Population Dynamics and Effect of Seed Treatment on Plutella xylostella Control in Romania

Round 1

Reviewer 1 Report

The manuscript presents the first report of diamondback moth DMB attack on oilseed rape (OSR) plants in autumn and high moths’ activity in OSR crop during November and December based on a three-year study concerning the effectiveness of the OSR seed treatment with the cyantraniliprole active ingredient in controlling the larva attack and a four-year monitoring of the DBM flight pattern using pheromone sticky traps. The findings would be useful for local management of the DBM.

 Major suggestions:

1. The current title reads like a review, and the abstract contains more method details than those of the results. I would suggest to use a more specific title, include more details of the results or connect the method and result of each part of pest attack or monitoring.

2. As this is not a review paper, the tables and figures would be used to facilitate the understanding on experimental logics and results. I found there are 7 tables and 2 figures in the section of Materials and Methods, and would suggest to re-consider the necessity of being placed in the main text, especially for tables 1 and 2 and figures 1 and 2.

3. There are several figures in the results featuring the larvae, adults and damage of the host plant. Are the phenotypes different from the previous reports? If not, they could also be provided as supplementary materials. Further, the figures of flight monitoring in different years could be combined into a plate of combinatorial figure. It is better to provide some more necessary figure legend.

 

Other issues:

L21, four years to four-year

L22, experience to experiment, and I also found in several places the same usage.

L38, DMB to DBM, and this mistake spreads throughout the manuscript.

L143, Experimental site, is it suitable to describe the details of experimental site here? I think some of them can be moved to the discussion.

L271, How does the OSR plants density calculate?

L456, For figures 5, 6, 8, 9 and 10, it makes no sense that the number is not an integer.

Author Response

Dear reviewer 1,

Thank you for your valuable comments, and suggestions. We took everything in consideration and according to that we corrected the text.

The manuscript presents the first report of diamondback moth DMB attack on oilseed rape (OSR) plants in autumn and high moths’ activity in OSR crop during November and December based on a three-year study concerning the effectiveness of the OSR seed treatment with the cyantraniliprole active ingredient in controlling the larva attack and a four-year monitoring of the DBM flight pattern using pheromone sticky traps. The findings would be useful for local management of the DBM.

 Major suggestions:

1. The current title reads like a review, and the abstract contains more method details than those of the results. I would suggest to use a more specific title, include more details of the results or connect the method and result of each part of pest attack or monitoring.

The original title of this paper was “Diamondback moth (Plutella xylostella) - a significant pest of oilseed rape in the southeast area of Romania”. The title was modified at the suggestion of the editors.

 

2. As this is not a review paper, the tables and figures would be used to facilitate the understanding on experimental logics and results. I found there are 7 tables and 2 figures in the section of Materials and Methods, and would suggest to re-consider the necessity of being placed in the main text, especially for tables 1 and 2 and figures 1 and 2.

Tables 1, 2 and Figures 1, 2 evidenced increasing of the temperatures as result of the global warming. Higher temperatures have a consequence in increasing DBM attacks at OSR plants, especially in the late autumn.

3. There are several figures in the results featuring the larvae, adults and damage of the host plant. Are the phenotypes different from the previous reports? If not, they could also be provided as supplementary materials.

The figures in the results with larvae, adults and damage to the host plants will be provided as supplementary materials.

Further, the figures of flight monitoring in different years could be combined into a plate of combinatorial figure. It is better to provide some more necessary figure legend.

I presented figures with DBM flight monitoring each year to evidence the pest fly peeks in late autumn or the first half of December (2022). I added more information in the figure legend. The figures are bigger. 

 Other issues:

L21, four years to four-year

I change to four-year

 

L22, experience to experiment, and I also found in several places the same usage.

I change to experiment.

 

L38, DMB to DBM, and this mistake spreads throughout the manuscript.

I changed to DBM, where it was mistakenly written DMB.

 

L143, Experimental site, is it suitable to describe the details of experimental site here? I think some of them can be moved to the discussion.

In "Experimental Site," I describe the details about the field site from NARDI Fundulea and some details concerning the field site climate and soil type. After a brief description of these aspects, I put into evidence the weather changes during this study period, such as the increasing temperatures in autumn. Higher temperatures increase DBM larval attacks on OSR plants in late autumn and modify the DMB moth's flight pattern.

 

L271, How does the OSR plants density calculate?

At each variant it has established 10 assessment points. At each assessment point, the OSR plants were counted on four randomly square meters using a metric frame.

 

L456, For figures 5, 6, 8, 9 and 10, it makes no sense that the number is not an integer.

