Review Reports - Textile Physical Barriers against the Chestnut Gall Wasp <i>Dryocosmus kuriphilus</i>

Round 1

Reviewer 1 Report

This is a good study about textile physical barriers against the chestnut gall wasp Dryocosmus kuriphilus. The results are clear at face value and the discussion appropriate. However, the results and discussion are less clear, and I have two primary concerns.

Introduction:

1. Line 34-35: “females (there are only females) oviposit inside leaves”. Generally speaking, the females of Dryocosmus kuriphilus oviposit inside buds. Please provide references to the statement “emales (there are only females) oviposit inside leaves”.

2. Line 37-38: Please provide references to the statement “The size of the galls is between 5 and 30 mm in diameter”.

3. In the introduction, please add a paragraph to mention the applications of “textile physical barriers” in the control of other insect pest.

Materials:

4. Line 61-62: Provide the latitude and longitude of sample site.

5. Line 76：Remove the underscore.

Resulsts and Discussion:

6. Line 233: Change the “the mean size of the abdomen width” to “that”.

7. In the results and discussion, please add a paragraph to compare this study and the applications of “textile physical barriers” in the control of other insect pest.

8. Please elaborate the shortcomings of this study and the research plan in the future.

Author Response

Dear reviewer,

I am very grateful for your comments. I response to your suggestions below:

Introduction:

1. Line 34-35: “females (there are only females) oviposit inside leaves”. Generally speaking, the females of Dryocosmus kuriphilus oviposit inside buds. Please provide references to the statement “emales (there are only females) oviposit inside leaves”.

You are right. We have not found references where it say that D. kuriphilus oviposits inside leaves. So we rewrite the sentence: "…oviposit inside buds".

2. Line 37-38: Please provide references to the statement “The size of the galls is between 5 and 30 mm in diameter”.

Well, it seems this is a complex issue. We found this value in a popular magazine but now that we have been searched more sources we prefer to remove this sentence because it is a sensitive matter. Thank you.

3. In the introduction, please add a paragraph to mention the applications of “textile physical barriers” in the control of other insect pest.

We have added the following paragraph:

"Protective textiles are a method of pest control whose use has spread rapidly in many regions of the world (12, 13, 14, 15, 16, 17) due to good results obtained with different pests (whiteflies, aphids, thrips, miner flies, etc.) although no previous study has carried out with D. kuriphilus. Non-woven polypropylene fabrics but mainly insect proof screens are textiles that prevent the access of insects to the crops. The structure of the woven screens is determined by two sets of threads (weft and warp) which interweave perpendicularly. The separation between threads and the thickness of the threads define the size of the holes. The design of the protective screens is a very complex matter and its optimal can be addressed from different points of view that very often are opposing solutions (exclusion vs ventilation and light transmission) [12, 18, 19]. Protective screens reduce populations of pests in the crop environment [20, 21, 22], decrease the incidence of insect-borne diseases [23, 24, 25, 26] and as a result the need for pesticide applications is reduced [23, 13, 27, 22, 28]. Also, some studies have shown promising results regarding the incorporation of insecticides into the threads making up the textile [29, 30] and recently, some works have been carried out on the addition of different types of silica (SiO2) nanoparticles as a non-toxic substance for insect control [31, 32]."

Materials:

4. Line 61-62: Provide the latitude and longitude of sample site.

Done.

5. Line 76：Remove the underscore.

Done.

Resulsts and Discussion:

6. Line 233: Change the “the mean size of the abdomen width” to “that”.

Done.

7. In the results and discussion, please add a paragraph to compare this study and the applications of “textile physical barriers” in the control of other insect pest.

We have added the following paragraph:

"This study adds to other works that have assessed the efficacy of protective screens against other pests. Except for the case of F. occidentalis [38], these studies reveal promising results against the main insect pests as well as this does. Therefore, the use of protective screens should be an additional and essential measure in Integrated Pest Management (IPM) [40, 41, 42]. Furthermore, the incorporation of additives into the threads [29, 43, 32] opens a new range of possibilities such as the use of less dense screens to prevent small insects without the drawback of the airflow resistance that current textiles offer."

