Impact of artificial light intensity on nocturnal insect diversity in urban and rural areas of the Asir province, Saudi Arabia.

Continuous urban developments have resulted in increased demand for street furniture, one of which is street light columns. Artificial light at night (ALAN) pose significant impacts on insect diversity in urban and rural areas. The ALAN is a significant driver of decline in insect diversity. This study evaluated the impact of light intensity and sky quality at night on insect diversity in rural and urban areas of the Asir province, Saudi Arabia. Insect traps were installed in both areas during night. Light intensity of nearby road lamps was measured using light meter, while sky quality was measured using sky quality meter. Rural areas exhibited low light intensity (10.33 flux/f.candle) and good sky quality (18.80 magnitude/arcsec2). Urban areas exhibited intense light (89.33 flux/f.candle) and poor sky quality (15.49 magnitude/arcsec2). Higher insect diversity was recorded for rural areas where insects belonging to seven orders (i.e., Diptera, Lepidoptera, Hemiptera, Hymenoptera, Coleoptera, Neuroptera, and Dermaptera) were collected. However, insects of four orders (i.e., Diptera, Lepidoptera, Hemiptera, and Neuroptera) were found in urban areas indicating low diversity. Lepidopteran insects were frequently recorded from rural areas indicating they are attracted to artificial light. It is concluded that excessive ALAN and poor sky quality at night disrupt insect biodiversity. Therefore, ALAN and sky quality must be considered responsible for decline in insect biodiversity along with other known factors.

Introduction

Global insect diversity is declining and >40% of the world's insect species could go extinct over the next several decades if declining trends are not halted/reversed [1]. The most common drivers of these declines are intensive agriculture, excessive pesticide use, urbanization, climate change and habitat destruction [1, 2]. Dramatic loss of insect diversity in many parts of the world has attracted the attention of scientists to consider detrimental impacts on human health and livelihoods. Drastic decline of flying insects “Ecological Armageddon” was reported by Hallmann et al. [3]. Malaise traps were used by Hallmann et al. [3] to collect data from an agricultural landscape and >75% decline in insect biomass was recorded over 27 years. This study on decline in insect biodiversity gained significant attention in the scientific community. The substantial loss of insect populations can not only be explained by changes in habitat, climate or land use [3], but there are some other large-scale factors which could also be involved.

According to Grubisic et al. [2], artificial light could be an overlooked driver of insect declines. Urbanization has resulted with a new phenomenon associated with cities and towns called ‘light pollution” [4], which has significant impact on animals and insects throughout the world [5]. Increasing artificial light at night (ALAN) is the primary cause of this phenomenon. It is mainly connected to general population growth, industrial development and rising economic prosperity. Installation of lamps with higher luminous efficiency has also played a negative role in insect diversity declines.

The ALAN is known to have strong impacts on population dynamics of insects. Globally it has been increasing at an annual rate of 2%–6% over the last decades [6, 7], imposing an unprecedented alteration of natural light regimes and threatening biodiversity [8]. Despite its ubiquity, the importance of artificial light as an agent of global change is often overlooked when analyzing insect population declines. Insects perform many functions and provide essential support in agroecosystems. They provide ecosystem regulation services such as decomposition of organic material, nutrient and energy flow regulation, seed and pathogen dispersal, pollination, control of pests and conservation of biodiversity [9]. Therefore, decreasing number of insects may substantially affect maintenance of these functions and services, with consequences for food production and biodiversity health. Light is an important visual and non-visual cue for insects [10]. More than 60% of all invertebrates are nocturnal [8] and utilize nocturnal light for orientation, navigation, avoidance of predators, location of food and reproduction [11]. Many nocturnal and crepuscular insects use celestial light sources such as stars and the moon as visual cues for dispersal across landscapes [12].

The effect of sky quality and light intensity on nocturnal insects have never been studied in Saudi Arabia. The aim of this study was to examine the impact of ALAN on insect diversity in rural and urban areas. We emphasized the impact of artificial light on insects and compared the effect of sky quality at night and light intensity on nocturnal insects both in urban and rural areas of Saudi Arabia. We investigated the impact of ALAN on insect population declines in light-polluted areas and rural agricultural areas.