The number of the figure is an integer. After the number, I put a point and then an explanation of the figure content

Reviewer 2 Report

Journal: Agronomy (ISSN 2073-4395)

Manuscript ID: agronomy-2320447

Title: Diamondback moth (Plutella xylostella) - a significant pest of oilseed rape in the southeast area of Romania

Authors: Emil Georgescu , Maria Toader * , Ioan Sebastian Brumă , Lidia Cană , Luxiţa Rîşnoveanu , Cristina Fătu , Roxana Zaharia

Section: Pest and Disease Management

Special Issue: Ecological Aspects as a Basis for Future Pest Integrated Management

 Abstract   Diamondback moth (Plutella xylostella Lepidoptera: Plutellidae) is a major pest of oilseed rape (OSR) worldwide. This paper presents a three-year study concerning the effectiveness of the OSR seed treatment with the cyantraniliprole active ingredient in controlling the diamondback moth (DBM) larva attack in autumn and a four years monitoring of the DBM flight pattern using pheromone sticky traps. Data from the field assessment reveal that higher attacks of the DBM larvae at OSR plants occurred in the last month of autumn. In 2019, on 20 November, in the untreated variant, the attack degree was 3.04%, while in the variant with treated seeds was 2.72%. A higher pest attack from this experience was observed on 11 November 2020, when the DBM larvae attack degree was 16.26 % in the untreated variant and 11.24% in the variant with treated seeds. In the autumn of 2021, the DBM attack at OSR plants was low. The DBM flight pattern monitoring results evidenced an unusually higher activity of this pest during November 2019, 2020, and 2022, the beginning of December 2020, 2021 and mid-December 2022. This is the first report from the Romanian literature concerning higher DMB attack at OSR plants in autumn and high moths’ activity in OSR crop during November and December.

 

Concerns:

There was no description in the Materials and Methods of a 2020 field test of B. thuringiensis that is referred to in Lines 581-583.

Suggestions:

Line 179-180: the average temperature for 2020 in Fig. 1 of 13.45 °C differs from text of 13.48°C

Line 192, 352, 452:  “filed” misspelled    …. field site

Line 209 and 436 : “draught”  misspelled  … drought

Line 218, 409:  change  “experience”  to  “experiment”

Line 288-289:  need to note the type of pheromone and a better source of these traps than ref. 96 which does not state company or the type of pheromone bait

96. Csalomon, Diamondback moth - Plutella maculipennis Curtis (= P. xylostella). Available online: http://www.csalomontraps.com/4listbylatinname/pdffajonkentik/plutellamaculipennisang08.pdf (accessed on 4.03.2023).

Line 347:   misspelled  “lower”    …equal to or lower than

Line 420:   change to  … OSR plant density at the variant with treated seeds was statistically higher than the control

Line 439: pests is not possessive, no ‘s      …sensitive to pest attacks

 Line 449, 453, 465, 466, 470, 471, 489, 490, 492, 496, 499, 513, 514, 515, 518, 522, 523, 526, 534, 535, 536, 554, 555, 559, 560, 561, 562:  

Suggest replacing  ”catche” or “catches number”  with …”moth numbers caught” 

Suggest replacing  “catches/trap” with  “moths/trap”

Line 457, 502, 611: what did you mean?  “possible explication”   or  “possible explanation”

Line 461, 485, 508, 545, 548:    Trap results of the DBM…

Line 467: reword  “…then the catches started to be recorded again…”  to  “…then traps began to catch moths again…

Line 495: …average number of moths caught

Line 498:  …but the moth numbers from traps

Line 499:  … a few moths in the traps

Line 501:  … lower rainfall amount

Line 512:  … DBM moths captured in delta traps

Line 568:  … high DBM moth activity

Line 647, 648, 650, 651, 692:  …DBM flight peek…

Line 666:   … fewer chemical options…

Line 669:  emphasize the need to improve field monitoring for DBM eggs and parasitoids to aid timing applications of insecticides during periods of potentially damaging levels of DBM hatch when parasitoids are not present to provide biological control of DBM

Comments for author File: Comments.pdf

Author Response

Dear reviewer 2

Thank you for your valuable comments, and suggestions. We took everything in consideration and according to that we corrected the text.

