Are the Interactions between Oaks and Pre-Dispersal Seed Predators Retained in Urban Environments? An Analysis of Two Quercus Species in Southern Mexico City
Round 1
Reviewer 1 Report
For Introduction
The following sources <(Nowack et al., 2002, 2006.....)> are not found in the References. Please check for drafting errors.
For Materials and Methods
At Seed sampling and processing (line 138-149)
a. Isn't it very clear how the samples were taken, how the trees were chosen and how many? What is the exact study area?
I suggest a detail of the method answering the above questions and highlight if the collection method is a well-established one (in which case please also mention the source) and if it is adapted to the subject of the paper and the given situation then it would be good to say this then simplifies the problem.
Pay attention to the area under analysis because it is so large (hundreds of hectares of what I understand) that it is impossible to evaluate and take samples in just 1 day a week as shown in the manuscript).
Given the size of the surface and the short sampling time (October-November 2015) it would be good to mention exactly the dates of the 8 sampling (for example, October 5/ sampling 1; ... and so on until sampling 8) .You can do this tabularly.
It is not a big effort, but it gives weight to the work and especially the credibility.
b. Who owns the formulas on line 144 and 162?
It is important to give these details and the source (for example Formula of after X, year y)
c. What did you mean by lines 142-143 with ... < registering its longitude (r1) and width (r2), longitude>?
I think it's about ...length and width ...; if so then please change <longitude> to lenght, or if the formula says so then leave it at that but be more explicit because longitude is associated with latitude at the macro level and longitude with width at the micro level.
d. Please put the meaning (:) on line 143, after the word <formula>.
e. For a better understanding of how the reader works, please mark on the map in Figure 1 (from line 117/Study site and study species) which are the sampling locations. I think it is easy to do and gives clarity to the overall picture of the methodology.
For Results and discussion
There is a wrong approach from the abstract and especially to the results of the systematic classification of the insect species targeted in the study. Sometimes you mention < Curculionids; Cydia >, sometimes <moth, Cydia>. The association is wrong anyway, from an entomological point of view.
I recommend a re-evaluation of the approach. Thus, either you use weevils and moth (without mentioning exactly the species) or you use Curculionid and Torttricid, or Cydia sp. and? - species of curculionids.
Example: In table 2 < (Curc., Cydia) = location × species> can be replaced with (name of weevil if you know?, Cydia) = location × species or (Weevil, Moths) = location × species>or (Curc., Tortr.) = location × species>.
It is a mess in terms of the correct classification of the arthropod species.
Why?
From an entomological point of view, because the target species are insects, I can explain:
- a species name is not associated with a family; if you do not know the species then associate the families (Curculionidae and Tortricidae are the families of the 2 target groups)
- does not mix chaotically as in the following example <weevil curculionids with Cydia> because it is wrong
I recommend a change of approach in presentation and description going by popular categories: weevil and moths and in the results to be mentioned in the tables and description which is the genus of weevil as you mentioned in moths (genus Cydia) sometimes species Cydia pomonella.
A change can be made throughout the manuscript, and this would change the value of the work; it is good that the work done is valued more (and from a scientific point of view).
For References
The following references are not found in the descriptive text, in any chapter.
<Nowak, D. J., & Crane, D. E. Carbon storage and sequestration by urban trees in the USA. Environmental Pollution 2002, 116(3), 381-442 389.
Nowak, D. J., Crane, D. E., & Stevens, J. C. Air pollution removal by urban trees and shrubs in the United States. Urban forestry & urban greening 2006, 4(3-4), 115-123>
Somewhere you mistyped the name of the first author (Nowack/ Nowak), either in the Introduction or in the References.
Author Response
Reviewer 1
For Introduction
The following sources <(Nowack et al., 2002, 2006.....)> are not found in the References. Please check for drafting errors.
--- The last name was not properly written in the introduction. It should have been Nowak. Nowak et al., 2002 and Nowak et al., 2006 were included in the references (lines 442-445 of the original submission).
For Materials and Methods
At Seed sampling and processing (line 138-149)
- Isn't it very clear how the samples were taken, how the trees were chosen and how many? What is the exact study area?
I suggest a detail of the method answering the above questions and highlight if the collection method is a well-established one (in which case please also mention the source) and if it is adapted to the subject of the paper and the given situation then it would be good to say this then simplifies the problem.