Materials and methods

The experiment was set up according to Manfrin et al. [13] with some modifications. Data relating to diversity of nocturnal flying insect in rural and urban sites were collected to evaluate the impact of light intensity and sky quality on insect diversity in rural and urban areas.

Study area

This field experiment was conducted in Asir province, Saudi Arabia. No specific permits were required to execute this study and the work did not involve any endangered species. Two different locations, i.e., Mohayil and Abha were selected for this study. We delimited locations according agricultural (Mohayil) and urban area (Abha). Mohayil is characterized by an agricultural landscape, whereas Abha is an urban area. An agricultural farm in Mohayil (18° 12ʹ 24.76ʺ N; 42° 32ʹ 17.51ʺ E) with no prior exposure to artificial light and another location in Abha city (18° 31ʹ 45.31ʺ N; 42° 2ʹ 42.95ʺ E) with light exposure were selected.

Environmental conditions

Data were collected during February and March, 2020. Light intensity was measured in lux through a light meter, Digitech, QM1587 (Reduction Revolution Pty Ltd, Parramatta, Australia) (Fig 1A). The light meter reads ambient light or direct light from an artificial source and calculates the correct shutter speed and aperture values required to capture an accurate exposure. The sky quality was measured in visual magnitudes per square arc second (magnitude/arcsec2) using sky quality meter (Unihedron, Ontario, Canada) (Fig 1B). Readings of the sky quality meter are inversely proportional to light; hence, higher digits indicate less light intensity. We compared sky quality measurements at different sites quantitatively.

Fig 1

Devices used in the experiment.

(A) light meter to measure the light intensity from nearby street lights, and (B) sky quality meter to determine the darkness of sky at night.

Insect collection and identification

Insects were collected from both sites using DynaTrap insect trap (Dynamic Solutions/MII Equipment Inc. Milwaukee, USA). It collects nocturnal flying insects including mosquitoes. Its ultraviolet light and whisper-quiet fan attracts and captures insects without zapping or buzzing. The trap does not use pesticides or chemicals or need an attractant or propane (Fig 2A). Traps were installed from evening to morning (19:00 to 7:00 local time) on every Thursday to Saturday. Sampling was carried out weekly during 1st February to 31st March 2020. The collected specimens were stored in papilon paper in the multipurpose plastic boxes and brought to laboratory for pinning and identification. Order level identification was primarily based on the description by Johnson and Triplehorn [14]. The collected specimens were kept in the Zoological Museum of the College for future reference (Fig 2B and 2C).

Fig 2

Experimental steps.

(A) DynaTrap insect trap for insect collection, (B) insect trap installed at a rural site and (C) counting and identification of captured insects.

Statistical analysis

Data were analyzed using the ‘pacman’ package Rinker et al. [15] in R (version 3.6.3; R Core Team, 2019). The analysis included boxplot structure, scatter plot and summary. Only night samples were analyzed for the comparisons of artificial light intensity and sky quality.

Results

Environmental conditions and measurements

Temperature, relative humidity, sky quality and light intensity were 26 to 27°C, 62% to 63%, 18.09 to 19.20 magnitudes/arcsec2 and 10 to 11 flux/f.candle, respectively in rural area. Similarly, a temperature between 18 and 19°C, 70% to 74% relative humidity, 15.18 to 16.10 magnitudes/arcsec2, and 88 to 90 flux/f.candle were recorded for urban area. The altitude of rural area was 530 m above sea level, while urban area is located at an elevation of 2215 m. Table 1 summarizes environmental data of both experimental sites. A significant difference (p ≤ 0.05) was observed in all environmental variables, i.e., light intensity, sky quality, altitude, relative humidity and temperatures between rural and urban area.

Table 1

Environmental data of rural and urban sites included in the study.

Location	Light Intensity (flux/f.candle)	Sky quality (msgs/arcsec2)	Altitude (m)	Relative Humidity (%)	Temperature (°C)
Mohayil (rural)	10.33 ± 0.58B	18.80 ± 0.61B	530 ± 0.0B	62.33 ± 0.58B	26.67 ± 0.58B
Abha (urban)	89.33 ± 1.15A	15.49 ± 0.53A	2215 ± 0.0A	72.33 ± 2.08A	18.67 ± 0.58A

Means followed by same letters within a column are statistically non-significant.

