Insecticidal and Residual Effects of Spinosad, Alpha-Cypermethrin, and Pirimiphos-Methyl on Surfaces Against Tribolium castaneum, Sitophilus granarius, and Lasioderma serricorne

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The work carried out by Agrafioti et al. on insecticidal and residual effects of Spinosad……is a well conducted study with defined objectives and has scientific merit for consideration of publication in Agriculture journal. However, I have few comments to authors for their consideration.

1. Line 41, could you please elaborate why it is difficult to register new products?
2. Although the writing is good, there are numerous places in the introduction it seems like the authors declare the aim of the study, for instance, Line 49, and Line 58. It would be better the authors avoid using terminologies like in this context, Based on this and so on.
3. Change similarly, to avoid redundancy in line 65 to ‘In addition’.
4. Line 97, change “which” to “which is a”.
5. Section 2.2. please provide references for the mode of action of insecticides.
6. Line 104, add ‘used’ for the control.
7. Line 109-110 please rewrite.
8. I understand the authors used 9cm diameter Petri dishes for the experiments. One question arising from that is, if twenty adults were used in a small, confined area, how did this effect the free movement of the insects and do the authors anticipate any variation in results per se if larger diameter dishes were used instead?
9. It is unclear from the methodology how were the food sources provided to the dishes, were they placed in center or spread across the dishes? Kindly mention them in the methods.
10. Line 135- 136 please check the sentence.
11. In section 2.5, it would be better to mention somewhere the study evaluated the residual efficacy of treated surfaces, this will improve the understanding of the readers.
12. It is unclear how 7 bioassays were conducted, starting with 0, 1, 2, 3, 4, and 5 months. Could you please explain clearly in the methods section?
13. Where the experiments conducted separately for assessing mortality at each time points? If not, what happened to the dead insects at each time point? Where they retained until 21 days of final observation?
14. Section 2.6. please mention the level of significance used for the analysis.
15. Line 156-158. Does it mean that for concrete the maximum mortality achieved was with Spinosad? So, what was the mortality ranges for other insecticides, which was the least effective?
16. Please check for italics of scientific names throughout manuscript, for eg. Line 168, 174…
17. Line 176 add ‘surfaces’ after ceramic, and in other places too.
18. In results, please provide statistical information for significance and non-significances in test wherever possible.
19. Why did the authors not perform analysis to show the differences among surfaces type for each insecticide tested?
20. In discussion line 352, the authors mention that porous structure was the limitation factor for not observing better mortality on concrete surface. Does this have something to do with locomotion of insects to pick more insecticides for species which are highly active especially on smooth surfaces?

Author Response

Manuscript Number: agriculture-3605200

Title: Insecticidal and residual effects of spinosad, alpha-cypermethrin, and pirimiphos-methyl on surfaces against Tribolium castaneum, Sitophilus granarius, and Lasioderma serricorne

Dear Editor,

Thank you for your letter regarding our paper entitled: “Insecticidal and residual effects of spinosad, alpha-cypermethrin, and pirimiphos-methyl on surfaces against Tribolium castaneum, Sitophilus granarius, and Lasioderma serricorne”. The comments of the reviewers are valuable and contribute greatly to the improvement of our work. In the following, we shall refer to these comments that, as you can see, have been addressed/incorporated.

I remain at your disposal should you need additional information.

Many thanks for your interest in our work.

Sincerely,

Paraskevi Agrafioti

Post-Doc Researcher

University of Thessaly

Laboratory of Entomology and Agricultural Zoology

Reviewer 1

The work carried out by Agrafioti et al. on insecticidal and residual effects of Spinosad……is a well conducted study with defined objectives and has scientific merit for consideration of publication in Agriculture journal. However, I have few comments to authors for their consideration.

REPLY: The authors would like to thank the reviewer for these comments and recommendations on improving the quality of the manuscript before resubmission. A revised version is submitted with the proposed corrections/additions addressed. A point-by-point reply to each comment/correction can be found below.