8. Please elaborate the shortcomings of this study and the research plan in the future.

We have added the following paragraph:

"This work paves the way for future research, but some aspects can be improved: a greater number of wasps would be desirable to carry out the tests. On the other hand, although 3 m s-1 is not a very high air velocity, we have observed that as this variable increases the insects tend not to move and seek protection from the wind; for this reason, it would be advisable to introduce wind gusts in the tests carried out at higher air velocities. For example, a planned test at 5 m s-1 would be carried out at this maximum air velocity alternated with “short periods” of lower velocities. A new work could assess how to improve the simulation of the wind in the laboratory. And, of course, new works could optimize the design of a completely effective screen against D. kuriphilus."

Kind regards,

Antonio J. Álvarez

Reviewer 2 Report

The authors report on an important and interesting topic. However, I am confused after reading the manuscript and few of their previous papers. For example, in an earlier paper, they wrote, “A new design criterion is given for the theoretical prediction of the efficacy of the screens against insects harmful to crops. This criterion consists in the consideration of the generatrix d2 instead of the orthogonal width Lpx, and it explains why in some cases insects cross the screen holes when the hole width is lower than the size of their bodies”. Now it seems even d2 is not a good criterion since the manuscript suggests that screens with smaller d2 are worse than screens with larger d2.

The theory in this manuscript was already presented in their previous paper [14]. The experimental results are not in good correlation with the theory presented; therefore, I am not sure this manuscript warrants publication.

Following are specific comments:

1) Line 17: change “measurements” to dimensions

2) Line 126: The micrometer used (line 126) has a sensitivity of 10 micrometers. Your report of values with three decimal points results from the calculation, not measurement.

3) The method and calculations used to determine the surface area of the screen measured in 3D (lines 128 - 159) are unclear. This area should be well defined and shown on a schematic figure. Figs. 4 & 5 are not clear from this perspective.

4) Parameters a, c and d are not shown in Fig. 4. It is not clear from the figure what they are.

5) What is t in equations 3 & 4?

6) In Table 1, please add the standard deviation values to the mean values.

7) Revise the sentence on lines 241-243. The logic is not clear.

8) Lines 246-248: this is not correct. The diagonal dimension of the square should be smaller than the largest...

9) Textile thickness t is not given in Table 2; therefore, remove it from the table title.

10) Line 264: change thicknesses to diameters.

11) Explain how screen thickness is obtained. Show it in Fig. 4.

12) The differences between a 2d and 3d area are within 1.6 - 2.6%. These differences are very small and probably within the error of measurement of screen parameters.

13) Line 293: change experiences to experiments.

14) Table 4 does not show the shape factor values. Remove from the table title.

15) Table 4 how significant is the difference between the values of efficacies of the different screens? Show it with statistical analysis.

16) Lines 317-318: I am aware of experiments in which an increase in air velocity did not change efficacies since the insects tend to reach the screen and stay on it as if they were looking for protection against the wind.

17) Revise sentences on lines 324-329. The section is unclear.

I'm afraid I have to disagree with the conclusion on lines 339-342. The efficacy should be higher as the value of d2 is smaller. I agree with what the authors write on lines 314-315. I miss a statistical analysis showing how significant are the differences between values given in the tables.

Author Response

Dear Reviewer,

I am very grateful for your comments. I response to your suggestions below.

The Reviewer says:

...However, I am confused after reading the manuscript and few of their previous papers. For example, in an earlier paper, they wrote, “A new design criterion is given for the theoretical prediction of the efficacy of the screens against insects harmful to crops. This criterion consists in the consideration of the generatrix d2 instead of the orthogonal width Lpx, and it explains why in some cases insects cross the screen holes when the hole width is lower than the size of their bodies”. Now it seems even d2 is not a good criterion since the manuscript suggests that screens with smaller d2 are worse than screens with larger d2.

Authors answer:

"Generally screens with smaller d2 will be better than screens with larger d2. But if we only pay attention to this generatrix, we can be wrong." For example, screens number 1 and 2 have lower d2 values and they are less effective than the screen 3 because this last one have a lower 3D surface area due to its smaller hole length. We have also observed this behaviour with other pests. It is a complex problem and we have to look at several variables."

Because of this confusion, over years many manufacturers designed protective screens which gave bad results; that is if we had to choose between the screens selected in the paper without knowing what we now know we will select the screens number 1 or 2 and we would be wrong.

"Respectfully, we confirm that statement because the generatrix d2 is a more useful parameter than the hole width Lpx because it is measured in 3D and this is more real than the measures performed in 2D. But we must consider it along with other parameters".

Following are specific comments:

1) Line 17: change “measurements” to dimensions

Done.