Light intensity at night was high (89.33 flux/f.candle) with low sky quality (15.49 msgs/arcsec2) in urban area. On the other side, rural area recorded limited manmade intervention (10.33 flux/f.candle) and better sky quality (18.80 msgs/arcsec2) (Fig 3).

Fig 3

Scatter plot showing the relationship between light intensity and sky quality at rural and urban areas.

Diversity of nocturnal flying insects

The insect traps installed at both areas collected insects belonging to seven different orders. Insects from rural site belonged to Diptera, Lepidoptera, Hemiptera, Hymenoptera, Coleoptera, Neuroptera, and Dermaptera orders. The insects collected from urban area belonged to four orders namely Diptera, Lepidoptera, Hemiptera and Neuroptera. The number of insects collected from Diptera, Lepidoptera, Hemiptera, Hymenoptera, Coleoptera, Neuroptera, and Dermaptera orders ranged between 0–43, 37–156, 0–55, 0–5, 11–66, 0–2 and 0–7, respectively in rural area. Similarly, 1–9, 2–9, 0–1 and 0–2 insects were collected for Diptera, Lepidoptera, Hemiptera and Neuroptera, respectively from urban areas.

The average number of insects collected from rural area in orders Diptera, Lepidoptera, Hemiptera, Hymenoptera, Coleoptera, Neuroptera and Dermaptera were 18.67, 89.67, 22.00, 1.67, 30.67, 1.00 and 3.00, respectively. In urban area average number of insects belonging to Diptera, Lepidoptera, Hemiptera and Neuroptera were 5.33, 5.00, 0.33 and 0.67, respectively (Fig 4). Lower population of Lepidopterans in urban area suggests that these insects were attracted to the uncountable number of the city white light LEDs. The peak of Lepidopteran insects’ attraction is attained when blue or white light emits shorter wavelengths around 400 nm [16]. It has been observed in Abha that a huge number of insects were attracted to newly-lit areas that have not been lit before. This attracts bats to feed on them. No attraction was observed to the high pressure sodium lamps within the city that are still installed in many roads, although white LEDs are now increasing in an alarming rate.

Fig 4

Box plot showing the population of insect orders in response to light intensity and sky quality.

(A) box plot for insect diversity in rural area and (B) box plot for insect diversity in urban area.

Discussion

Nocturnal insects are highly sensitive to light and their behavioral responses like dispersal, foraging, defense against predation, location of food, hosts, oviposition sites, resting sites and mate searching are governed by vision [17-25]. These behavioral responses of insects are very much related with light intensity (adaptation), circadian periodicity and photoperiodism [20, 24]. Nocturnal behavior of insects, their growth and physiology can be disrupted by the use of artificial light at night (ALAN) [23, 24]. However, the reason for this phototactic behavior, especially for ALAN in nocturnal insects remains unclear and may be driven by multiple factors [18, 20, 26]. The effects of environmental (e.g. light intensity, exposure time of light, polarization, weather and season) and physiological (e.g. sex, mating status, age and adaptation to the dark) factors as well as other anthropogenic activities (e.g. intensive agricultural practices), which leads are prominent examples that may affect insect’s population in rural and urban areas [27, 28]. As a consequence, long-term exposure of nocturnal insect communities to ALAN can lead to changes compared to communities that are less exposed to light [29, 30]. Most of the studies on the effect of light intensities have focused on birds, larger vertebrate animals and only a few studies have devoted on insect population affection light intensities. This is first study in the kingdom of Saudi Arabia investigating the impact of ALAN on nocturnal flying insects in urban and rural areas. The current study confirmed our hypothesis that sky quality and artificial light intensity influences composition and abundance of the insects. Phototactic behavior of insects is also affected by sky quality, light quality and external shape of light source [17, 18, 21, 31]. Species diversity and abundance of insects caught by light traps can change according to the light source, for example, LED bulb, compact fluorescent bulb or incandescent bulb [31]. In rural area sky was clear and light intensity from artificial sources was lower than urban areas. This phenomenon proved good for insect diversity and populations [17, 18, 21]. Indeed, natural areas with low-level of artificial light are valuable to maintain healthy ecosystem and balanced insect diversity. In rural area seven insect orders were observed compared to four insect orders in the urban area. Artificial illumination attracted large number of nocturnal flying insects. Light sources function as an ecological trap [32] for many insects. This occurs during swarming events, when very large numbers of population are attracted to artificial light sources [33]. If not killed immediately, insects are often unable to disperse and migrate elsewhere [32, 34]. Several studies have shown how artificial illumination disrupts dispersal patterns in arthropods, confounding natural sources of orientation (e.g., moonlight) and attracting positively phototactic insects [35, 36]. In this study, majority of insects collected in the light traps were of nocturnal nature suggesting that these might be sensitive; thus, more vulnerable to light intensity [37]. In urban areas, increased light intensity at night distracts significant number of insects. This could be a possible reason for the low diversity and the reduced number of insets. These results are in accordance with Horváth et al. [35], Meyer and Sullivan [36]. Moreover, the presence of artificial light may affect the distance that organisms and nocturnal creatures move away [34, 38]. The ALAN has substantial effects on insect fauna, including moths. Macgregor et al. [39] reported that moth abundance was reduced to half and flight activity was 70% greater at lit sites as compared to dark areas. They further reported a considerable reduction in pollen transport by moths at areas with artificial light. Their findings supported the disruptive impact of ALAN on moth activity, which is a one proposed mechanism driving moth declines, and suggest that street lighting may potentially affect pollination of nocturnal invertebrates. In our study, the lepidopteron insects were significantly higher in an agricultural farmland (that has not experienced lighting projects before) than urban area. These findings are in agreement with Macgregor et al. [39] who reported that street lights have disruptive impact on moth behavioral activities. Considering the overall scenario, our results demonstrate that the intensity of light in urban environment might be a potential threat to the nocturnal insects’ diversity.

