Evaluation of the Critical Parameters Involved in Decisions to Control Bactrocera oleae in Olive Orchards in the Southern Region of Lebanon

Round 1

Reviewer 1 Report

Introduction

 

- After Diptera replace ; with :

- The first sentence sounds segmented; perhaps more elaboration on the economic losses could help. The segmentation is present throughout the manuscript; a linguistic revision could help

- Adult females deposit ‘their eggs”; In several parts of the manuscript “its” is used instead of “their”

- A canopy diameter should be expressed as a single measurement; the way it is indicated in the manuscript is more indicative of an area

- why adding the ammonium bicarbonate? Was the beg sealed? Also, were other insects observed/collected even if they were not included in this research? 

- How was the sampling of the 6 fruit per zone conducted? Was it random? If yes, what were the procedures in place to make sure that it was random? Were they from different trees (but the same trees across all samplings?) Also, it is not clear how often the sampling was conducted; the manuscript only mentions two periods (Aug-Sept and then November)

- Figures descriptions are not visible

- It is not clear where the weather station for temperature data was located; was it on site? If not, how far from the field was it (I am not sure if it was 873m from it). Also, were data logger used in the field for the environmental parameter? 

- what is the third number indicated in the sex ratio? 

- It is not clear what the OFF attack is? What does it refer to and how was it measured? 

 

Overall I believe the findings of this paper are quite interesting; I would however suggest a general linguistic revision of the entire manuscript as well as a reorganization of certain paragraphs. I also suggest to clarify the material and methods based on the above edits to clarify the sampling schedule and procedures. Also, I would suggest to move the maps and the temperature to supplemental material, and to include instead some pictures of the colonized fruit and of the different stages (eggs – adults) of Bactrocera oleae

I believe an English revision is necessary

Author Response

Plesae check the document attached.

Author Response File: Author Response.pdf

Reviewer 2 Report

1. Usually there is a control in the experiment. What was used as a control in this work for comparative analysis of the rate of the fruit infestation (and some other indicators of fruit quality) on the territories under the traps' influence and without them.

2. The authors applied 2 Traps / ha. Such density should be justified by reference to the methodology.

3. Comparing the results obtained with the data of other experiments, is it possible to establish how effective the use of traps with such an attractant (ammonium bicarbonate), which attracts mainly males.

Author Response

Reply to the Reviewer 1:

1.Usually there is a control in the experiment. What was used as a control in this work for comparative analysis of the rate of the fruit infestation (and some other indicators of fruit quality) on the territories under the traps' influence and without them.

Reponse 1: The acceptable level of the olive fruit attack by the olive fruit fly is well known (2% for the dibble table and 10% for the oil olive destination). During our experiment we were searching after all the parameters (biotic and abiotic) added together to warn us for the intervention later on, and to determine where when and how to intervene.

2. The authors applied 2 Traps / ha. Such density should be justified by reference to the methodology.

Reponse 2:

Because “Sticky traps have been shown to be a rather poor method for controlling olive fly populations, but good for monitoring purposes because the numbers of trapped flies correlate with fruit infestation levels”. (23.  Ordano M., Izhar Engelhard, Polychronis rempoulakis, Nemny-Layy E., Blum M., Yasin S., Lensky I. M., Papadopoulos N. T.,  and Nestel D. Olive Fruit Fly (Bactrocera oleae) Population Dynamics in the Eastern Mediterranean: Influence of Exogenous Uncertainty on a Monophagous Frugivorous Insect. PLoS One. 2015; 10(5): e0127798. doi: 10.1371/journal.pone.0127798

And it used by 2 to 5 by Ha for monitoring and not for the control of Bactrocera oleae. (24. FAO/IAEA. 2018. Trapping guidelines for area-wide fruit fly programmes, Second edition, by Enkerlin, W.R. and Reyes- Flores, J. (eds). Rome, Italy. 65 pp. Licence: CC BY-NC-SA 3.0 IGO.

