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Impact of light pollution on moth morphologyA 137-year
study in Germany
Silvia Keinath
a,b,
*, Franz H€
olker
c,d
, Johannes M€
uller
a,b
, Mark-Oliver R€
odel
a,b
a
Museum f€
ur Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, Berlin 10115,
Germany
b
Berlin-Brandenburg Institute of Advanced Biodiversity ResearchBBIB, K€
onigin-Luise-Str. 2-4, Berlin 14195,
Germany
c
Leibniz-Institute of Freshwater Ecology and Inland Fisheries, M€
uggelseedamm 310, Berlin 12587, Germany
d
Institute of Biology, Freie Universit€
at Berlin, Berlin 14195, Germany
Received 12 June 2020; accepted 27 May 2021
Available online 31 May 2021
Abstract
Increasing artificial illumination during night has multifaceted effects on species. Moths are shown to be distracted and
attracted by artificial light sources, leading to increased mortality through predation or exhaustion. Increased mortality can be
expected to increase selection pressure on morphology, particularly those being functional in light detection and flight ability.
We were thus interested if intraspecific traits differ between areas and times with differing light pollution values. We chose the
moth Agrotis exclamationis, a common species in the Berlin-Brandenburg region, Germany, a region that offers very different
levels of light pollution across space and time. We examined body length, eye size and forewing length, traits likely targeted
through selection due to light pollution. We examined moths collected over the past 137 years. We predicted decreasing fore-
wing length, body and eye size, in response to increasing light pollution and expected to see trait changes from the past to
today, and from rural to urban areas, representing temporal and spatial gradients of increasing light pollution. In order to deter-
mine current levels of light pollution, we used radiance values of the years 2012 to 2019. These values were the base to extrapo-
late previous radiance values for all sample sites and years. We observed no trait differences along the spatial gradient, but trait
and sex dependant changes along the temporal gradient. We could not confirm a direct causal link between changes in body
size and female eye size. However, we revealed indirect effects of light pollution, and assume habitat fragmentation and host-
plants to be the main drivers for these effects. A trend towards smaller-eyed females in ‘medium’and ‘high’light-polluted areas
over time could be a first indication that morphological trait changes to light pollution are taking place.
© 2021 The Author(s). Published by Elsevier GmbH on behalf of Gesellschaft für Ökologie. This is an open access article
under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Keywords: Agrotis exclamationis; Radiance; Morphological traits; Body length; Eye size; Wing length; Anthropogenic gradient
Introduction
Artificial light at night (ALAN) is widespread, positively
correlated with urbanisation (Sutton, 2003), and increases at
an annual rate of about 26% worldwide (H€
olker et al.,
*Corresponding author.
E-mail addresses: silvia.keinath@mfn.berlin (S. Keinath),
hoelker@igb-berlin.de (F. H€
olker), Johannes.Mueller@mfn.berlin
(J. M€
uller), mo.roedel@mfn.de (M.-O. R€
odel).
https://doi.org/10.1016/j.baae.2021.05.004
1439-1791/© 2021 The Author(s). Published by Elsevier GmbH on behalf of Gesellschaft für Ökologie. This is an open access article under the CC BY-NC-
ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Basic and Applied Ecology 56 (2021) 110 www.elsevier.com/locate/baae
2010a;Kyba et al., 2017b). Because ALAN has been intro-
duced in places, times and at intensities at which it does not
naturally occur, it became a threat to biodiversity
(Gaston, Visser & H€
olker, 2015;H€
olker, Wolter, Perkin &
Tockner, 2010b;Longcore & Rich, 2004), with
respective ecological and evolutionary consequences
(Hopkins, Gaston, Visser, Elgar & Jones, 2018;Navara &
Nelson, 2007;Rich & Longcore, 2006). Insects, especially
moths, seem to be particularly affected by ALAN
(Owens et al., 2020;Van Langevelde, Ettema, Donners,
WallisDeVries & Groenendijk, 2011). In clear nights moths
use celestial light sources such as moon and stars for orienta-
tion (e.g. Baker & Sadovy, 1978). However, they get dis-
tracted by artificial light and often stay trapped flying
around lamps. There they become easy prey to predators or
simply die by exhaustion (Degen et al., 2016;Eisen-
beis, 2006). Natural selection thus should favour individuals
that are less attracted by artificial light sources
(Gaston, Bennie, Davies & Hopkins, 2013), as it was shown
for populations of ermine moths Yponomeuta cagnagella,
where specimens from urban areas show a reduced flight-to-
light behaviour compared to conspecifics from pristine dark-
sky habitats (Altermatt & Ebert, 2016). Morphological trait
changes that reduce flight-to-light behaviour may thus indi-
cate adaptation to ALAN in moths. Flight ability is impor-
tant to meet mates, disperse, escape from predators, and
search for nectar and larval host-plants (Chai & Sryg-
ley, 1990;Scoble, 1992). Longer-winged specimens have
better flight abilities than shorter-winged ones (Beall & Wil-
liams, 1945); and larger specimens have been shown to be
better dispersers than smaller ones (Nieminen, Rita &
Uuvana, 1999;Slade et al., 2013). Specimens with better
flight abilities might be relatively more often attracted by
ALAN, because they cover larger distances and thus the
chances that they come close to artificial light increases
(Van Langevelde et al., 2011). Visual cues are important for
navigation strategies (Wehner, 1984). Although males’mate
detection is primarily based on sex pheromones, visual cues
are additively used for short-distance detection
(Grant, 1987). In females visual cues are important for
selecting host-plants for oviposition (Bernays, 2001).