Conclusions

Natural darkness at night is beneficial for insect species and entire wildlife. This may be understood by the high diversity of insects in rural areas. On the other hand, well-lit areas at night would negatively affect insect population, and this has been proved in this study. The right type of light and the intensity required for urban life are suggested to be considered carefully. Warm light that emits the wavelengths of yellow light may reduce some of the negative impacts and can reduce the number of insects attracted to irresistible artificial light.

13 Oct 2020

PONE-D-20-30451

Impact of artificial light intensity on nocturnal insects found in urban and rural areas of the Asir province, Saudi Arabia

PLOS ONE

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Reviewer #1: General comment:

The paper reports interesting and important findings on Impact of artificial light intensity on insect population. It is well executed paper, clearly written and sufficiently illustrated. The manuscript contains several minor inconsistencies which are commented in the following lists

Introduction:

Introduction is a good review of the knowledge on the subject. However, the presentation of the light impact behavior with different factors involved like declining insect population, impact of artificial light, local impact etc., need to be improved/ arranged paragraph wise. Also, the introductory part should be more elaborative with latest references in order to provide more comprehensive presentation of the problem.

Recent reports of insect population declines might be representing a global phenomenon in which the many stressors of the Anthropocene are pushing insects over the edge of population viability. This interesting aspect of artificial light use is defiantly stressing insects, we need to understand such patterns on insect decline and mechanisms. the authors must provide for these assertions/assumptions while writing introduction.

Methodology:

The methodology is succinct presented but correct. The figures are satisfactory, except Figure 1 which is poorly structured. The main purpose of these figures is to show the localization of rural and urban region of study area. Author must replace this with better one. I guess the work is very limited to the number of locations and even why this location is specifically chosen is not well expressed. Also the number of samples replicates have not been mentioned. The devices used to perform light intensity data and insect collection traps are standard one, I did not find the methods of insect identification used in this paper.

Results:

It is the best part of the manuscript. The results are focused and well presented on the insect population dynamics from both rural and urban areas.

Discussion:

The discussion consists in a good comparison of the insect populations from both urban and rural areas.

However, there is a fewer reference in the discussion section. The authors must provide more recent citations to justify the current study with previous one.

Reviewer #2: In the present manuscript the author did an effort to explore the “Impact of artificial light intensity on nocturnal insects found in urban and rural areas of the Asir province, Saudi Arabia”. The subject is really an interesting to read because the growing urbanization is adversely damaging the ecosystem of entire life in the world including insects. Insects are very beneficial for the life security as their contribution in crop pollination, honey production, and predator’s pf several other insect species are very important for the agriculture sector and food availability.