Journal: Agronomy (ISSN 2073-4395)

Manuscript ID: agronomy-2320447

Title: Diamondback moth (Plutella xylostella) - a significant pest of oilseed rape in the southeast area of Romania

Authors: Emil Georgescu, Maria Toader*, Ioan Sebastian Brumă, Lidia Cană, Luxiţa Rîşnoveanu, Cristina Fătu , Roxana Zaharia

Section: Pest and Disease Management

Special Issue: Ecological Aspects as a Basis for Future Pest Integrated Management

 Abstract   Diamondback moth (Plutella xylostella Lepidoptera: Plutellidae) is a major pest of oilseed rape (OSR) worldwide. This paper presents a three-year study concerning the effectiveness of the OSR seed treatment with the cyantraniliprole active ingredient in controlling the diamondback moth (DBM) larva attack in autumn and a four years monitoring of the DBM flight pattern using pheromone sticky traps. Data from the field assessment reveal that higher attacks of the DBM larvae at OSR plants occurred in the last month of autumn. In 2019, on 20 November, in the untreated variant, the attack degree was 3.04%, while in the variant with treated seeds was 2.72%. A higher pest attack from this experience was observed on 11 November 2020, when the DBM larvae attack degree was 16.26 % in the untreated variant and 11.24% in the variant with treated seeds. In the autumn of 2021, the DBM attack at OSR plants was low. The DBM flight pattern monitoring results evidenced an unusually higher activity of this pest during November 2019, 2020, and 2022, the beginning of December 2020, 2021 and mid-December 2022. This is the first report from the Romanian literature concerning higher DMB attack at OSR plants in autumn and high moths’ activity in OSR crop during November and December.

 

Concerns:

There was no description in the Materials and Methods of a 2020 field test of B. thuringiensis that is referred to in Lines 581-583.

The B. thuringiensis reference from the Discussion it isn’t in this paper experiment. It is a discussion concerning a study cited from the recent Romanian literature.

Suggestions:

Line 179-180: the average temperature for 2020 in Fig. 1 of 13.45 °C differs from text of 13.48°C

The correct average temperature is from the Figure 1. I correct in the text too.

Line 192, 352, 452:  “filed” misspelled    …. field site

I correct misspelled word.

 

Line 209 and 436 : “draught”  misspelled  … drought

I correct misspelled word.

Line 218, 409:  change  “experience”  to  “experiment”

I change to experiment.

Line 288-289:  need to note the type of pheromone and a better source of these traps than ref. 96 which does not state company or the type of pheromone bait

96. Csalomon, Diamondback moth - Plutella maculipennisCurtis (= P. xylostella). Available online: http://www.csalomontraps.com/4listbylatinname/pdffajonkentik/plutellamaculipennisang08.pdf (accessed on 4.03.2023).

In the official documentation, mentioned in reference 96, the type of pheromone is not specified. I sent the question to the manufacturer, but so far I have not received an answer. If we receive an answer in the next period, we will complete the information.

Line 347:   misspelled  “lower”    …equal to or lower than

I replace with “lower than”

Line 420:   change to  … OSR plant density at the variant with treated seeds was statistically higher than the control

I correct misspelled sentence.

Line 439: pests is not possessive, no ‘s      …sensitive to pest attacks

I correct misspelled word.

            Line 449, 453, 465, 466, 470, 471, 489, 490, 492, 496, 499, 513, 514, 515, 518, 522, 523, 526, 534, 535, 536, 554, 555, 559, 560, 561, 562:  

Suggest replacing  ”catche” or “catches number”  with …”moth numbers caught” 

I replace with ”moth numbers caught”

Suggest replacing  “catches/trap” with  “moths/trap”

I replace with ”moths/trap”

Line 457, 502, 611: what did you mean?  “possible explication”   or  “possible explanation”

I want to say “Possible explanation”. I correct misspelled word.

 

Line 461, 485, 508, 545, 548:    Trap results of the DBM…

I correct misspelled sentence.

Line 467: reword  “…then the catches started to be recorded again…”  to  “…then traps began to catch moths again…

I correct misspelled sentence.

Line 495: …average number of moths caught

I correct misspelled sentence.

Line 498:  …but the moth numbers from traps

I correct misspelled sentence.

Line 499:  … a few moths in the traps

I correct misspelled sentence.

Line 501:  … lower rainfall amount

I correct misspelled sentence.

Line 512:  … DBM moths captured in delta traps

I correct misspelled sentence.

Line 568:  … high DBM moth activity

I correct misspelled sentence.

Line 647, 648, 650, 651, 692:  …DBM flight peek…

I correct misspelled sentence.

Line 666:   … fewer chemical options…

I correct misspelled sentence.

Line 669:  emphasize the need to improve field monitoring for DBM eggs and parasitoids to aid timing applications of insecticides during periods of potentially damaging levels of DBM hatch when parasitoids are not present to provide biological control of DBM

I add a paragraph for evidenced need to improve field monitoring for better control of this pest and lower impact to parasitoids.