Pay attention to the area under analysis because it is so large (hundreds of hectares of what I understand) that it is impossible to evaluate and take samples in just 1 day a week as shown in the manuscript).
Given the size of the surface and the short sampling time (October-November 2015) it would be good to mention exactly the dates of the 8 sampling (for example, October 5/ sampling 1; ... and so on until sampling 8). You can do this tabularly.
It is not a big effort, but it gives weight to the work and especially the credibility.
--- We think there could have been some confusion with respect to the study area. It is not hundreds of hectares. We have changed the description of the study area to make it clear that we only sampled a portion of the protected area Center for Environmental Education Ecoguardas (132 ha) and a portion of the nearby Pichacho-Ajusco highway. We have also changed the legend of Figure 1 to make this point clearer. A larger area is depicted in the map of Figure 1 only to show Ecoguardas location in relation to the Ajusco Volcano and the Sierra.
We have also added some text to explain how the trees were chosen. This is not a previously established collection method. We designed it to have an equal number of trees/acorns in each of the two conditions we wanted to compare (i.e., the forest and the urban matrix).
The sampling period is short because the period during which there are mature acorns (starting when the first seeds fall) is short; it is a natural period. The 20 trees were previously located and marked, so it was quite feasible to visit all of them in only one day per week during the eight-week sampling period. In addition, as explained in the text, acorns of one species matured a little earlier than those of the other species, so we did not need to collect acorns from all 20 trees in each visit. However, we have included the sampling dates in the Methods section, as suggested.
We hope all of this is better explained in the new version of the Methods, to avoid any confusion.
- Who owns the formulas on line 144 and 162?
It is important to give these details and the source (for example Formula of after X, year y)
--- We have provided references for the formula of an ellipsoid (which is commonly used to calculate seed volume), and for the logistic regression, which is the model we used.
- What did you mean by lines 142-143 with ... < registering its longitude (r1) and width (r2), longitude>?
I think it's about ...length and width ...
--- You are right. It was our mistake, a bad translation from Spanish to English. We have changed longitude for length.
- Please put the meaning (:) on line 143, after the word <formula>.
--- Done.
- For a better understanding of how the reader works, please mark on the map in Figure 1 (from line 117/Study site and study species) which are the sampling locations. I think it is easy to do and gives clarity to the overall picture of the methodology.
--- We have rephrased the paragraphs in the subsection Study site to make it clear that we sampled only trees in the protected area Ecoguardas and in the nearby PA highway. We have also explained in the legend of Figure 1 that the area where we sampled is shown in orange. Given the scale of the map it is not possible to locate the 20 sampled trees on it.
For Results and discussion
There is a wrong approach from the abstract and especially to the results of the systematic classification of the insect species targeted in the study. Sometimes you mention < Curculionids; Cydia >, sometimes <moth, Cydia>. The association is wrong anyway, from an entomological point of view.
I recommend a re-evaluation of the approach. Thus, either you use weevils and moth (without mentioning exactly the species) or you use Curculionid and Torttricid, or Cydia sp. and? - species of curculionids.
Example: In table 2 < (Curc., Cydia) = location × species> can be replaced with (name of weevil if you know?, Cydia) = location × species or (Weevil, Moths) = location × species>or (Curc., Tortr.) = location × species>.
It is a mess in terms of the correct classification of the arthropod species.
Why?
From an entomological point of view, because the target species are insects, I can explain:
- a species name is not associated with a family; if you do not know the species then associate the families (Curculionidae and Tortricidae are the families of the 2 target groups)
- does not mix chaotically as in the following example <weevil curculionids with Cydia> because it is wrong
I recommend a change of approach in presentation and description going by popular categories: weevil and moths and in the results to be mentioned in the tables and description which is the genus of weevil as you mentioned in moths (genus Cydia) sometimes species Cydia pomonella.
A change can be made throughout the manuscript, and this would change the value of the work; it is good that the work done is valued more (and from a scientific point of view).
--- We explained in the original text that at present the identity of the species of Curculionidae feeding on the studied oak species is not known; however, most of them belong to the genus Curculio, although Conotrachellus has also been detected (lines 126-137 and 347-350 of the original submission). Thus, there could be more than one genus and the specific names are unknown; that’s why we chose the family name. Relating moths, we know they belong to the genus Cydia but we were unable to identify the species. We were aware that using a family name (curculionids for weevils) and a genus (Cydia for moths) meant mixing different categories. However, it did not seem entirely inappropriate because we knew the genus of the moths; by using instead the family name (Tortricidae), the reader loses information. We have considered your suggestion and used their popular terms (weevils, moths) in the results and discussion sections. In the Methods section the present status of their knowledge is explained, as before.