Moth’s eye size likewise impacts sensitivity to light
(Yack, Johnson, Brown & Warrant, 2007). For instance,
Rutowski, Gisl
en and Warrant (2009) showed that large
moths with relatively larger eyes have more accurate and
more sensitive vision than smaller individuals, and, species
with larger eyes are usually more affected by artificial light
than smaller eyed ones (Van Langevelde et al., 2011). Thus,
increasing ALAN may select for smaller-eyed individuals.
Because trait change takes place across many generations,
it is difficult to observe respective processes within usual
study periods. However, this challenge might be overcome
by examining museum vouchers, which have been collected
over long periods (Doudna & Danielson, 2015;
Keinath, Frisch, M€
uller, Mayer & R€
odel, 2020;
Niemeier, M€
uller, Struck & R€
odel, 2020). Herein we
investigated the moth Agrotis exclamationis. During the last
137 years this species was regularly collected in the German
Berlin-Brandenburg area, a region exhibiting steep temporal
and spatial gradients of light pollution. We hypothesize a
decrease in body size, relative forewing length and eye size
due to less mobility and sensitive vision from low to high
levels of light pollution, in space and time (Fig. 1).
Materials and methods
Study area
Berlin, Germany, is an increasingly urbanizing city
(Antrop, 2000), including growing levels of light pollution
(Kyba et al., 2017b). In contrast, the federal state of Bran-
denburg, a rural area surrounding Berlin, is mostly consist-
ing of agricultural and near-natural environments
(Antrop, 2000;Cochrane & Jonas, 1999). Industrialization
in Berlin started in the beginning of the 19th century
(Ribbe, Bohm, Schich & Schulz, 2002a). Streets and public
places became first artificially illuminated in 1882 (Haub-
ner, 1962). Berlin’s population was steadily increasing and
reached an unrivalled peak in the 1920s (Ribbe, Bohm,
Schich & Schulz, 2002b), comprising a much lower human
population after World War II (Ribbe et al., 2002b). Since
an economic boom starting in the 1950s onward, the human
population and the density and intensity of artificial light
increased (Eisenbeis & H€
anel, 2009;United Nations, 2002).
For instance, Kyba, Kuester and Kuechly (2017a) demon-
strated an increase of lit areas of 2.5% and an increase in
radiance of 7.4% in already lit areas from 2012 to 2016.
Study species
Agrotis exclamationis (Linnaeus, 1758) (Lepidoptera,
Noctuidae) is common and widespread in our study region,
at least over the past 137 years. It is a nocturnal pollinator,
exhibiting forewing length of 15 to 19 mm s and occurs in
grasslands, parks, gardens, glades, ruderal sites, and on for-
est edges, rarely at clearings. It is widespread from Europe
to Asia, and produces two generations from May to July,
and from August to September, the latter comprising smaller
individuals (Ebert, Rennwald & Bartsch, 1997). We only
examined imagines from the first generation to ensure com-
parable traits. Relative to migratory moths, Agrotis exclama-
tionis is a medium mobile species. Jones, Lim, Bell,
Hill and Chapman (2016) show that males cover distances
of up to 6935 m. Females deposit their eggs on host-plants
(Xu, Liu & Zhang, 2013). Larvae are generalist feeders
(Ebert, Rennwald & Bartsch, 1997), and may become crop
and potato pests (Xu et al., 2013). Sexes can be distin-
guished by feathered antennae in males, and string-shaped
antennae in females (Ebert et al., 1997).
2 S. Keinath et al. / Basic and Applied Ecology 56 (2021) 110
Origin of specimens
In total, we examined 79 A. exclamationis (48 females; 31
males), including 37 from the city of Berlin and 41 from the
federal state of Brandenburg; 54 specimens (29 females; 25
males) were museum vouchers (Museum f€
ur Naturkunde,
Berlin and Naturkundemuseum Potsdam), spanning the
years 1880 to 1998; 25 specimens (19 females; 6 males)
were collected in 2017. Museum vouchers from Berlin were
collected in parks, small green spaces, industrial areas and
lakefronts. Vouchers from ruderal Brandenburg were col-
lected around small villages and within larger towns.