25. UC IPM Pest Management Guidelines: Olive UC ANR Publication 3452. Agriculture: Olive Pest Management Guidelines, 2014. Olive Fruit Fly, Bactrocera oleae)

N.B.:

a) Reference 23 is already written in the Bibliography under the number 32. We modified it to 23 in relation with the justification of the idea.

b) References 24 and 25 were added: in aim to have more references and to more justify our idea

3. Comparing the results obtained with the data of other experiments, is it possible to establish how effective the use of traps with such an attractant (ammonium bicarbonate), which attracts mainly males

Reponse 3:

References above (23, 24 and 25)

N.B. you will find these added references highlighted In the text.

 

Author Response File: Author Response.docx

Reviewer 3 Report

In this study，the researchers monitored the olive fruit fly, Bactrocera oleae (Rossi), with conventional yellow sticky traps, in 24.3 Hectares of non-irrigated Baladi olive cultivars, in Hassbaya region. The findings revealed that the first symptoms of the fruits were observed from 22 September,2022 when the BBCH was equal to 85%, with an average of adult captures lesser than 5 adults by trap by 7 days. However, the experiment is not well designed and performed.

1. A major concern is the authors only have one year of data, so it's a phenomenon rather than algorithm model, I didn't find any model throughout the manuscript.

2. Introduction: there is no present about the occurrence of the olive fruit fly, this information is very important for monitoring.

3. Material and Methods:

I don't understand figures 2(a) and figures 3(a), Are these TreeID just examples?

    Which data represented used ANNOVA tests? Which used Kruskall-Wallis Tests?

    Why 10 g ammonium bicarbonate was added to yellow sticky traps?

4. Results

     I couldn't understand the logic of the result part at all, Especially from 3.1 to 3.3: “3.1. Monitoring of the Adults”, “3.2. Adult Abundance”, “3.3. Spatial and Temporal Distribution of Bactrocera oleae Adults”, “3.4. Sex Ratio”, “3.5. BBCH and fruit Dimensions”, 3.6. Fruit Infestation.

     Discussion of the results should move to the discussion section.

5. Discussion: too simple, there is no connection with the objectives of the study in introduction section.

6. The full name is not displayed in the first time the abbreviation appears, for examples, BBCH and OFF, etc.

Author Response

Reviewer 2

In this study，the researchers monitored the olive fruit fly, Bactrocera oleae (Rossi), with conventional yellow sticky traps, in 24.3 Hectares of non-irrigated Baladi olive cultivars, in Hassbaya region. The findings revealed that the first symptoms of the fruits were observed from 22 September,2022 when the BBCH was equal to 85%, with an average of adult captures lesser than 5 adults by trap by 7 days. However, the experiment is not well designed and performed.

1.A major concern is the authors only have one year of data, so it's a phenomenon rather than algorithm model, I didn't find any model throughout the manuscript.

Reponse 1:

We tried to define the precise critical parameters (biotic and abiotic) to improve later on, the intervention against the Olive Fruit Fly, OFF, especially by bait spray design. We georeferenced all the trees, traps and the site. Obviously, the results were from one-year observations. We are now repeating the same design to confirm these results and to move on towards a semi-automated or automated system by using e-Traps. Thus, we found that the first symptoms would be related to Fruit load rate, to the BBCH value of the olives, and, obviously, the captures and the temperature values where the observations showed that the latest were inversely proportional to the temperature.  

That’s why,

We propose, now, to modify the paper title “Developing an algorithm model for Controlling Bactrocera oleae, in Olive Orchards in the South Region of Lebanon, by Using Conventional Traps”

 by “Evaluation of the critical parameters for taking decision to control Bactrocera oleae, in Olive Orchards in the South Region of Lebanon, by Using Conventional Traps”.

 

2.Introduction: there is no present about the occurrence of the olive fruit fly, this information is very important for monitoring.