For References
The following references are not found in the descriptive text, in any chapter.
<Nowak, D. J., & Crane, D. E. Carbon storage and sequestration by urban trees in the USA. Environmental Pollution 2002, 116(3), 381-442 389.
Nowak, D. J., Crane, D. E., & Stevens, J. C. Air pollution removal by urban trees and shrubs in the United States. Urban forestry & urban greening 2006, 4(3-4), 115-123>
Somewhere you mistyped the name of the first author (Nowack/ Nowak), either in the Introduction or in the References.
--- You are right, the name was misspelled in the Introduction, and we have changed it for Nowak.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Line 18: What does authors mean by term “curculionid weevils”? Curculio genus? Rather strange term.
Line 128: Misspelled, should be Conotrachelus, single l.
Line 145-149: As an entomologist, I have serious doubts about method here. What if in same acorn both, moth and weevil larvae were present? Authors were still able to find the difference by the excrements only? From my knowledge it is possible that Cydia larvae would kill any other competing species. And by “curculionid” larvae authors mean on larvae from genus Curculio or other weevils too; where they able to distinguish them?
Line 217, Figure 2 A: So if I understand well, Forest = Ecoguardas? Judging by the presented map, this forest lays within urban area, only ~3kms from edge of urban area. Can it be really treated as natural forest and this compared with other urban, single trees??
Line 248-251: How do authors can make such assumptions if nothing about insects is known here – we have no idea how many species of moths and weevils are in fact developing in those oak trees. There might be various species, and from what we know about Curculio weevil some of them tend to be generalists, some more specialists.
Line 303-305: Not always, some research about Curculio indicate that they can fly over 10 kilometers. See: PÉLISSON, P. F., Bernstein, C., Francois, D., Menu, F., & Venner, S. (2013). Dispersal and dormancy strategies among insect species competing for a pulsed resource. Ecological Entomology, 38(5), 470-477.
Author Response
Line 18: What does authors mean by term “curculionid weevils”? Curculio genus? Rather strange term.
Line 128: Misspelled, should be Conotrachelus, single l.
--- We have changed it.
Line 145-149: As an entomologist, I have serious doubts about method here. What if in same acorn both, moth and weevil larvae were present? Authors were still able to find the difference by the excrements only? From my knowledge it is possible that Cydia larvae would kill any other competing species. And by “curculionid” larvae authors mean on larvae from genus Curculio or other weevils too; where they able to distinguish them?
--- We explained in the text (lines 189-190 of the original submission) that there were very few acorns having both types of larvae and they were excluded from the analysis. Yes, it is still possible to detect them by looking at the excrements, which are clearly different. By curculionid larvae we meant Curculio larvae, but as explained in the text (lines 127-128 and 347-350 of the original submission), species of Conotrachelus may also be present. Since it is not possible to distinguish different genus or species from larvae, we used the general term curculionid. However, in order to avoid confusion with terms relating to family (Curculionidae) and genus (Cydia) levels, we have replaced the names (Curculionid and Cydia) with the popular names weevils and moths, respectively, in the new version of the manuscript, as suggested by another reviewer.
Line 217, Figure 2 A: So if I understand well, Forest = Ecoguardas? Judging by the presented map, this forest lays within urban area, only ~3kms from edge of urban area. Can it be really treated as natural forest and this compared with other urban, single trees??
--- The forest in Ecoguardas is not a completely natural forest, as it has only 132 ha and is immersed within an urban matrix (although there are other protected areas nearby, not all of them depicted in the map). However, it keeps many natural characteristics and receives few visitors, which mostly remain in the facilities near the entrance. We have added a phrase in the Methods section to explain that we sampled trees in the central area of Ecoguardas to avoid edge effects. So, even if it has some influence from the surrounding urbanization, we believe it still is an (almost) natural forest, since no substantial human interventions other than sporadic visits have occurred since it was protected.