Museum labels mentioned that vouchers were collected with
light traps. Recently collected specimens were captured
manually by black light traps on 18 dry grassland sites
within Berlin and two dry grassland sites in Brandenburg
(June to July 2017) (see Appendix C: Table 1). We assume
that museum vouchers were manually picked from light
traps for the respective collections (no passive collection for
ecological studies). Because our species is known to be
mainly attracted by short-wavelengths (Fayle, Sharp &
Majerus, 2007;Somers-Yeates, Hodgson, McGregor, Spald-
ing & Ffrench-Constant, 2013) samples from ‘white’(with a
high proportion of blue light) and ‘black’lights traps (UV
and blue light) should be comparable.
Measurements
Specimens were pinned planar in drawers. Complete
drawers with all specimens were scanned with a SatScanTM
imaging system developed by SmartDrive Ltd., including a
camera with a 0.16x telecentric lens. The camera moves
along rails positioned above the drawer and captures 240
images at precise positions. These images are then ‘stitched’
with SatScan analyse 64 software to produce a single high-
resolution image of the entire drawer (Johnson, Mantle,
Gardner & Backwell, 2013). Body length, and forewing
length measures were taken from these figures using the
ruler tool in Adobe Photoshop (Version: CS 5.1). Standard-
ized body length (SBL) measures were taken with modifica-
tions following Kavanaugh (1979). SBL commonly
comprises head length, thorax length and abdominal length.
We measured abdominal length by summing up all 10 single
segment measures of the abdomen by using the maximum
distance because abdomens of some vouchers were curved
Fig. 1. Hypothetic influence of increasing light pollution on moths’morphological traits. We expect that larger moths with relatively larger
eyes and forewing length will occur at sites and in times with low levels of light pollution. With increasing light pollution, we expect a
decrease in body size, relative eye size, and forewing length.
S. Keinath et al. / Basic and Applied Ecology 56 (2021) 110 3
to one side. For better measures of some segments that were
partly covert by other segments, we used polygon lasso and
magic lasso tools to uncover them. Forewing length (FWL)
were measured from the anterior axillaria joint of the fore-
wing with the thorax along the costa contact with parapteron
episternale to the tip of the forewing. Horizontal diameters
of the eyes were measured with a measuring ocular attached
to a dissecting microscope (Leica MZ 12) (see Appendix
A). Measurement errors were determined by the mean of a
randomized chosen subsample of 10 specimens (accuracy
was: SBL: §0.03 mm; FWL: §0.06 mm; eye diameter: §
0.03 mm). The data used in the analyses were standardized
to SBL: relative mean diameter of the left and right eye (eye
diameter / SBL), and the relative mean length of the left and
right forewings (FWL / SBL).
Data classification
For categorization of ALAN levels at different sites and
years, we used the “light pollution map”(www.lightpollu
tionmap.info)(Light pollution map, 2019), based on satellite
data from the defense Meteorological Satellite Program-
Operational Linescan System (DMSP; 1992 to 2011; spatial
resolution: 5 £5 km), and the Visible Infrared Imaging
Radiometer Suite Day-Night Band (VIIRS DNB; 2012 to
2019; spatial resolution: 750 £750 m, see Miller et al.,
2013). Especially VIIRS DNB has been shown to have suffi-
cient resolution to identify major sources of waste light
(Kyba et al., 2015). The maps based on VIIRS DNB data
were used to display radiance values (10
9
W/cm
2
* sr) for
every verified moth collection site. In contrast, maps based
on DMSP data are classified into light categories. The higher
spatial resolution of DMSP and VIIRS DNB pixel between
different years are sufficient for our analyses because they
match the accuracy of the museum label data, usually given
on Berlin district levels, districts usually being even larger
than the spatial resolution of DMSP pixel.
For moths collected in 2017, we used absolute radiance
values of their respective sampling sites. For moths collected
in previous years (1880 to 2010), we calculated for each col-
lection site the mean relative rate of ALAN increase over
the years 2012 to 2019 from maps that are covered by VIIRS
DNB. With these site-specific ALAN increase rates over
seven years, we back-calculated the ALAN levels of former
years, using time steps of seven years (see Appendix C:
Table 1). To evaluate the reliability of this approach, we val-
idated our calculated radiance values with the map based on
DMSP data from 1998 to 2005. All retrospectively calcu-
lated radiance levels were within the given intervals of the
DMSP light categories of the respective year.