In the present study author, collected several insect species form the rural and urban areas in the Asir province of Saudi Arabia by using the latest techniques of insect collection. Present work highlights the importance of urban ecology study with reference to insect population and biodiversity in general.

Reviewer #3: The article is well written according to the title. However, the article has some grammatical issues. Therefore, it is my recommendation to revise the manuscript well.

I have highlighted some issues here;

Abstract

Line 19: Change“street light columns” by “street-light columns”

Line 23: Change“Light intensity” by “The light intensity”

Line 24: Change“light meter” by “a light meter”

Line 25: Change“darkness the sky” by “dark the sky”

Introduction

Line 36: Change“Decline in insect” by “A decline in insect”

Line 49: Change“new phenomenal” by “new phenomenon”

Line 60: Change“decreasing number” by “the decreasing number”

Line 60: Change“maintenance” by “the maintenance”

Line 67: Change“Arabia the effect” by “Arabia, the effect”

Line 68: Change“ALAN on insect” by “ALAN on the insect”

Materials and methods

Line 81: Change“An agricultural farm land” by “Agricultural farmland”

Line 104: Change“attracts and captures” by “attract and capture”

Line 116: Change“boxplot” by “the boxplot”

Results

Line 157: Change“high pressure sodium” by “high-pressure sodium”

Line 157: Change“installed in many” by “installed on many”

Line 158: Change“increasing in an alarming” by “increasing at an alarming”

Discussion

Line 173: Change“maintain healthy” by “maintain a healthy”

Line 173: Change“balanced diversity” by “a balanced diversity”

Line 177: Change“of population” by “of the population”

Line 184: Change“the possible reason” by “a possible reason”

Line 188: Change“fauna including” by “fauna, including”

Line 194: Change“in an agricultural farm land” by “in agricultural farmland”

Line 196: Change“have disruptive” by “have a disruptive

Conclusions

Line 200: Change“affect insect” by “affect the insect”

Line 202: Change“ Warm light” by “The warm light”

On the other hand, there is repetition of figure 5 and table 2, therefore use one thing.

Moreover, following reference could be cited;

Haider, I., Akhtar, M., Noman, A. and Qasim, M., 2020. Population Trends of Some Insect Pests of Rice Crop on Light Trap and its Relation to Abiotic Factors in Punjab Pakistan. Pakistan Journal of Zoology

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: Yes: Muhammad Qasim

Istitute of Insect Sciences

Zhejiang University

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Submitted filename: MS_LIGHT_INSECT_27_09_2020.docx

Click here for additional data file.

27 Oct 2020

Dear Dr. Shahid Farooq.

Academic Editor

PLOS ONE

Subject: SUBMISSION OF REVISED MANUSCRIPT (PONE-D-20-30451)

Thank you very much for your comments regarding our manuscript titled: “Impact of artificial light intensity on nocturnal insects found in urban and rural areas of the Asir province, Saudi Arabia”.

I have gone through all the changes suggested by the academic editor and reviewers. They pointed out very important points and provided very useful suggestions. I gave revised the manuscript accordingly. I have accepted all the changes suggested by the reviewers. Comments and responses of all the critique are presented in revised manuscript.

The detail of responses to the editor/ reviewer’s comments is provided below in a tabular form.

ACADEMIC EDITOR

1 The site selection needs clarity. One which basis these sites were selected? The delimitation of the site selection is provided in the text

2 Figure 1 must be replaced with a better one. Replaced

3 Introduction must be rearranged as suggested by the reviewers. Rearranged accordingly.

4 There should be more reference citations in the discussion section to support your claims. Done. Latest reference included

5 In acknowledgment figure 2 is about sky quality meter instead of insects. It is corrected and now this figure 2 replaced with figure 5.

6 Can the scale of Figure 5B be changed? Scale of Fig.5B Changed from 50 to 15.

Journal requirements

1 Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. Checked

2 We suggest you thoroughly copyedit your manuscript for language usage, spelling, and grammar. If you do not know anyone who can help you do this, you may wish to consider employing a professional scientific editing service The language of the manuscript has been edited by Dr. Philip Smith, Uludağ University, Turkey. The language editing certificate is attached as other file.