The urban trees sampled were most probably part of the same forested area before the PA highway was constructed during the 1970s. Although the natural forest in Ecoguardas has probably been impacted by urbanization, we believe ours is a valid comparison, as both are at the same altitude and similar environmental conditions. Finding larger natural oak forest patches to collect acorns in a relatively larger forest would imply sampling at higher altitudes, where Quercus castanea is rare and the comparison would be more complicated by differences in climate and forest species composition. We have added some comments on this on the second paragraph of the discussion.
Line 248-251: How do authors can make such assumptions if nothing about insects is known here – we have no idea how many species of moths and weevils are in fact developing in those oak trees. There might be various species, and from what we know about Curculio weevil some of them tend to be generalists, some more specialists.
--- You are right in that we do not know how many species of weevils or moths of the genus Cydia feed on our two oak species. This was acknowledged from the beginning in the manuscript. That is why we treated them as groups of species (weevils, moths). All we are saying in those lines is that, according to available information and our model, moths (as a group, but we think it is only one species), did not show a clear preference. However, a few lines below we state that sample size of acorns with moth larvae is low in relation to the total sample. Of course, these results can be refined when we get to know the identity and feeding preferences of individual species of Curculionidae or Cydia. This is recognized in the Discussion.
Line 303-305: Not always, some research about Curculio indicate that they can fly over 10 kilometers. See: PÉLISSON, P. F., Bernstein, C., Francois, D., Menu, F., & Venner, S. (2013). Dispersal and dormancy strategies among insect species competing for a pulsed resource. Ecological Entomology, 38(5), 470-477.
--- We were not aware of this paper and have included it in the discussion, recognizing that different species can have different traveling distances. We are thankful for this information. Although the authors report significant differences in dispersal ability of two Curculio species, average distances were not that large (600 m for C. elephas and 1200 m for C. glandium). A few females were able to travel up to 12 km, but the authors recognize that the experimental device overestimates the total distance and total time an insect usually travels by flight. The method is thus useful to detect trends and differences among species.
Author Response File: Author Response.pdf
Reviewer 3 Report
The paper report a nice research that will permit to expand our comprehension of ecological role plyed by isoletade trees on insect communities.
The paper is in general well written and presented, ùeven if some minor adjustments, as presented in the revised PDF, should be made. A part some correction requied in the references, I was not able to understand how the fina number of acorns examined in the filed (1220) was obtained comparing the indication provided in materials and Methods, that should give 8000.
Another serious concer is relative to the general methodology: you sampled acorns during just one year. As you correcly pointed out commenting one reference Mezquida et al (2021) the influence of different year may have a sensible impact on the communities. I think this should be taken in account and clearly commented in the text
Comments for author File: Comments.pdf
Author Response
The paper reports a nice research that will permit to expand our comprehension of ecological role played by isolated trees on insect communities.
The paper is in general well written and presented, even if some minor adjustments, as presented in the revised PDF, should be made. A part some correction required in the references, I was not able to understand how the final number of acorns examined in the field (1220) was obtained comparing the indication provided in materials and Methods, that should give 8000.
Another serious concern is relative to the general methodology: you sampled acorns during just one year. As you correctly pointed out commenting one reference Mezquida et al (2021) the influence of different year may have a sensible impact on the communities. I think this should be taken in account and clearly commented in the text.
--- We thank you for your careful revision of the manuscript which detected many small errors in the literature and improved our English writing.
There were 1200 acorns in the whole sample (around 50 acorns (or a few more) per tree x 20 trees). We hope it is clear now in the Methods section.
We have acknowledged in the discussion that abundance of the different species whose larvae feed on acorns can change in different years, and this may affect their interactions. Thus, longer term studies are needed to establish how much variation there is, as well as the existence of clear trends in insect feeding preferences.
Author Response File: 
Author Response.docx
Round 2
Reviewer 1 Report
Dear authors,
Thank you for taking into account my recommendations and also for the justifications given where appropriate.
I believe that the manuscript, in its current form, justifies its publication in Diversity.
Sincerely
Author Response
Thank you
Reviewer 2 Report
I am still not sure if authors were really able to determine larvae that easliy, without detailed identification. And what does authors mean by saying "However, in order to avoid confusion with terms relating to family (Curculionidae)"? Why using latin name of the familly would bring a confusion? authors were able to determine weevil genus by looking at larvae only?
Author Response
We have made our best effort to explain that feces allowed us to discern between weevils and moths, but we were not able to determine genus in neither of them. We changed terms to “weevils” and “moths”, as suggested by another reviewer, to avoid confusion.