Reponse 2:

If you mean that there is no present information about the olive fruit fly in Lebanon. Yes, the information related to the importance of the olive fruit fly in Lebanon is almost missed. In fact, we don’t have, unfortunately, any guidelines or published background about the importance of Bactrocera oleae, and its life cycle.

3. Material and Methods:

I don't understand figures 2(a) and figures 3(a), Are these TreeID just examples?

    Which data represented used ANNOVA tests? Which used Kruskall-Wallis Tests?

    Why 10 g ammonium bicarbonate was added to yellow sticky traps?

Reponse 3:

*Figure 2(a) and figure (b): yes, these are TreeID examples from OliveFlyNet applications interface which are showing details about information stored in the geodatabase system.

* The mean of the Dimensions and the BBCH of the fruits observed by date and by trap zones, were treated statistically, with the multiple mean comparison test, based on ANNOVA tests (Tukey Tests, p < 0.05; data represented a normal distribution).  On the other hand, the Rate of the Fruit Infestation observed observed by date and by trap zones, were treated statistically, with Kruskall-Wallis Tests (p < 0.05) because data wasn’t following a normal distribution.

N.B.: it is modified in the text

*10 g ammonium bicarbonate was added to the yellow sticky traps: it’s referred to what certain authors used and confirmed its efficiency in OFF monitoring (26). The reference 26 was mentioned in text under the number 30; it became now 26

4. Results

     I couldn't understand the logic of the result part at all, Especially from 3.1 to 3.3: “3.1. Monitoring of the Adults”, “3.2. Adult Abundance”, “3.3. Spatial and Temporal Distribution of Bactrocera oleae Adults”, “3.4. Sex Ratio”, “3.5. BBCH and fruit Dimensions”, 3.6. Fruit Infestation.

Discussion of the results should move to the discussion section.

Reponse 4:

*We designed, georeferenced all the site of around 24 ha of non-irrigated olive Baladi cultivar orchards; we installed yellow sticky traps, and got manually, all the observations related to the olive fruit fly, OFF, (its evolution in the site, its abundance and distribution in relation with the weather data). On the other hand, we followed the damages caused by the OFF (RFI) in relation with the fruit size and growth evolution (BBCH), in order to finalize all the critical parameters in relation with the OFF ecosystem, and to implement the next year, a semi-automated or an automated monitoring of Bactrocera oleae, in aim to precise when, where and how to intervene. We had to observe the abundance and the distribution of the adults; their relationship with the temperature and relative humidity values, the phenological growth of the fruit (BBCH) and the rate of the fruit load which was affecting the size of the fruit from one side and the rate of the olive fruit fly attack from the other side.

Thus, we found that the captures were inversely proportional to the temperature. On the other hand, the findings revealed that the first symptoms of the fruits were observed from 22 September, when the BBCH was equal to 85%, with an average of adult captures lesser than 5 adults by trap by 7 days.

  *Discussion of the results: Since the template of the “Applied Sciences” allow us to discuss the results in the “Results paragraph”, we compared some of our findings to others which were observed in other countries. That’s why we estimate that writing our results in this way keep the text more comprehensive.

5. Discussion: too simple, there is no connection with the objectives of the study in introduction section.

Reponse 5:

 We explained our objectives in the end of the Introduction paragraph “Thus, the objectives of this study were to evaluate the critical parameters for taking decision to know when, where and how to spray, especially the number of the adults captured by yellow sticky traps added with the attractant Ammonium bicarbonate, the observations of the infested fruits coupled with climatic data (temperature, relative humidity, etc…), the phenological characteristics of the tree, especially the fruit load rate”

And in the “Discussion paragraph”, and obviously, after discussing our results in the Results paragraph and in the Discussion paragraph, we mentioned “These results highlighted the importance of the fruit load rate in relation to the OFF attack. Thus, the infested fruits were correlated as much with the fruit load rate or the size of the fruit as with the number of adults captures. Then our observations allow us to set an algorithm model for bait spraying intervention, when we have the first symptoms, taking into consideration the threshold of the BBCH equal at least 85%, that of the fruit load lesser than 25%, with an average of adult captures lesser than 5 adults by trap by 7 days”

Therefore, you mentioned that our Discussion is too simple, and it is not very relevant:  your recommendation, here, is not very clear for us, since you didn’t precise what you were expecting more, or which part of our discussion was too simple.