In a next step we established our own Light Pollution Cat-
egories (LPC) of both measured and back-calculated radi-
ance values. Category 1 ‘low’is spanning radiance values
from 0 to 0.25; category 2 ‘medium’from 0.25 to 1.50 and
category 3 ‘high’from 1.5 to 50.0 (10
9
W/cm
2
* sr). We
used ‘LPC’for spatial analyses and temporal analyses for
investigating effects of light pollution on a larger scale.
Statistical analysis
For all analyses we used software of the R-Project, ver-
sion 3.6.3 (R Core Team, 2020). For testing normal distribu-
tion of ‘Radiance’values, we used Shapiro Wilk tests. For
non-normally distributed data, we used Spearman correla-
tions, testing for correlation between ‘Radiance’and ‘Year’
for the entire study region Berlin-Brandenburg (‘Radiance’
~‘Year’) to get a rough overview of the ALAN situation in
the entire region; and separately for the different areas Berlin
(‘Radiance Berlin’~‘Year’) and Brandenburg (‘Radiance
Brandenburg’~‘Year’), respectively.
We tested distribution of our response variables (‘SBL’;
‘eye diameter / SBL’and ‘FWL / SBL’) by visualisation via
QQPlot with the R packages ‘carData’(Fox, Weisberg &
Price, 2019) and ‘MASS’(Venables & Ripley, 2002). With
normal distribution, fitting our data best, we ran linear
regression models for temporal analyses. We used ‘Radi-
ance’,‘Year’and ‘Sex’as factors, tested the interaction
between ‘Year’and ‘Radiance’(Lm = ‘Trait’~‘Year’*
‘Radiance’+‘Sex’), and did the same for testing ‘Light Pol-
lution Categories’(LPC) (Lm = ‘Trait’~‘Year’*
‘LPC’+ Sex).
For spatial analyses we used one-way analyses of vari-
ance (ANOVA), separately for sexes, by using ‘LPC’as
grouping variable (‘Trait’~‘LPC’). We used Pearson corre-
lations, testing for correlation between ‘SBL’and ‘Year’
and between ‘eye diameter / SBL’and ‘Year’, both sepa-
rately for males and females. For visualization, we used
ggplot2 with the R-package ggplot2 (Wickham, 2016).
Results
The Spearman correlation between ‘Radiance’and ‘Year’
for the entire study region, Berlin-Brandenburg, was signifi-
cant (S= 31,308; rho = 0.619; p<0.001), indicating a con-
tinuous increase of light pollution over time. This
correlation was equally significant for the sub-regions,
although the correlations were weaker; Berlin: S= 5505.6;
rho = 0.398; p= 0.013; and Brandenburg: S= 6664.1;
rho = 0.420; p= 0.006 (Fig. 2).
We detected no significant effect of ‘Radiance’on any of
the investigated traits. However, body size differed between
sexes (Lm: df = 74; t=4.070; p<0.001) and changed
over years (Lm: df = 74; t= 2.402; p= 0.019). Size of both
sexes was significantly positively correlated with ‘Years’
(Pearson correlation: females: t= 2.687; df = 46;
R
2
= 0.368; p= 0.010; males: t= 2.348; df = 29;
R
2
= 0.400; p= 0.026), i.e. body size increased over time
but not in response to ‘Radiance’(Fig. 3A). Likewise, rela-
tive eye size differed between sexes (Lm: df = 74; t= 7.757;
4 S. Keinath et al. / Basic and Applied Ecology 56 (2021) 110
p<0.001), and changed over years (Lm: df = 74;
t=2.474; p= 0.016). Females’eye size was significant
negatively correlated with ‘Years’(Pearson correlation:
t=2.502; df = 46; R2 = 0.346; p= 0.016), whereas the
negative correlation in males’eye size between ‘Years’was
non-significant. Thus, females’relative eye size decreased
over time but again, not in response to ‘Radiance’(Fig. 3B).
Relative forewing length did not differ between sexes and
did not change over years (see Appendix B: Table 1).
We found no significant effect of ‘Light Pollution Catego-
ries’(LPC) (‘high’;‘medium’and ‘low’) on any of the
investigated traits in our temporal analyses. However, there
was a trend for relative eye size (Lm: df = 74; t=1.949;
p= 0.055), indicating smaller-eyed females in ‘medium’
and ‘high’LPCs compared to ‘low’LPCs (Fig. 4). The inter-
action between ‘LPC’and ‘Year’indicated also a trend (Lm:
df = 74; t= 1.988; p= 0.051), showing that increasing
‘LPCs’across years have an influence on the trend of
decreasing eye size (see Appendix B: Table 2). We found
no significant effect in our spatial analysis. Body size, rela-
tive eye size and forewing length did not differ between
areas with ‘low’,‘medium’and ‘high’light pollution cate-
gories. This absence of any effects was detected in males as
well as in females (see Appendix B: Table 3).