2) Line 126: The micrometer used (line 126) has a sensitivity of 10 micrometers. Your report of values with three decimal points results from the calculation, not measurement.

Yes, the micrometer has a sensitivity of 10 micrometers. With this device we have measured the textiles thickness and the measures are in Table 3 in the row named tt (microns).

You are right. We have modified this paragraph to improve its understanding:

"However, all the above-mentioned parameters describe the screen from the point of view of its orthogonal projection. But from a microscopic point of view, the spatial arrangement of the threads that make up the textile determines that this 2D approach is not sufficient to explain the relationship between the screen and the insect. The real surface area that defines the three-dimensional space between the threads is a region of the hyperbolic paraboloid [35] as it can be seen in Figure 4. Using the variables that describe the protection screen from the 2D perspective (length Lpy and width Lpx of the hole and thickness of the warp thread Dhy) and considering the thickness of the textile tt measured using a micrometer (model 3050T, Baxlo) according to the standard ISO 5084:1996 [36], the surface area of the screen measured in 3D can be calculated using the method proposed by [35]:"

"Another parameter that becomes interesting when considering the 3D structure of the textile is the distance d2 that is a generatrix of the 3D hole surface and it is defined as the average spatial separation between the warp threads considering the middle of the hole from the point of view of its length (Figure 5). Theoretically the hole width Lpx measured in 2D prevents the entry of the insects if this dimension is smaller than the insect body size. However, the hole width Lpx does not change when the hole length Lpy increases (this happens when the distance between weft threads increases) or when the thickness of the screen varies and although the 2D surface area increases this is not relevant from an insect exclusion point of view. But when the hole length Lpy increases the spatial separation of the warp threads (z-axis) leaves a gap (3D) through which insects can cross the textile if this gap is big enough. A way to measure this gap and theoretically know if the insect can pass through the hole is by the 3D surface area A3D and the generatrix d2. This distance can be calculated using the method proposed by [35]:"

"Figure 4. Three-dimensional representation of a hole and 3D surface area; definition of the parameters a, c and d."

This method is a very complex mathematical problem. As the method is a part of the paper but not the main goal we refer the reader to the paper where this method is explained in depth.

4) Parameters a, c and d are not shown in Fig. 4. It is not clear from the figure what they are.

Please, look again the Figure 4. The parameters a, c and d are in this Figure but they are expressed in an implicit form.

5) What is t in equations 3 & 4?

We apologize because we have not included the value of t in the text. t is a geometric variable that takes these values:

when it comes to assessing the function F(t) , t is (-c + ad)/c
when it comes to assessing the function G(t), t is (ad)/(2c-ad)

Now we have included their values in the text. To avoid confusion we have named tt to the thickness of the textiles instead of t.

6) In Table 1, please add the standard deviation values to the mean values.

Done.

7) Revise the sentence on lines 241-243. The logic is not clear.

We have rewritten this sentence in this way:

"The thorax is the most limiting dimension for insects to cross the textile according to [37] despite this tagma is smaller than the abdomen. However, the thorax is more rigid and for this reason is taken as reference measurement so the screens selected should have the width hole lower than the dimensions of the wasp thorax."

8) Lines 246-248: this is not correct. The diagonal dimension of the square should be smaller than the largest…

Done.

9) Textile thickness t is not given in Table 2; therefore, remove it from the table title.

Done.

10) Line 264: change thicknesses to diameters.

Usually the cross-section of the threads is not a circle and for this reason we think it is better to use thicknesses instead of diameters.

11) Explain how screen thickness is obtained. Show it in Fig. 4.

We obtain the thickness of the screens with a micrometer specially designed for textiles following the procedure described in the standard ISO 5084:1996 "Textiles - Determination of thickness of textiles and textile products".

We have included in the text the reference to this standard.

12) The differences between a 2d and 3d area are within 1.6 - 2.6%. These differences are very small and probably within the error of measurement of screen parameters.

Yes, the differences between the two surface areas are small. It is obvious that the 3D surface area is always higher. But this difference along with the different arrangement of the surfaces (one of them is plane and the other one is three-dimensional) can make that the insect cross the textile or not.

13) Line 293: change experiences to experiments.

Done.

14) Table 4 does not show the shape factor values. Remove from the table title.

Done.

15) Table 4 how significant is the difference between the values of efficacies of the different screens? Show it with statistical analysis.

