Preliminary Study on the Larval Development of Calliphora vicina (Diptera: Calliphoridae) on Different Types of Substrates Used as Reference in Forensic Entomology

Round 1

Reviewer 1 Report (Previous Reviewer 3)

Although the author have reformed the manuscript in some ways, there are still different aspects to be improved. Text editing needs to be improved; for instance, in lines 104-105 it could be read: "Caliphora (sic) vicina"  (wrong spelling and not in italics); or, in line 123, "A woman was placed...", instead of "A female..." and in line 215 (Calliphora sp.!!!). Then, authors should carefully revised the text.

On another level, the wording can still be improved. I.e., regarding the new paragraph (lines 103-112), it should be rewritten to make the lines 106-108 a continuous phrase after ":" 

The firt paragraph of Materials and Methods (lines 114-126) is hard to follow and the actual procedures remain obscure (i.e., "Females were captured using a previ-118 ously prepared experimental trap, consisting of a chicken meat support"... what kind of trap is it?, how was it designed?, is it described in the literature?...

Lines 143-144: I think Materials and Methods section has to describe the procedures followed and the devices used to perform the study. If something was wrong, such as breeding on pig liver, it should be discussed later (if considered convenient), not in this section.

What statistical processing was applied?

As it concerns Results and Discussions, lines 166-170 (and even 170-173) are better in Introduction. The last phrase (lines 170-173) is not supported by any new facts and does not introduce anything new to the species knowledge.

The statement of phrase in lines 176-177 is not supported by any reported data nor the study seems to be directed to determine such aspects. If the statement is due to the literature, it would be set out clearly, the same that if the observations made agree with the literature.

Data exposed in line 194 should be erased since they are in Tables 1 and 2.

Figure 4 seems to be composed of two identical graphics except that one of them shows the values (also repeated; they appear on the top of the histograms and as a Table!!).

Regarding the Conclusions, I think they must be of general typeand not to repeat the Results. So, they have to be reformulated in this sense. 

Some statements seems to be too categorical; i.e., that in lines 251-253. Perhaps, introducing a  "may be" or "presumably due to" (or similar), the original phrase would be better.

Then, I encourage the authors to revise critically the manuscript.

 

Author Response

Thanks you for your suggestions. 

Author Response File: Author Response.pdf

Reviewer 2 Report (Previous Reviewer 4)

Fig 4 needs to be corrected ("chart title" in the middle)...

The 1st paragraph of the conclusions needs to be rewritten since it is not clear what the authors intend to say.

Author Response

Thank you for your suggestions!

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report (Previous Reviewer 4)

Nothing to add to previous comments.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The submitted article deals with the collection of data on the development of a species of blowfly in two different types of substrate.

Studies of this type are important to allow the collection of reference data for experts in real cases of finding dead bodies.

If one species was used, why mention Calliphora sp?  It is recommended not to cite order and family names in italics.

 Questions regarding Materials & Methods:

- how many replicates were used?

- the 10 larvae were removed at what time intervals?

- if they were not returned to the substrate, did this affect competition for food in the sequence?

- if larvae were removed for measurement, how was survival calculated?

 

It is necessary to correct: in the first paragraph of the introduction, cite the minimum and maximum PMIs in sequence. - on lines 42-43: by Order Diptera, considering Calliphoridae, ... families; - on line 48: 13- 16 ^oC; - on lines 51-52: infestation and internal or external infections? It is necessary to rewrite. - on line 69; Richards (no italics); - on line 110: necrophagous diptera; - on line 136: protected from what? - lines 146-150: Materials and Methods? - on line 152: the citation of these references (36-38) was not understandable. In these studies, was there also an investigation of oviposition preference? - on lines 182-184: the text was not clear: Did the larvae hatch longer in the eye? Precise development time? - on line 190: their different approach or behaviour? - on line 198: parasitized by; The conclusions should be rewritten, preferably starting with the second paragraph. - on line 218: because its structure;  

 

 

Author Response

Dear Reviewer, 

thank you for your valuable comments. please find in the attach our answers 

Respectfully, 

Authors

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript is improved although there are still some areas that could do with further clarification or explanation.

Line 48 - you mention 13016 degree temperature for the species -  which species?

Line 69 - Richards should not be in italics

Line 75 -  tide?

