most of the scientific names of the species should be italic throughout the whole manuscript.

(6) Do the authors forget the title of the Table 8?

(7) The results presented by the authors only include tabular data. Could more comprehensive and vivid results be provided, such as phenotypic changes in plants after AuNP application (e.g., mite damage symptoms, visual indicators of yield and quality traits)?

Author Response

  PDF ATTACHED

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

1. The plots could be improved by clearly indicating statistically significant differences among treatments through the addition of letter groupings or asterisks. In their current form, it's difficult to identify significant relationships from the visual presentation.
2. The authors should include additional keywords to improve discoverability. A total of 6-8 keywords would be more appropriate, as the current 4 keywords are insufficient for adequate indexing
3.  Furthermore, The manuscript does not contain any specific recommendations (concentration, frequency, field relevance, etc.) on the AuNPs application. Since the study is wholly application-oriented, this information is critical if the findings are to inform future research.
4. The potential risks associated with nanoparticle accumulation in plant tissues have not been discussed. 

Comments on the Quality of English Language

English can be improved 

Author Response

1. The plots could be improved by clearly indicating statistically significant differences among treatments through the addition of letter groupings or asterisks. In their current form, it's difficult to identify significant relationships from the visual presentation.

Letter groupings were added to the repellency and biological efficacy charts.

2. The authors should include additional keywords to improve discoverability. A total of 6-8 keywords would be more appropriate, as the current 4 keywords are insufficient for adequate indexing

4 keywords were added.

3. Furthermore, the manuscript does not contain any specific recommendations (concentration, frequency, field relevance, etc.) on the AuNPs application. Since the study is wholly application-oriented, this information is critical if the findings are to inform future research.

Specific recommendations were generated for the use of AuNPs on T. urticae.

4. The potential risks associated with nanoparticle accumulation in plant tissues have not been discussed. 

Recommendations were added regarding the potential impact of these nanoparticles and additional studies to consider for future research.

Author Response File: Author Response.pdf