We have performed a statistical analysis now (results are shown in Table 4). No statistically significant differences in textile efficacy according to air velocity. It is normal because the screens number 1,2 and 3 has very high efficacy values. If we would have results for the screens number 4 and 5 at 1.5 and 3.0 m/s we would find probably statistically significant differences. We did not perform these tests because we had a small number on individuals and it was clear that these textiles were not efficient against D. kuriphilus.

We have also included this text:

"The effect of air velocity (to simulate the wind), which tends to reduce the efficacy of protective textiles, is not clearly seen in these results, probably for the reasons above mentioned or maybe because the hole size is small enough and the air velocity does not influence the efficacy of the textile. The statistical analysis performed (one-way ANOVA test [39]) do not show statistically significant differences in textile efficacy according to air velocity (Table 4)."

Yes, we agree. We have also observed this behaviour. But 3 m/s is not a high enough velocity for that to happen. However, we have introduced this paragraph at the end of Results and Discussion:

17) Revise sentences on lines 324-329. The section is unclear.

We have rewritten this sentence in the following way:

"This hole width would let pass the wasps through the screen if the hole length would be higher as it happens with screens number 1 and 2 because the insects cross the screen through one of the hole halves although this cannot be said considering only the 2D parameters and an explanation must be found in the 3D arrangement of the threads. Therefore, a hole width (2D) lower that the insect reference dimension (Tx=725) is not a guarantee than the screen will be effective. The same could be said about the generatrix d2. However, the screen number 3 has the lowest 3D surface area A3D so the combination of this variable along with the generatrix d2 becomes this screen as a completely effective protective barrier (at least at the conditions tested). These two parameters consider the hole width and length and the thickness of the screen. But insect’s ability is also an important factor in insect exclusion [37]."

Acconding to the comment: "I'm afraid I have to disagree with the conclusion on lines 339-342…" -> Respectfully but we think it is a right conclusion because at the range of values that manage the manufacturers (trade screens) this design criterion (prison effect) gave us at the tests weird results because we thought in 2D and therefore the insects should not cross the screen if the hole width is lower than the insect dimension until we realized that the threads are not arranged in a plane and that the insects cross the textile taking advantage of the higher surface that the threads left in the space. It is obvious that if the hole width continues to decrease there will be a limit at which insects will not be able to cross the screen regardless the hole length (but the textile will not be structurally stable and for this reason there is no such trade textiles).

Kind regards,

Antonio J. Álvarez

Round 2

Reviewer 1 Report

I agree to publish this work in agronomy。

Author Response

Dear Reviewer,

Thank you very much for appreciating our work.

Kind regards,

Antonio

Author Response File: Author Response.docx

Reviewer 2 Report

Line 21 - I suggest the authors are more cautious with their statements. Please change "is not a good" to "may not be a good".

Line 75 - "its optimal" is vague.

Line 156 - I insist that the authors change to "definition of the parameters a, c and d are given in [35]".

Line 374 - change higher to larger

line 377 - change that to than

line 378 - change than to that

Line 415 - range of air velocities or range of screen dimensions? please indicate in the manuscript.

Author Response

Dear Reviewer,

We very much appreciate your comments and suggestions. We response below:

Line 21 - I suggest the authors are more cautious with their statements. Please change "is not a good" to "may not be a good".

Done.

Line 75 - "its optimal" is vague.

We have changed "its optimal" by "the best approach". The sentence is a follows:

"The design of the protective screens is a very complex matter and the best approach can be addressed from different points of view that very often are opposing solutions (exclusion vs ventilation and light transmission)…"

Line 156 - I insist that the authors change to "definition of the parameters a, c and d are given in [35]".

Thank you for this suggestion and we apologize for not change it before. We have defined the parameters a, c and d in a explicit form which, as you suggest, is better because now it is easier to understand how to apply the method. Please, see the equations (2, 3 and 4).

We have also changed Figure 4.

Line 374 - change higher to larger

Done.

line 377 - change that to than

Done.

line 378 - change than to that

Done.

Line 415 - range of air velocities or range of screen dimensions? please indicate in the manuscript.

The sentence has been written as following: "Therefore, the design criterion (prison effect) based on restricting the hole width to prevent insect passage and increasing the length to avoid reductions in porosity does not give good results for this pest, at least in the range of geometric values of the screens tested"

Kind regards,

Antonio

Author Response File: Author Response.docx