Lines 84-87 you use are (are killed/are selected/are conducted...) should be were (past tense)

Line 95/96 deleted "gradually, according to the study of maggot and"

Line 146/147 -  The time frame of your data covers 264 hours (11 days), the 3 month timeframe of the overall project is not relevant

Line 198 - "parasites" should be "parasitized", in your results tables you say survival was 100% but parasitized pupae would not survive - this needs clarifying, what proportion of the samples you looked at were parasitized?

Lines 209-211 - unclear, initial development on the eye appears slower (72 hrs compared to 48) the larvae are larger (7mm compared to 3.29 mm) needs clarification and some explanation

Lines 211-212 - you suggest the higher nutritive food source has larvae of a smaller dimension, would you expect this? can you you give some explanation?

A bit more discussion to put your results in context with the real world application of forensic entomology e.g. effect of food substrate on both developmental time and length (e.g. your observation that larvae ion eye were larger but had a longer time period at L1 would be important when trying to apply life cycle information in PMI estimates).

Author Response

Dear Reviewer, 

thank you for your valuable comments. please find in the attach our answers 

Respectfully, 

Authors

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript deals with an aspect related to Forensic Entomology previously treated by different authors. Despite its potential interest by comparing fly development on two different pig organs, the study seems not to be well justified. The title of the manuscript reveals the preliminary nature of the study but, as pointed above, several studies on the same subject already exist. Then, the novelty of the current study is not clear or sufficiently explained.

Several aspects must be improved or corrected (see the pdf file with comments).

In general, the English spelling has to be reviewed, as well as other grammatical aspects. 

Despite the literature referred, some references (i.e Bernhardt et al., 2017, Int J Legal Med (2017) 131:847–853; Hadjer-Kounouz, 2017, Journal of Entomology and Zoology Studies 2017; 5(1): 683-691; Niederegger et al., 2013, Parasitol Res (2013) 112:2847–2853; Warren et al., 2018, PLoS ONE 13(2): e0192786,  https://doi.org/10.1371/journal.pone.0192786) are missing. They, among other concerning the same fly species or other fly species, are missing to improve mainly the results and discussion, as well as the conclusions).

A statistical comparison analysis is missing for the results. 

Deeper discussion and conclusion are needed.

 

 

Author Response

Dear Reviewer, 

thank you for your valuable comments. please find in the attach our answers 

Respectfully, 

Authors

Author Response File: Author Response.pdf

Reviewer 4 Report

The paper “Preliminary study on the larval development of Calliphora vicina (Diptera: Calliphoridae) on different types of substrate used as reference in forensic entomology” by Cristiana Manea (Amariei), Ion Sandu, Diana Bulgaru Iliescu, Norina Consuela Forna, Viorica Vasilache and Vasile Sîrbu, in its current form needs substantial revisions before it can be considered for publication.

It is hard to form a clear narrative or direction for the manuscript which I feel leads to it feeling a little aimless (see comments on Introduction and Discussion). I would focus on really tightening things up, defining a clear central objective (if not a hypothesis), and strongly directing the introduction and discussion round this. I think this will give the paper direction and make it easier to structure the paper and to see what is necessary and what is not.

Introduction: is too general. Authors should work from broad to narrow and therefore explain what they aimed to do in this study to address this research need.

Material & Methods: authors need to better organize the information. Calliphora vicina is mentioned in the title but in the manuscript, it is always indicated Calliphora sp... Was the work carried out with one species or with several species of Calliphoridae? Also, the present paper has insufficient data: ten specimens of each fly stage seem to be clearly insufficient.

Results & Discussion: looks very empirical. For example, the characterization of the organs (pig´s tongue and eye) is very basic. There is a mix of Material and Methods with Results and Discussion (e.g., L146-150 are Material & Methods)... The Discussion suffers from the same problem mentioned before: what is the aim of the discussion? What is it trying to say? To some extent, it is ultimately constrained because the study does not present any hypotheses (it is purely descriptive) and so the authors cannot address any questions in their discussion nor compare the results against other studies with a critical overview.

Finally, the written English is reasonable, but a thorough proofread by a native speaker would improve its legibility.

Author Response

Dear Reviewer, 

thank you for your valuable comments. please find in the attach our answers 

Respectfully, 

Authors

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Several suggested corrections were made. However, some details are still missing:

- on line 49, separate the temperature value from ^oC;

- on line 54: infestation by microorganisms?