1. Line 41, could you please elaborate why it is difficult to register new products?

REPLY: Thank you for your comment. It is quite difficult to register a new product in the market due to regulatory issues. Most countries have strict regulations to ensure the safety of pesticides for human health, non-target species, and the environment. The data for registration are based on toxicological studies, environmental data, and several trials, which are demonstrated to control the target species. All these data take years to collect and analyze and should be submitted in a format that complies with detailed guidelines.

1. Although the writing is good, there are numerous places in the introduction it seems like the authors declare the aim of the study, for instance, Line 49, and Line 58. It would be better the authors avoid using terminologies like in this context, Based on this and so on.

REPLY: We have deleted these phrases.

1. Change similarly, to avoid redundancy in line 65 to ‘In addition’.

REPLY: Revised, see line 65.

1. Line 97, change “which” to “which is a”.

REPLY: Done, see line 97.

1. Section 2.2. please provide references for the mode of action of insecticides.

REPLY: We have included the references 42-44.

1. Line 104, add ‘used’ for the control.

REPLY: Done.

1. Line 109-110 please rewrite.

REPLY: Revised.

1. I understand the authors used 9cm diameter Petri dishes for the experiments. One question arising from that is, if twenty adults were used in a small, confined area, how did this effect the free movement of the insects and do the authors anticipate any variation in results per se if larger diameter dishes were used instead?

REPLY: Thank you for this comment. This type of petri dish has been used in several published studies. For this reason, we used the same dishes in our bioassays. Please see below the reference list:

• Lampiri E.; Losic D.; Athanassiou C.G. (2025). Insecticidal effect of graphene as surface treatment for the control of two major stored product insects. Journal of Stored Products Research, 112, 102632. https://doi.org/10.1016/j.jspr.2025.102632
• Lampiri E.; Agrafioti P.; Athanassiou C.G. (2023). Insecticidal effect of three insecticides applied on different surfaces for the control of three stored-product beetle species. Journal of Stored Products Research, 101, 102087. https://doi.org/10.1016/j.jspr.2023.102087
• Rumbos C.I.; Dutton A.C.; Athanassiou C.G. (2014). Efficacy of two formulations of pirimiphos-methyl as surface treatment against Sitophilus granarius, Rhyzopertha dominica, and Tribolium confusum. Journal of Pest Science 87, 507–519. https://doi.org/10.1007/s10340-014-0599-x
• Athanassiou C.G.; Rumbos C.I.; Sakka, M.; Potin, O.; Storm, C.; Dillon A.B. (2017). Delivering Beauveria bassiana with electrostatic powder for the control of stored-product beetles. Pest Management Science, 75, 1725-1736. https://doi.org/10.1002/ps.4522

1. It is unclear from the methodology how were the food sources provided to the dishes, were they placed in center or spread across the dishes? Kindly mention them in the methods.

REPLY: We added the phrase “in the center of the dish”, please see line 136.

1. Line 135- 136 please check the sentence.

REPLY: Done.

1. In section 2.5, it would be better to mention somewhere the study evaluated the residual efficacy of treated surfaces, this will improve the understanding of the readers.

REPLY: We have revised the subsection.

1. It is unclear how 7 bioassays were conducted, starting with 0, 1, 2, 3, 4, and 5 months. Could you please explain clearly in the methods section?

REPLY: Six bioassays were conducted in our experiment. We have revised it.

1. Where the experiments conducted separately for assessing mortality at each time points? If not, what happened to the dead insects at each time point? Where they retained until 21 days of final observation?

REPLY: All dishes were maintained in the chamber under stable conditions, as mentioned in lines 135-136. The experiments were conducted separately for each target species and storage interval.

1. Section 2.6. please mention the level of significance used for the analysis.

REPLY: Done, please see line 149.

1. Line 156-158. Does it mean that for concrete the maximum mortality achieved was with Spinosad? So, what was the mortality ranges for other insecticides, which was the least effective?