6. The full name is not displayed in the first time the abbreviation appears, for examples, BBCH and OFF, etc.

Reponse 6:

BBCH derives from Biologische Bundesanstalt, Bundessortenamt and CHemical industry (27, 28, 29).

OFF, The olive fruit fly

etc.: I would prefer if you were more precise in this word.

 

N.B.: all the modifications were added to the manuscript text

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The revised paper is qualified for publication

Author Response

- After Diptera replace ; with :

Response: added in the manuscript 

- The first sentence sounds segmented; perhaps more elaboration on the economic losses could help. The segmentation is present throughout the manuscript; a linguistic revision could help 

Response:

The Olive tree is considered one of the most important cultivated crops in Lebanon. It represents about 43% of the cultivated area with fruit trees [1]. This crop is threatened by several pests especially, the olive fruit fly (OFF), Bactrocera oleae Rossi (1790) (Diptera: Tephritidae). This pest is widely distributed in the Mediterranean basin, Middle-East and North Africa and poses a severe economic threat for commercial olive growers, causing economic losses [2, 3, 4, 1]. In fact, in areas where olive fruit fly is well established like in the Mediterranean region, it has been responsible for about 30% crop losses, especially in countries such as Greece, Italy, Spain and Tunisia where large commercial production occurs. If not treated it is capable of destroying 100% of table cultivars and up to 80% of oil value [2, 3, 4]. In Lebanon, the damage losses are not yet reported.

N.B.: This paragraph is added to the manuscript

 

- Adult females deposit ‘their eggs”; In several parts of the manuscript “its” is used instead of “their” 

Response:

The adult females deposit their eggs (50-400 eggs in her lifetime) under the skin of the fruit [5].

 

- A canopy diameter should be expressed as a single measurement; the way it is indicated in the manuscript is more indicative of an area 

Response:

Yes, it was mentioned as indicative of our area. We are talking of about 24.3 Ha of Olive groves.  In this paragraph we tried to demonstrate the huge variation in the whole land owned by 26 farmers, despite the application of the same agricultural practices; this would be related, not only to the heterogeneous land, but also to the variation in the age of the trees, tree-distances, and thus in the canopy size: 

“The same agricultural practices were registered despite the variation in tree age, 20-70 years old, and in tree distances, 5 to 8 m giving a density of 250 to 350 trees by ha, or 5353 Trees as total number in 24.3 ha. Tree height is ranging between 3 and 7 m, with canopy diameter between 3×3 m and 7×7.5 m.”

 

 

- why adding the ammonium bicarbonate? Was the beg sealed? Also, were other insects observed/collected even if they were not included in this research?  

Response:

The ammonium salts are very attractant to Tephritidae Pests, and in our case, Bactrocera oleae: 10 g ammonium bicarbonate was added to the yellow sticky traps (figure 4): it’s referred to what certain authors used and confirmed its efficiency in OFF monitoring (26).  

N.B.: This reference is added to the manuscript

 

Why the use of the yellow sticky traps: Because “Sticky traps have been shown to be a rather poor method for controlling olive fly populations, but good for monitoring purposes because the numbers of trapped flies correlate with fruit infestation levels”. (23), and it used by 2 to 5 by Ha for monitoring and not for the control of Bactrocera oleae (24, 25).

N.B.: This reference is added to the manuscript

For the question related to the other observed insects captured by the traps: Our main target in this manuscript, was the OFF Captures. Obviously, we captured many other pests and beneficial insects; Thus, we didn’t follow, on purpose, the other captured pests. and we preserved our right to publish the results concerning the beneficial insects for another paper.