- lines 176 and 177 should be on M & M.

- on Materials  and Methods:

- line 116: "analyzed gradually". Explain better how it was done. At what time intervals.

Were the larvae killed by immersion in boiling water from a replica and those that allowed calculation of survival from another replica?

 

- on line 132: reference study: which?

- on line 198: "significant" differences? Where are the statistical test values?

- on line 208: begins more difficult? Or starts later?

- on line 261: dipters?

Results and discussion starting with Also,....?

 

The new version of the conclusions is better than the previous one, but very extensive. Use more punctual and objective sentences.

 

 

 

 

Author Response

Thanks a lot for your comments and suggestions!

Author Response File: Author Response.docx

Reviewer 3 Report

The authors have made some changes in the manuscript, in some cases following the suggestions made but, in other cases, they have ignored them. Anyway, and despite such changes, the overall manuscript needs deep revision since there are some aspects not yet resolved beside the poorly organised general structure and development of the manuscript. One of the aspects to be revised deals with the Introduction, where there are paragraphs that seem more typical of Material and Methods or, even, of Discussion. In my opinion, Introduction does not explain sufficiently the reason or interest to carry out the study taking in mind that there are previous studies on the influence of food substrates on the development of the same species.

The Material and Methods section needs revision. What does “…individuals were analysed gradually…” mean? How, where and when were the adult females captured? Such females were immediately introduced in the Erlenmeyer glasses? How many females per glass? The breeding procedures are not clearly explained. The same regarding the procedure for samples revision. How often were the samples reviewed? This is not a trivial aspect depending on the larval stage and its own duration.

What was the aim and interest of taking photographs of the different stages? And where are the results of them?

If SPSS program was used for statistical study, why an ANOVA has not been applied to identify the statistical significance of means comparison?

Concerning Results and discussions section, the first phrase has no sense.

If the study was conducted for 11 days, was it possible to get adult specimens from the pupae? I think it was not. It is not known it the phrase in lines 181-182 is due to the literature [36-38] or to the results obtained.

The paragraph in lines 197-203 is not well statistically supported. As pointed above, are the differences found statistically significant? The graphic presented would be better in the form of a box and whisker plot. The literature mentioned in such paragraph is not cited. The sentence “… because it ensures a more nutritious content” seems to be a gratuitous claim.

It seems a bit strange that all the specimens moulted at the exact same time, as stated at tables 1 and 2.

Anyway, the statements are not well discussed with literature. This section would need a deep improvement, as well as Conclusions. For instance, lines 261—263 are not supported by literature. Lines 277-282 are difficult to be understood. Lines 283-286 do not conclude anything new since previous studies got similar conclusions. Other statements in Conclusions section simply repeat results.

Author Response

Thanks a lot for your comments and suggestions!

Author Response File: Author Response.pdf

Reviewer 4 Report

The paper “Preliminary study on the larval development of Calliphora vicina (Diptera: Calliphoridae) on different types of substrates used as reference in forensic entomology” by Cristiana Manea (Amariei), Ion Sandu, Diana Bulgaru Iliescu, Norina Consuela Forna, Viorica Vasilache and Vasile Sîrbu, still cannot be considered for publication since the authors did not make the necessary major changes suggested.

The Introduction is yet not well-structured. The authors added only two paragraphs of information at the end, that was taken ipsis verbis from the text they had in the Results & Discussion, without any elaboration/integration.

The authors continue to not discuss the results against other studies with a critical overview. I could give several examples, but mentioning just one, in Lines 199-203 they say: "Using these data and comparing them to the literature, we can conclude that pig tongue substratum is more favorable for the development of Calliphora vicina because it ensures a more nutritious content....", without quoting the papers nor the results of other works. More, the analysis shown in Figure 4 (the first one, as there are two Figure 4), does not show statistically significant differences to support the statement. Besides, the “second” Figure 4 is just a graphical repetition of the same data.

Then, the authors changed the previous Conclusion, which was clear and concise, for a text that is in fact discussion of the results (lines 261-292), but with very little scientific evidence supported by their results.

Author Response

Thanks a lot for your comments and suggestions!

Author Response File: Author Response.docx