3 In your Methods section, please provide additional information regarding the permits you obtained for the work. Please ensure you have included the full name of the authority that approved the field site access and, if no permits were required, a brief statement explaining why? No specific permits were required to execute the study and the work did not involve any endangered species

4 We note that Figure 1 in your submission contains map images which may be copyrighted. The map was created by R statistical environment with open source shape files. Therefore, the figure is not copyrighted. The detailed explanation is provided in the legend of Figure 1.

REVIEWER-1

1 Introduction:

T Introduction is a good review of the knowledge on the subject. However , the presentation of the light impact behavior with different factors involved like declining insect population, impact of artificial light, local impact etc., need to be improved/ arranged paragraph wise. Also, the introductory part should be more elaborative with latest references in order to provide more comprehensive presentation of the problem. Recent reports of insect population declines might be representing a global phenomenon in which the many stressors of the Anthropocene are pushing insects over the edge of population viability. This interesting aspect of artificial light use is defiantly stressing insects, we need to understand such patterns on insect decline and mechanisms. the authors must provide for these assertions/assumptions while writing introduction. The introduction is thoroughly rearranging with the additions of latest reference as per the suggestion of referee.

2 Methodology:

The methodology is succinct presented but correct. The figures are satisfactory, except Figure 1 which is poorly structured. The main purpose of these figures is to show the localization of rural and urban region of study area. Author must replace this with better one. I guess the work is very limited to the number of locations and even why this location is specifically chosen is not well expressed. Also the number of samples replicates have not been mentioned. The devices used to perform light

intensity data and insect collection traps are standard one, I did not find the methods of insect identification used in this paper . Methodology is sufficient and the query of reviewer regarding the site delimitation is added in the text.

The number of samples replicates have already mentioned in text

Insect identification part is corrected in MS with appropriate references.

3 Results:

It is the best part of the manuscript. The results are focused and well presented on the insect population dynamics from both rural and urban areas. The section is further improved as suggested by reviewer-1

4 Discussion:

The discussion consists in a good comparison of the insect populations from both urban and rural areas. However, there is a fewer reference in the discussion section. The authors must provide more recent citations to justify the current study with previous one This section also rearranged as per the advice of reviewer and also the latest references have been provided in the justification of the present study

REVIEWER-2

1 In the present manuscript the author did an effort to explore the “Impact of artificial light intensity on nocturnal insects found in urban and rural areas of the Asir province, Saudi Arabia”. The subject is really an interesting to read because the growing urbanization is adversely damaging the ecosystem of entire life in the world including insects. Insects are very beneficial for the life security as their contribution in crop pollination, honey production, and predator’s pf several other insect species are very important for the agriculture sector and food availability. In the present study author, collected several insect species form the rural and urban areas in the Asir province of Saudi Arabia by using the latest techniques of insect collection. Present work highlights the importance of urban ecology study with reference to insect population and biodiversity in general. The presentation of the paper especially the introduction and discussion part is further improved.

REVIEWER-3

1 Abstract

Line 19: Change“street light columns” by “street-light columns”

Line 23: Change“Light intensity” by “The light intensity”

Line 24: Change“light meter” by “a light meter”

Line 25: Change“darkness the sky” by “dark the sky” Done

2 Introduction

Line 36: Change“Decline in insect” by “A decline in insect”

Line 49: Change“new phenomenal” by “new phenomenon”

Line 60: Change“decreasing number” by “the decreasing number”

Line 60: Change“maintenance” by “the maintenance”

Line 67: Change“Arabia the effect” by “Arabia, the effect”

Line 68: Change“ALAN on insect” by “ALAN on the insect”

Done

3 Materials and methods

Line 81: Change“An agricultural farm land” by “Agricultural farmland”

Line 104: Change“attracts and captures” by “attract and capture”

Line 116: Change“boxplot” by “the boxplot”

Done

4 Results

Line 157: Change“high pressure sodium” by “high-pressure sodium”

Line 157: Change“installed in many” by “installed on many”

Line 158: Change“increasing in an alarming” by “increasing at an alarming” Done

5 Discussion

Line 173: Change“maintain healthy” by “maintain a healthy”

Line 173: Change“balanced diversity” by “a balanced diversity”

Line 177: Change“of population” by “of the population”

Line 184: Change“the possible reason” by “a possible reason”

Line 188: Change“fauna including” by “fauna, including”

Line 194: Change“in an agricultural farm land” by “in agricultural farmland”

Line 196: Change“have disruptive” by “have a disruptive Done

6 Conclusions

Line 200: Change“affect insect” by “affect the insect”

Line 202: Change“ Warm light” by “The warm light” Done

7 On the other hand, there is repetition of figure 5 and table 2, therefore use one thing. Done

8 Moreover , following latest reference could be cited Cited

Yours truly,

19-October-2020 Khalid Ali Khan, Ph.D.

