Morphology and Distribution of Antennal Sensilla on Spodoptera frugiperda (Lepidoptera: Noctuidae) Larvae and Adults

Round 1

Reviewer 1 Report

It was a privilege to write this critique on the work. The fall armyworm (FAW) is an invasive pest that poses a serious threat to global food security. The purpose of this study is to investigate the variations in the antennal morphology and sensilla of the FAW. Because this was the first time that smell pores and a sensilla cavity had been seen in Lepidoptera larvae, they piqued a lot of people's interests. The authors need to do some work on the figures in general, despite the fact that the manuscript has very nice writing. I have included a list of my concerns on the PDF file itself for the authors to use as a reference. 

Comments for author File: Comments.pdf

Marked on the pdf file 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript written by the authors conducted morphological observations and comparison of antennal sensilla from third and fifth instar larvae and adults of Spodoptera frugiperda. While, I think there are many aspects of this manuscript that need to be improved. My general concerns and suggestions are listed as follow.

 Abstract

-The Abstract now is very descriptive, with too much morphological details but no key point. I suggest the authors to summarized the results and indicate the main conclusions of present study.

-I suggest the authors to clearly indicate which developmental stage (i.e., adults and third and fifth instar larvae) of Spodoptera frugiperda were examined in present study.

 Materials and methods

-Please clearly state which terminological system is used in present study.

 -Line 70, please provide the full name of “RH”.

  Results

-The location and arrangement of the Figures, Tables and the related captions and titles here are -very messy. For example, line 112-116, the caption of Figure 1 is presented above of Figure 1; and Figure 1 is inserted between Table 1 and its title. Similar issues are very common in this part. I am wondering whether the authors have read and checked the MS before submission.

 -Some types of sensilla existed both in larvae and adults (i.e., sensilla trichodea), and the authors described them twice, which is not necessary. I suggest the authors to combine the descriptions.

 -Table 1, confusing. The authors seem to use the data from fifth instar larvae as the experimental group without any explanation, which I feel very confused. Besides, there were some significant differences of sensilla length between third and fifth instar larvae but the authors did not provide any discussion or possible explanation of it. Similar situation existed in Table 3.

 -All the Figures here are in very low resolution, and many details of the morphological structures are obscure now. Please provide the images with at least 300 dpi.

 -Line 128, the authors used “smell pore” for description. Which literature did you refer to for this term? As far as I know, the term “pore” is more accurate to describe the minute pore structure on sensilla wall. Please carefully check the whole text and revise.

-Line 138, why there is a bullet symbol?

 -Line 167-170, wrong identification of sensilla type. The structures in Fig. 2A, 2F should be campaniform sensilla, which is a common type of insect sensilla.

 -Line 210, species names should be in italic.

 -Line 211-215, spelling error, “sensilla trichodae”--> “sensilla trichodea”.

 Discussion

Needs to be improved. The authors listed too much results about what previous studies did but just provided little discussion about what new knowledge is found by present study, which is not a real discussion, I think.

 The authors emphasized the observation of “smell pores” on sensilla of Spodoptera frugiperda, especially in the second paragraph, while, this pore structure is very common on insect sensilla wall.      

 The “sensilla cavity” mentioned here is the “campaniform sensilla”. Thus, the related discussion part should be improved.

Substantial changes and rephrasing of the text are needed. I would suggest the authors to make an improvement of the English.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Manuscript ID: diversity-2489779

Title: Morphology and distribution of antennal sensilla on Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae and adults

The research perspective of this manuscript is novel. The morphological characteristics of antennae and the type and distribution of antennae sensilla in the third and fifth instar larvae and adults of FAW were studied in this manuscript. The research is also very detailed, but there are still several points that need to be improved and clarified by the authors. First, the authors need to add more details to the material and method, such as the detailed operation of measuring the length and basal width of antennae and antennae sensilla. Second, the authors should not be too absolute in their statements, for example, the definition of antennal sensillum types is only based on references from other closely related species, so the statements in the results and discussions should not be too absolute. Finally, the authors need to closely relate the correspondence between the results and the discussion. Often, some discussions do not reflect the data in the results, and some discussions do not have the corresponding data to support them.

1. Whether the length and basal width of antennae and antennal sensilla are measured accurately. the authors state "We recorded images onto a computer and used SEM particle size statistics software to measure the length and basal width of each sensillum. We also measured the length and basal width of the entire antenna using an optical electron microscope" (L90-92) in Materials and methods, but it is clear that the way the material is placed and the angle at which the image is taken have a significant impact on the length measurement. Once the antenna is not extended, or the change in the shooting angle will affect the measurement length in the image. The authors should add details such as how to shoot and how to handle the materials in the materials and methods, rather than simply passing them by in one sentence.

2. How to define and classify the antennal sensilla of FAW is very vague in the materials and methods, and the authors use the sentence "The sensilla type and terminology used were based on available morphological characteristics and scientific reports published" (L94) to define it. I looked at these 4 references, none of which are about FAW. It seems an easy way to infer the antennal sensilla of FAW from the antennal sensilla of other species. But when it comes to subtle features such as antennal sensilla, the differences in detail are great from species to species, despite being very closely related (e.g. diamondback moth codling moth in the references),

3. In the results, the authors made a number of comparisons of the length and basal width of FAW antennae and antennae sensilla, including a comparison between 3rd and 5th instar larvae, and a comparison between females and males. But I've seen very little in the discussion about how these results correspond. In addition, whether it is of great academic interest to compare the length and width of different larval stages, the appendages of the younger larvae in most species are smaller than those of the older larvae.

4. The authors need to link the results with the discussion, the last paragraph of which focuses on the ability of antennal sensilla to sense temperature and humidity. However, there are no relevant studies to support the results, such as the size changes of antennae themselves or antennae sensilla under different temperature and humidity. The authors should not over-generalize their findings.

Minor editing of English language required

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Good to see the authors updated the main text according to many of the comments. However, I think the blurry image shown in results are not qualified for scientific publication. 

The resoulution of the images shown in the manusctipt are still very low, especially the Fig. 2F, Fig. 4D, Fig. 5H,  almost mosaic. Therefore, lots of morphological details described in the manuscript cannot be observed, which makes the scientific value of this paper questionable.

Author Response

Dear Editors:

Thank you for your letter and for the reviewer’s comments concerning our manuscript “Morphology and distribution of antennal sensilla on Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae and adults” (ID: 2489779). These comments are all valuable and very helpful for revising and improving our paper, as well as the importance guiding significance to our researches.

In response to your opinion, we resubmit the distinct figures as an attachment.

We greatly appreciate Editors/Reviewers' warm work earnestly, and hope the correction will meet with approval.

Best regards,

Zhang S.Z.

Reviewer 3 Report

The authors did a good job of addressing most of the issues I raised, and I had no more questions.

Author Response

Dear Editors:

Thank you for your letter and for the reviewer’s comments concerning our manuscript “Morphology and distribution of antennal sensilla on Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae and adults” (ID: 2489779). These comments are all valuable and very helpful for revising and improving our paper, as well as the importance guiding significance to our researches.

We greatly appreciate Editors/Reviewers' warm work earnestly.

Best regards,

Zhang S.Z.