REPLY: The sentence was revised; please see lines 56-158.

1. Please check for italics of scientific names throughout manuscript, for eg. Line 168, 174…

REPLY: Done, see lines 168, 174, 184 and 191.

1. Line 176 add ‘surfaces’ after ceramic, and in other places too.

REPLY: Done.

1. In results, please provide statistical information for significance and non-significances in test wherever possible.

REPLY: Thank you for your comment. I recommend not presenting the statistical analysis in the results section, since it is more comprehensive for the reader.

1. Why did the authors not perform analysis to show the differences among surfaces type for each insecticide tested?

REPLY: Thank you for this remark. The objective of this study was to evaluate the overall efficacy of each insecticide over time across different surfaces rather than to conduct a detailed comparative analysis among surface types for each product.

1. In discussion line 352, the authors mention that porous structure was the limitation factor for not observing better mortality on concrete surface. Does this have something to do with locomotion of insects to pick more insecticides for species which are highly active especially on smooth surfaces?

REPLY: Indeed. The porous materials (concrete surface) can significantly reduce the availability of insecticide residues on the surfaces, as the active ingredient can be absorbed into the substrate. This limitation is particularly relevant for highly active species that rely on frequent movement across treated surfaces to pick up a lethal dose. Regarding the non-porous surfaces, such as metal or glass, insecticides tend to remain on the surface, increasing the possibility of contact and subsequent uptake, especially for mobile species. Therefore, the mobility of insects is critical for efficacy, and active insects may acquire more insecticide on smooth surfaces than on porous ones such as concrete, where reduced residue availability and possible limited contact may contribute to lower mortality rates.

Reviewer 2 Report

Comments and Suggestions for Authors

The Manuscript entitled ‘Insecticidal and residual effects of spinosad, alpha-cypermethrin, and pirimiphos-methyl on surfaces against Tribolium castaneum, Sitophilus granarius, and Lasioderma serricorne’ presents a comprehensive study on the efficacy of three insecticides against stored product beetles on different surfaces over a six-month period. The study is relevant to the field of stored product protection and addresses practical concerns related to pest management in agricultural commodities.

1. The study addresses a significant issue in agricultural storage, namely the long-term efficacy of insecticides on different surfaces. This is highly relevant to the journal's scope, which focuses on agricultural practices and pest management.
2. The authors have tested three different insecticides (spinosad, alpha-cypermethrin, and pirimiphos-methyl) on four different surfaces (concrete, metal, plastic, and ceramic) against three key stored product beetles. This comprehensive approach provides valuable insights into the practical application of these insecticides.
3. Long-term Study: The study spans six months, which is a substantial duration for evaluating residual efficacy. This long-term perspective is particularly valuable for understanding the practical applicability of these insecticides in real-world scenarios.
4. The results are presented in a highly detailed manner, with extensive numerical data in tables. However, the narrative summary of the results is somewhat lacking. The text could benefit from a more concise and clear summary of key findings for each species tested, especially highlighting the most significant trends and differences observed across insecticides and surfaces.
5. While the Kruskal-Wallis H-Test was used to analyze the data due to non-normality, it would be helpful to include a brief explanation of why this test was chosen and how it addresses the research questions. Additionally, providing confidence intervals or effect sizes could enhance the interpretability of the results.
6. while it is noted that spinosad was the most effective for certain species, a more detailed comparison of the relative efficacy of each insecticide across different surfaces and exposure times would be valuable.
7. The results indicate that some insecticides lost efficacy over time, but there is no discussion on potential reasons for this decline. Factors such as surface degradation, insecticide degradation, or insect resistance could be explored.
8. The study could benefit from a discussion on how the findings can be applied in real-world scenarios, such as recommendations for specific insecticides and surfaces for different pest species.