Discussion
Increasing artificial light at night (ALAN) is known to
have consequences on nocturnal moths, because they are
distracted by artificial light. Therefore, natural selection
should favour individuals that are less impacted by ALAN
(Van Langevelde et al., 2011), what could lead to intraspe-
cific morphological trait changes.
In our study we focused on spatio-temporal changes in
body size, relative eye size and forewing length in the moth
Agrotis exclamationis in response to different ALAN levels
within the Berlin-Brandenburg area, Germany. We predicted
smaller-sized specimens with relatively shorter forewings
and smaller eye size in areas and times with high levels of
ALAN than in less impacted areas and times.
Generally, we observed that A. exclamationis displayed sex-
ual dimorphism in body and relative eye size, but not in fore-
wing length. Body size increased in both sexes, whereas relative
eye size decreased only in females over the past 137 years. Both
effects could not be verified as a direct response to ALAN.
However, we detected a trend towards smaller eye size in
females when ALAN levels increased over time. No changes
were observed in forewing length in both sexes over time, and
no differences occurred in any trait along the spatial gradient.
The lack of trait changes in response to increasing ALAN
across space and time was unexpected and needs explana-
tion. First, all of our specimens were captured with light
traps. Thus, our specimens may have shown a pronounced
flight-to-light behaviour, whereas we may have missed indi-
viduals with a reduced flight-to-light behaviour. Only a
light-independent collecting method like pheromone traps,
traps based on floral compounds (T
oth et al., 2010) or mal-
aise traps (Hallmann et al., 2017) might clarify that point.
However, such vouchers were not available.
Fig. 2. Radiance values taken from the light pollution maps for the year 2017 (www.lightpollutionmap.info), and back-calculated radiance
values for the years 1880 to 2010 for moth collecting sites from the Berlin-Brandenburg region, Germany. Significant p-values of Spearman
correlation are given in bold.
S. Keinath et al. / Basic and Applied Ecology 56 (2021) 110 5
Another reason for the absence of effects in response to
increasing ALAN across time might be due to our study’s
timeframe. Although it is known that intraspecific morpho-
logical trait change in response to human induced environ-
mental changes may arise across relatively short timeframes
in insects (Keinath et al., 2020;Van’t Hof, Edmonds, Dali-
kova, Marec & Saccheri, 2011), and even vertebrates
(Doudna & Danielson, 2015;Niemeier et al., 2020), most
evolutionary processes are depending on longer times than
our 137 years study period. However, in another moth intra-
specific behavioural adaptations in reduced flight-to-light
behaviour apparently already took place in urban areas
(Altermatt & Ebert, 2016); as a consequence, morphological
trait changes might follow.
A further reason for the lack of any light-driven trait
changes could be due to inaccuracy of our retrospectively
computed rates of ALAN. The further back the radiance cal-
culations reached, the less certain these values might be. For
instance, we based our calculations on the ass, umption of
continuous change. However, ALAN levels were already
high during the economic boom in the 1920s (Ribbe et al.,
2002b), followed by a drastic decrease during World War II.
Furthermore, the spectral quality of ALAN changed over
time, due to the application of different light sources
(Gaston, Davies, Bennie & Hopkins, 2012;Kyba et al.,
2015). Finally, the accuracy of localities on labels and
thus our assignment of light intensity might have failed
to reach the necessary precision, as even on a relatively
small-scale light intensity can vary a lot (Kuechly et al.,
2012).
An indirect hint that increasing ALAN influences our
study species would be a decline in A. exclamationis’abun-
dance over time in areas with high ALAN impact, and a sta-
ble population in less impacted areas. Unfortunately, such
data are not available. However, Conrad, Warren, Fox,
Parsons and Woiwod (2006) show a decline in A. exclama-
tionis across 35 years in lit areas of Britain, and discuss
increasing ALAN as one a responsible factor.
We believe that our assumptions of ALAN impacting our
study species are realistic. When examining changes in
Fig. 3. Morphological trait change in Agrotis exclamationis over years. (A) body size (SBL), and (B) eye diameter (eye diameter / SBL) over
the years 1880 to 2017 with red or light grey (females) and blue or dark grey (males) confidence intervals and smoothed regression lines from
linear models and Pearson correlation coefficients. Significant p-values are given in bold. (For interpretation of the references to color in this
figure legend, the reader is referred to the web version of this article.).
6 S. Keinath et al. / Basic and Applied Ecology 56 (2021) 110
response to Light pollution categories (LPC), we indeed found a
trend towards smaller-eyed females in ‘medium’and ‘high’
light polluted areas over time. These categories are larger-scaled
than radiance values and could make changes more visible. We
interpret this trend as a first indicator that morphological trait
changes in response to ALAN are already taking place (com-
pare Van Langevelde et al., 2011).