Reviewer 3 Report

In the manuscript titled "Population dynamics and effect of seed treatment on Plutella xylostella control in Romania" the authors describe about how P. xylostella was a minor pest of oilseed rape and has now become a major problem due to global warming. They also discuss about seed treatment of a particular insecticide 'cyantraniliprole' and the effectiveness of seed treatment of on on DBM population dynamics.

I have gone through the manuscript with great interest, although the work seem to have some merit, the authors seem to have not developed an exact structure to the manuscript. For example: the conclusion does not detail about the population dynamics or about the seed treatment.

I did not understand the rationale behind the connection between seed treatment and DBM attack. I know that DBM do not attack seeds, so what's the hypothesis behind this study?

The population dynamics study is poorly planned and does not contain anything of importance. It feels like the authors have simply dumped the data  with no hypothesis or plan to backup the manuscript.

Language also needs extensive editing and in some places is difficult to understand. For example: see this sentences "Increasing the temperatures due to global warming can have consequences in increasing the pest's attack on main crops. During our study, the average annual temperature in southeast Romania was higher than long-term averages. At the same time, it has observed a tendency to decrease rainfalls, especially in the autumn."

The manuscript needs a complete overhaul with a proper structure to be acceptable for publication.

Author Response

Dear reviewer 3,

Thank you for your valuable comments, and suggestions.

In the manuscript titled "Population dynamics and effect of seed treatment on Plutella xylostella control in Romania" the authors describe about how P. xylostella was a minor pest of oilseed rape and has now become a major problem due to global warming. They also discuss about seed treatment of a particular insecticide 'cyantraniliprole' and the effectiveness of seed treatment of on DBM population dynamics.

I have gone through the manuscript with great interest, although the work seems to have some merit, the authors seem to have not developed an exact structure to the manuscript. For example: the conclusion does not detail about the population dynamics or about the seed treatment.

In the case of high DBM attack in late autumn (November), seed treatment is less effective, although it has observed a decrease in the attack on the treated variant compared with the untreated (unchecked) variant.

Up until now, DBM was present in OSR crops in Romania but without significant economic damages. Rather, it was a significant pest of the cabbage crop. This study was the first report concerning a high DBM larva attack on an OSR crop in the autumn.

 

I did not understand the rationale behind the connection between seed treatment and DBM attack. I know that DBM do not attack seeds, so what's the hypothesis behind this study?

Seed treatment with systemic insecticides protects OSR plants in their early vegetation stages against sucking or chewing pests. After the ban on seed treatment with neonicotinoids active ingredients (imidacloprid, chlotianidin, and thiamethoxam), only cyantraniliprole active ingredient, an insecticide from the ryanoid class, remains available for OSR seed treatment against pests that attack this crop in early vegetation stages. Cyantraniliprole a.i. (commercial product Lumiposa) is a newer insecticide authorized for OSR seed treatment in Romania, from 2017. The effectiveness of cyantraniliprole a.i. in controlling the flea beetle (Phyllotreta spp., Psylliodes chrysocephala), cabbage leaf sawfly larva (Athalia rosae), and large white larva (Pieris brassicae) when OSR is in the early vegetation stage is well known. However, no studies were made in Romania concerning the effectiveness of the cyantraniliprole active ingredient in controlling the diamondback moth DBM (Plutella xylostella) larva attack in the autumn. In the last few years, farmers in Romania had problems because of this pest, but no research has been done concerning the effectiveness of seed treatment with cyantraniliprole in controlling the DBM.        

 

The population dynamics study is poorly planned and does not contain anything of importance. It feels like the authors have simply dumped the data with no hypothesis or plan to backup the manuscript.

Higher temperatures than normal favor this pest. Many studies reveal that in the last 20 years, increasing temperatures have resulted in higher pest attacks on agricultural crops. Also, some minor pest species can become major ones because of climate change.

The aim of this study is to determine if higher temperatures from Romania have consequences for DBM flight patterns in the OSR crop. It was the first study made in Romania concerning this topic.  It is the first report concerning the presence of DBM moths in the OSR crop in late autumn (November) or the first half of December. Till now, no such study was made concerning DBM in OSR crops in Romania.

Language also needs extensive editing and in some places is difficult to understand. For example: see this sentences "Increasing the temperatures due to global warming can have consequences in increasing the pest's attack on main crops. During our study, the average annual temperature in southeast Romania was higher than long-term averages. At the same time, it has observed a tendency to decrease rainfalls, especially in the autumn."

We edit the English language.

Round 2

Reviewer 3 Report

I don't see any efforts made by the authors on revising the manuscript. The language remains the same. Therefore, I must reject the manuscript.