(Corresponding author)

Unit of Bee Research and Honey Production, Biology Department, Faculty of Science, King Khalid University Abha 61413, Saudi Arabia

29 Oct 2020

PONE-D-20-30451R1

Impact of artificial light intensity on nocturnal insect diversity in urban and rural areas of the Asir province, Saudi Arabia

PLOS ONE

Dear Dr. Khan,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

==============================

ACADEMIC EDITOR:

I have just gone through the files uploaded by the authors. Unfortunately, the track-changed manuscript and clean copy are different files, which made evaluation difficult. Therefore, I request authors to please upload same file for track-changed and clean copies.

==============================

Please submit your revised manuscript by Dec 13 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

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We look forward to receiving your revised manuscript.

Kind regards,

Shahid Farooq, Ph.D.

Academic Editor

PLOS ONE

[Note: HTML markup is below. Please do not edit.]

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29 Oct 2020

Dear Dr. Shahid Farooq.

Academic Editor

PLOS ONE

Subject: SUBMISSION OF REVISED MANUSCRIPT (PONE-D-20-30451)

Thank you very much for your comments regarding our manuscript titled: “Impact of artificial light intensity on nocturnal insects found in urban and rural areas of the Asir province, Saudi Arabia”.

I have gone through all the changes suggested by the academic editor and reviewers. They pointed out very important points and provided very useful suggestions. I gave revised the manuscript accordingly. I have accepted all the changes suggested by the reviewers. Comments and responses of all the critique are presented in revised manuscript.

The detail of responses to the editor/ reviewer’s comments is provided below in a tabular form.

ACADEMIC EDITOR

1 The site selection needs clarity. One which basis these sites were selected? The delimitation of the site selection is provided in the text

2 Figure 1 must be replaced with a better one. Replaced

3 Introduction must be rearranged as suggested by the reviewers. Rearranged accordingly.

4 There should be more reference citations in the discussion section to support your claims. Done. Latest reference included

5 In acknowledgment figure 2 is about sky quality meter instead of insects. It is corrected and now this figure 2 replaced with figure 5.

6 Can the scale of Figure 5B be changed? Scale of Fig.5B Changed from 50 to 15.

Journal requirements

1 Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. Checked

2 We suggest you thoroughly copyedit your manuscript for language usage, spelling, and grammar. If you do not know anyone who can help you do this, you may wish to consider employing a professional scientific editing service The language of the manuscript has been edited by Dr. Philip Smith, Uludağ University, Turkey. The language editing certificate is attached as other file.

3 In your Methods section, please provide additional information regarding the permits you obtained for the work. Please ensure you have included the full name of the authority that approved the field site access and, if no permits were required, a brief statement explaining why? No specific permits were required to execute the study and the work did not involve any endangered species

4 We note that Figure 1 in your submission contains map images which may be copyrighted. The map was created by R statistical environment with open source shape files. Therefore, the figure is not copyrighted. The detailed explanation is provided in the legend of Figure 1.

REVIEWER-1

1 Introduction:

T Introduction is a good review of the knowledge on the subject. However , the presentation of the light impact behavior with different factors involved like declining insect population, impact of artificial light, local impact etc., need to be improved/ arranged paragraph wise. Also, the introductory part should be more elaborative with latest references in order to provide more comprehensive presentation of the problem. Recent reports of insect population declines might be representing a global phenomenon in which the many stressors of the Anthropocene are pushing insects over the edge of population viability. This interesting aspect of artificial light use is defiantly stressing insects, we need to understand such patterns on insect decline and mechanisms. the authors must provide for these assertions/assumptions while writing introduction. The introduction is thoroughly rearranging with the additions of latest reference as per the suggestion of referee.