However, it remains to be discussed why this trend was
only found in females and not in males. During our most
recent sampling, more females were captured than males.
This might be a hint that females are more sensitive to
ALAN. In contrast, Williams (1939) could show that male
A. exclamationis are significantly more often attracted by
light traps, making this explanation unlikely. Moreover, we
found a decrease in females’eye size across time but not
verifiable in response to radiance values and not in males.
Male moths have larger eyes than females (Yagi &
Koyama, 1963) because they are depending on visual cues
for detecting females in near distance (Grant, 1987). The
change of male eye size might be opposed by other selection
pressures, i.e. less effective escape from predators and/or
mate detection. Females in Lepidoptera are indeed known to
be less dependant on their eyes for mating, instead females
use vision (amongst other senses) for host-plant detection
and oviposition (Bernays, 2001). Agrotis exclamationis is a
generalist and therefore depending on high sensory capacity
because they have to recognize and choose between broader
ranges on host-plants than specialists (Bernays & Wci-
slo, 1994;Dall & Cuthill, 1997;Levins & MacArthur, 1969).
Interestingly, Callahan (1957) shows that the noctuid moth
Heliothis zea seemed to be unable to recognize host-plants
for oviposition when artificially illuminated, probably
because light was reflected from green plants. Thus, in areas
with high ALAN levels females’view on their host-plants
might be impacted, favouring selection for females with
smaller eyes which are less disrupted by ALAN. Addition-
ally, a change of plant composition due to human-estab-
lished plant species in our anthropogenically influenced
study area (Sukopp & Werner, 1983;Zerbe, Maurer,
Schmitz & Sukopp, 2002) could be a reason for females’
decrease in eye size probably due to a diluting effect of their
native, established host-plant species.
We also predicted body size and relative forewing length
to become smaller with higher ALAN levels because speci-
mens that are more mobile may encounter and consequently
become distracted by artificial light more often (Chai &
Srygley, 1990;Rutowski et al., 2009;Van Langevelde et al.,
2011). Our findings revealed increased body size in both
sexes over time, but not in response to ALAN. We found no
changes in forewing length in both sexes.
Merckx, Kaiser and Van Dyck (2018) demonstrate increas-
ing body size in macro-moths due to increasing habitat frag-
mentation in urban areas. Thus, over the 137 years covered
in our study, increasingly fragmented habitats due to urbani-
sation in Berlin Antrop (2000), and intensified agriculture in
Brandenburg (Cochrane & Jonas, 1999), could have
opposed the potential effects of ALAN. Interestingly, it has
been shown that attraction radii of streetlights overlap in
most cases, building barriers for moths (Degen et al., 2016).
Therefore, ALAN might have increased the fragmentation
of nocturnal habitats, also in our study area, limiting moth
dispersal, and thus, indirectly inducing changes in body size
but not in relative forewing length.
Our results revealed that trait and sex-depended changes
in A. exclamationis over the past 137 years in the Berlin-
Brandenburg region took place. However, these changes
could not be directly linked to increasing ALAN. Neverthe-
less, we assume trait changes to have been indirectly
induced by ALAN as a result of habitat fragmentation
(Degen et al., 2016)andfemales’changed perception of
host-plants (Callahan, 1957). However, we found a trend
of sex-dependant changes in eye size which may be
directly related to different levels of light pollution, and
thus a first sign of light pollution driving morphological
trait change.
Funding
This work was funded by the German Federal Ministry of
Education and Research BMBF within the Collaborative
Project “Bridging in Biodiversity Science BIBS”(funding
number 16LC1501F1).
Fig. 4. Mean diameter of right and left eyes in relation to Standard-
ized Body Size (eye diameter / SBL) over time (arrow) with differ-
ent light pollution categories (low, medium, high) of females
(reddish or light grey boxplots) and males (blue or dark grey box-
plots). Numbers within boxplots give sample sizes. (For interpreta-
tion of the references to color in this figure legend, the reader is
referred to the web version of this article.).
S. Keinath et al. / Basic and Applied Ecology 56 (2021) 110 7
Declaration of Competing Interest
None.
Acknowledgement
We thank D. Berger (Naturkundemuseum, Potsdam), S.
Buchholz (Technische Universit€
at, Berlin: Institute for Ecol-
ogy; Ecosystem Science / Plant Ecology), and Manfred
Gerstberger (ORION association, Berlin) for supplying
specimens. We further thank V. Richter for support with col-
lection work, F. Tillack for support with laboratory work,
and B. Schurian (all Museum f€
ur Naturkunde, Berlin) for
introducing to the SatScan system and SatScan analyse 64
software. The permission for sampling invertebrates in Ber-
lin was issued by Senatsverwaltung f€
ur Umwelt, Verkehr
und Klimaschutz, City of Berlin.