 

 

 

- How was the sampling of the 6 fruit per zone conducted? Was it random? If yes, what were the procedures in place to make sure that it was random? Were they from different trees (but the same trees across all samplings?) Also, it is not clear how often the sampling was conducted; the manuscript only mentions two periods (Aug-Sept and then November) 

Response:

The sampling was it random? In paragraph 2.5.2. We mentioned that, we collected fruits, randomly, from 29 July till the end of the experiment to follow the BBCH evolution and to measure the fruit size and the rate of the fruit infestation, RFI…. “We collected, randomly, and examine 6 fruits per zone Trap till September 22 (total of 250 fruits); after this date, we had collected 12 fruits per zone Trap (total of 588 fruits) to have more representative samplings knowing that the rate of infestation would be increased”.

 

Yes, we collected the fruits randomly by zone trap; which is mean: from each zone trap (we had 49 zone traps). Thus, we collected them by crossing the field following the letter W, and choosing the fruits.

N.B.: I added this sentence to the manuscript.

How often the sampling was conducted: at weekly basis and randomly

N.B.: I added this sentence to the manuscript.

the manuscript only mentions two periods (Aug-Sept and then November):  N.B.: We added a sentence in paragraph 2.5.2. to clarify the sampling date: “The BBCH and the dimensions (W×L, Size) of the olive fruits observed and registered from 29 July till 10 November: examination of 6 fruits (total of 250 fruits) per zone Trap till 15 September, then 12 fruits (total of 588 fruits) per zone trap (588 fruits as total) (figure 6-a)”.

 

On the other hand, the figures 16, 17 and the table 12 and the text behind, described very well, the BBCH and the fruit size evolution, weekly, from 29 July till 7 Oct where the fruits reached their stability in the BBCH status and the size. The figure 18 explained very well the evolution of the infestation rate, by fruit load rate registered, from their appearance (22 Sept) till the end of the experiment (10 November), at weekly basis.

 

 

- Figures descriptions are not visible (this note is not really clear; but the manuscript clarified each figure concerning each data of our observations)

 

- It is not clear where the weather station for temperature data was located; was it on site? If not, how far from the field was it (I am not sure if it was 873m from it). Also, were data logger used in the field for the environmental parameter? 

Response: The weather station is far 1 km from the site and at 873m. of altitude. This weather station belongs to LARI Station registered all the climatic data at 15min basis, 24/7.

N.B.: I added “far 1 km from the site” and “24/7” to the manuscript.

 

- what is the third number indicated in the sex ratio?  

Response: We didn’t really understand this remark. In fact, we tried to demonstrate the sex ratio evolution in time, at weekly basis. For ex on 25 August we observed 0.47 F over 1 male (0.47: 1) etc…

 

- It is not clear what the OFF attack is? What does it refer to and how was it measured? 

Response: in paragraph 2.5.3. We added: We collected, at weekly basis and randomly (we crossed the field following the letter W to collect the fruits), and examine 6 fruits per zone Trap (we had 49 zone Traps).

On the other hand, we added to “Each fruit was examined at LARI Laboratory …..or 4) empty hole (figure 6-b, 6-c, 6-d, and 6-e, respectively)”.

N.B.: the last sentence is added to the paragraph and the four photos related to the symptoms

 

Overall I believe the findings of this paper are quite interesting; I would however suggest a general linguistic revision of the entire manuscript as well as a reorganization of certain paragraphs. I also suggest to clarify the material and methods based on the above edits to clarify the sampling schedule and procedures. Also, I would suggest to move the maps and the temperature to supplemental material, and to include instead some pictures of the colonized fruit and of the different stages (eggs – adults) of Bactrocera oleae 

Response: Clarified and added above

 

 

Comments on the Quality of English Language: 

I believe an English revision is necessary 

Response: We Made our best for the quality of English language; Remark: The other two reviewers didn’t mentione this note.