Author Response

Manuscript Number: agriculture-3605200

Title: Insecticidal and residual effects of spinosad, alpha-cypermethrin, and pirimiphos-methyl on surfaces against Tribolium castaneum, Sitophilus granarius, and Lasioderma serricorne

Dear Editor,

Thank you for your letter regarding our paper entitled: “Insecticidal and residual effects of spinosad, alpha-cypermethrin, and pirimiphos-methyl on surfaces against Tribolium castaneum, Sitophilus granarius, and Lasioderma serricorne”. The comments of the reviewers are valuable and contribute greatly to the improvement of our work. In the following, we shall refer to these comments that, as you can see, have been addressed/incorporated.

I remain at your disposal should you need additional information.

Many thanks for your interest in our work.

Sincerely,

Paraskevi Agrafioti

Post-Doc Researcher

University of Thessaly

Laboratory of Entomology and Agricultural Zoology

The Manuscript entitled ‘Insecticidal and residual effects of spinosad, alpha-cypermethrin, and pirimiphos-methyl on surfaces against Tribolium castaneum, Sitophilus granarius, and Lasioderma serricorne’ presents a comprehensive study on the efficacy of three insecticides against stored product beetles on different surfaces over a six-month period. The study is relevant to the field of stored product protection and addresses practical concerns related to pest management in agricultural commodities.

1. The study addresses a significant issue in agricultural storage, namely the long-term efficacy of insecticides on different surfaces. This is highly relevant to the journal's scope, which focuses on agricultural practices and pest management.
2. The authors have tested three different insecticides (spinosad, alpha-cypermethrin, and pirimiphos-methyl) on four different surfaces (concrete, metal, plastic, and ceramic) against three key stored product beetles. This comprehensive approach provides valuable insights into the practical application of these insecticides.
3. Long-term Study: The study spans six months, which is a substantial duration for evaluating residual efficacy. This long-term perspective is particularly valuable for understanding the practical applicability of these insecticides in real-world scenarios.

REPLY: The authors would like to thank the reviewer for these comments and recommendations on improving the quality of the manuscript before resubmission. A revised version is submitted with the proposed corrections/additions addressed. A point-by-point reply to each comment/correction can be found below.

1. The results are presented in a highly detailed manner, with extensive numerical data in tables. However, the narrative summary of the results is somewhat lacking. The text could benefit from a more concise and clear summary of key findings for each species tested, especially highlighting the most significant trends and differences observed across insecticides and surfaces.

REPLY: Thank you for your comment. We appreciate your suggestion and agree that a clearer narrative summary of the results would enhance the readability and interpretation of our findings. In the revised version of the manuscript, we incorporated concise summaries of the key trends and differences observed for each species, focusing on the most notable effects of insecticides. Our aim was to improve clarity for the reader.

1. While the Kruskal-Wallis H-Test was used to analyze the data due to non-normality, it would be helpful to include a brief explanation of why this test was chosen and how it addresses the research questions. Additionally, providing confidence intervals or effect sizes could enhance the interpretability of the results.

REPLY: Thank you for your remark. We used Kruskal-Wallis H-test, since our data did not meet the assumptions of normality and homogeneity. This non-parametric method allowed us to assess whether there were statistically significant differences in mortality among insecticides tested without relying on those assumptions. Regarding the sub-second question, we appreciate your suggestion for the inclusion of confidence intervals or effect sizes to enhance the interpretability of our findings. While our initial focus was on identifying statistically significant differences among treatments.

1. while it is noted that spinosad was the most effective for certain species, a more detailed comparison of the relative efficacy of each insecticide across different surfaces and exposure times would be valuable.

REPLY: Thank you for your suggestion. We have revised the discussion part, please see lines 358-365.

1. The results indicate that some insecticides lost efficacy over time, but there is no discussion on potential reasons for this decline. Factors such as surface degradation, insecticide degradation, or insect resistance could be explored.

REPLY: We have included some sentences in the discussion part.

1. The study could benefit from a discussion on how the findings can be applied in real-world scenarios, such as recommendations for specific insecticides and surfaces for different pest species.

REPLY: We have revised the conclusion part.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have incorporated the changes in the revised manuscript wherever applicable