Supplementary materials
Supplementary material associated with this article can
be found in the online version at doi:10.1016/j.
baae.2021.05.004.
References
Altermatt, F., & Ebert, D. (2016). Reduced flight-to-light behavior
of moth populations exposed to long-term urban light pollution.
Biology Letters,12, 20160111 https://dx.doi.org/10.1098/
rsbl.2016.0111.
Antrop, M. (2000). Changing patterns in the urbanized countryside
of western Europe. Landscape Ecology,15, 257–270.
doi:10.1023/A:1008151109252.
Baker, R. R., & Sadovy, Y. (1978). The distance and nature of
light-trap response of moths. Nature,276, 818–821.
doi:10.1038/276818a0.
Beall, G., & Williams, C. B. (1945). Geographic variation in the
wing length of Danaus plexippus (Lep. Rhopalocera). In Pro-
ceedings of the royal entomological society of London (pp.
6576). doi:10.1111/j.1365-3032.1945.tb01068.x.
Bernays, E. A. (2001). Neural limitations in phytophagous insects:
Implications for diet breadt and evolution of host affiliation.
Annual Reviews of Entomology,46, 703–727. doi:10.1146/
annurev.ento.46.1.703.
Bernays, E. A., & Wcislo, W. T. (1994). Sensory capabilities,
information-processing, and resource specialization. The Quar-
terly Review of Biology,69, 187–204. doi:10.1086/418539.
Callahan, S. P. (1957). Oviposition response of the imago of the
Corn Earworm Heliothis zea (Boddie), to various wave lengths
of light. Annals of the Entomological Society of America,50,
444–452. doi:10.1093/aesa/50.5.444.
Chai, P., & Srygley, R. B. (1990). Predation and the flight, mor-
phology, and temperature of neotropical rain-forest butterflies.
The American Naturalist,135, 748–765. doi:10.1086/285072.
Cochrane, A., & Jonas, A. (1999). Reimagining Berlin: World city,
national capital or ordinary place? European Urban and
Regional Studies,6, 145–164 https://doi.org/
10.1177%2F096977649900600204.
Conrad, F. K., Warren, S. M., Fox, R., Parsons, S. M., &
Woiwod, P. I. (2006). Rapid declines of common, widespread
British moths provide evidence of an insect biodiversity crisis.
Biological Conservation,132, 279–291. doi:10.1016/j.bio-
con.2006.04.020.
Dall, S. R. X., & Cuthill, I. C. (1997). The information costs of
generalism. Oikos (Copenhagen, Denmark),80, 197–202.
doi:10.2307/3546535.
Degen, T., Mitesser, O., Perkin, K. E., Weiß, N.-S., Oehlert, M.,
Matting, E., et al. (2016). Street lighting: Sex-independent
impacts on moth movement. Journal of Animal Ecology,85,
1352–1360. doi:10.1111/1365-2656.12540.
Doudna, J. W., & Danielson, B. J. (2015). Rapid morphological
change in the masticatory structures of an important ecosystem
service provider. PloS ONE,10, e0127218. doi:10.1371/jour-
nal.pone.0127218.
Ebert, G., Rennwald, E., & Bartsch, D. (1997). Die Schmetterlinge
Baden-W€
urttembergs. Band 5 - Nachtfalter III. Stuttgart: Ulmer
Verlag.
In Eisenbeis, G. (2006). Artificial night lighting and insects: Attrac-
tion of insects to streetlamps in a rural setting in Germany.
(Eds.), In C. Rich, & T. Longcore (Eds.), Ecological conse-
quences of artificial night lighting In. (pp. 281304). Wash-
ington: Island Press (pp..
Eisenbeis, G., & H€
anel, A. (2009). Light pollution and the impact
of artificial night lighting on insects. (Eds.),
In M. J. McDonnell, A. H. Hahs, J. H. Breuste (Eds.), Ecology
of cities and towns (Eds.). (pp. 243263). Cambridge: Cam-
bridge University Press.
Fayle, M. T., Sharp, E. R., & Majerus, N. E. M. (2007). The effect
of moth trap type on catch size and composition in British Lepi-
doptera. British Journal of Entomology and Natural History,
20, 221–232.
Fox, J., Weisberg, S., & Price, B. (2019). An R companion to
applied regression (3rd edition). https://cran.r-project.org/pack
age=carData.
Gaston, K. J., Bennie, J., Davies, T. W., & Hopkins, J. (2013). The
ecological impacts of night-time light pollution: A mechanistic
appraisal. Biological Reviews,88, 912–927. doi:10.1111/
brv.12036.
Gaston, K. J., Davies, T. W., Bennie, J., & Hopkins, J. (2012).