2 Methodology:

The methodology is succinct presented but correct. The figures are satisfactory, except Figure 1 which is poorly structured. The main purpose of these figures is to show the localization of rural and urban region of study area. Author must replace this with better one. I guess the work is very limited to the number of locations and even why this location is specifically chosen is not well expressed. Also the number of samples replicates have not been mentioned. The devices used to perform light

intensity data and insect collection traps are standard one, I did not find the methods of insect identification used in this paper . Methodology is sufficient and the query of reviewer regarding the site delimitation is added in the text.

The number of samples replicates have already mentioned in text

Insect identification part is corrected in MS with appropriate references.

3 Results:

It is the best part of the manuscript. The results are focused and well presented on the insect population dynamics from both rural and urban areas. The section is further improved as suggested by reviewer-1

4 Discussion:

The discussion consists in a good comparison of the insect populations from both urban and rural areas. However, there is a fewer reference in the discussion section. The authors must provide more recent citations to justify the current study with previous one This section also rearranged as per the advice of reviewer and also the latest references have been provided in the justification of the present study

REVIEWER-2

1 In the present manuscript the author did an effort to explore the “Impact of artificial light intensity on nocturnal insects found in urban and rural areas of the Asir province, Saudi Arabia”. The subject is really an interesting to read because the growing urbanization is adversely damaging the ecosystem of entire life in the world including insects. Insects are very beneficial for the life security as their contribution in crop pollination, honey production, and predator’s pf several other insect species are very important for the agriculture sector and food availability. In the present study author, collected several insect species form the rural and urban areas in the Asir province of Saudi Arabia by using the latest techniques of insect collection. Present work highlights the importance of urban ecology study with reference to insect population and biodiversity in general. The presentation of the paper especially the introduction and discussion part is further improved.

REVIEWER-3

1 Abstract

Line 19: Change“street light columns” by “street-light columns”

Line 23: Change“Light intensity” by “The light intensity”

Line 24: Change“light meter” by “a light meter”

Line 25: Change“darkness the sky” by “dark the sky” Done

2 Introduction

Line 36: Change“Decline in insect” by “A decline in insect”

Line 49: Change“new phenomenal” by “new phenomenon”

Line 60: Change“decreasing number” by “the decreasing number”

Line 60: Change“maintenance” by “the maintenance”

Line 67: Change“Arabia the effect” by “Arabia, the effect”

Line 68: Change“ALAN on insect” by “ALAN on the insect”

Done

3 Materials and methods

Line 81: Change“An agricultural farm land” by “Agricultural farmland”

Line 104: Change“attracts and captures” by “attract and capture”

Line 116: Change“boxplot” by “the boxplot”

Done

4 Results

Line 157: Change“high pressure sodium” by “high-pressure sodium”

Line 157: Change“installed in many” by “installed on many”

Line 158: Change“increasing in an alarming” by “increasing at an alarming” Done

5 Discussion

Line 173: Change“maintain healthy” by “maintain a healthy”

Line 173: Change“balanced diversity” by “a balanced diversity”

Line 177: Change“of population” by “of the population”

Line 184: Change“the possible reason” by “a possible reason”

Line 188: Change“fauna including” by “fauna, including”

Line 194: Change“in an agricultural farm land” by “in agricultural farmland”

Line 196: Change“have disruptive” by “have a disruptive Done

6 Conclusions

Line 200: Change“affect insect” by “affect the insect”

Line 202: Change“ Warm light” by “The warm light” Done

7 On the other hand, there is repetition of figure 5 and table 2, therefore use one thing. Done

8 Moreover , following latest reference could be cited Cited

Yours truly,

19-October-2020 Khalid Ali Khan, Ph.D.

(Corresponding author)

Unit of Bee Research and Honey Production, Biology Department, Faculty of Science, King Khalid University Abha 61413, Saudi Arabia

2 Nov 2020

Impact of artificial light intensity on nocturnal insect diversity in urban and rural areas of the Asir province, Saudi Arabia

PONE-D-20-30451R2

Dear Dr. Khan,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Shahid Farooq, Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

I have evaluated the revised manuscript. All the queries raised by the referees have been properly addressed. Therefore, the current version is accepted for publication.

Reviewers' comments:

19 Nov 2020

PONE-D-20-30451R2

Impact of artificial light intensity on nocturnal insect diversity in urban and rural areas of the Asir province, Saudi Arabia

Dear Dr. Khan:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

If we can help with anything else, please email us at plosone@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Shahid Farooq

Academic Editor

PLOS ONE