Reducing the ecological consequences of night-time light pollu-
tion: Options and developments. Journal of Applied Ecology,
49, 1256–1266 https://doi: 10.1111/j.1365-2664.2012.02212.x.
Gaston, K. J., Visser, M. E., & H€
olker, F. (2015). The biological
impacts of artificial light at night: The research challenge. Phil-
osophical Transactions of the Royal Society B,370, 20140133.
doi:10.1098/rstb.2014.0133.
Grant, G. G. (1987). Copulatory behaviour of spruce budworm,
Choristoneura funiferana (Lepidoptera: Tortricidae): Experi-
mental analysis of the role of sex pheromone and associated
stimuli. Annals of the Entomological Society of America,80,
78–88. doi:10.1093/aesa/80.1.78.
Hallmann, A. C., Sorg, M., Jongejans, E., Siepel, H., Hofland, N.,
Schwan, H., et al. (2017). More than 75 percent decline over
27 years in total flying insects’biomass in protected areas.
PLoS ONE,12, e0185809. doi:10.1371/journal.pone.0185809.
8 S. Keinath et al. / Basic and Applied Ecology 56 (2021) 110
Haubner, F. (1962). Aus den Anf€
angen der €
Offentlichen Elektri-
zit€
atsversorgung Berlin (1882-1899). Zeitschrift f€
ur Firmenge-
schichte und Unternehmerbiographie,1,1–11. doi:10.1515/
zug-1962-0102.
H€
olker, F., Moss, T., Griefahn, B., Kloas, W., Voigt, C. C.,
Henckel, D., et al. (2010a). The dark side of light: A transdisci-
plinary research agenda for light pollution policy. Ecology and
Society,15 Art. 4. https://www.jstor.org/stable/26268230.
H€
olker, F., Wolter, C., Perkin, E. K., & Tockner, K. (2010b). Light
pollution as a biodiversity threat. Trends in Ecology and Evolu-
tion,25, 681–682 https://dx.doi.org/10.1016/j.
tree.2010.09.007.
Hopkins, R. G., Gaston, J. K., Visser, E. M., Elgar, A. M., &
Jones, M. T. (2018). Artificial light at night as a driver of evolu-
tion across urban-rural landscapes. Frontiers in Ecology and
the Environment,16, 472–479. doi:10.1002/fee.1828.
Johnson, L., Mantle, L. B., Gardner, L. J., &
Backwell, R. Y. P. (2013). Morphometric measurements of
dragonfly wings: The accuracy of pinned, scanned and detached
measurement methods. ZooKeys,276,77–84. doi:10.3897/zoo-
keys.276.4207.
Jones, C. B. H., Lim, S. K., Bell, R. J., Hill, K. J., &
Chapman, W. J. (2016). Quantifying interspecific variation in
dispersal ability of noctuid moths using an advanced tethered
flight technique. Ecology and Evolution,6, 181–190.
doi:10.1002/ece3.1861.
Kavanaugh, D. H. (1979). Studies on the Nebriini (Coleoptera:
Carabidae), III. New Nearctic Nebrza species and subspecies.
Proceedings of the California Academy of Science,42,87–
133.
Keinath, S., Frisch, J., M€
uller, J., Mayer, F., &
R€
odel, M.-O. (2020). Spatio-temporal color differences
between urban and rural populations of a ground beetle during
the last 100 years. Frontiers in Ecology and Evolution - Urban
Ecology,7. doi:10.3389/fevo.2019.00525 Art. 525.
Kuechly, H. U., Kyba, C. C., Ruhtz, T., Lindemann, C., Wolter, C.,
Fischer, J., et al. (2012). Aerial survey and spatial analysis of
sources of light pollution in Berlin, Germany. Remote Sensing
of Environment,126,39–50. doi:10.1016/j.rse.2012.08.008.
Kyba, C. C. M., Garz, S., Kuechly, H., De Miguel, A. S.,
Zamorano, J., Fischer, J., et al. (2015). High-resolution imagery
of earth at night: New sources, opportunities and challenges.
Remote Sensing,7,1–23. doi:10.3390/rs70100001.
Kyba, C. C. M., Kuester, T., & Kuechly, U. H. (2017a). Changes in
outdoor lighting in Germany from 2012 to 2016. International
Journal of Sustainable Lighting,19, 112–123. doi:10.26607/
ijsl.v19i2.79.
Kyba, C. C. M., Kuester, T., S
anchez de Miguel, A., Baugh, K.,
Jechow, A., H€
olker, F., et al. (2017b). Artificially lit surface of
Earth at night increasing in radiance and extent. Science Advan-
ces,3, e1701528. doi:10.1126/sciadv.1701528.
Levins, R., & MacArthur, R. (1969). An hypothesis to explain the
incidence of monophagy. Ecology,50, 910–911. doi:10.2307/
1933709.
Longcore, T., & Rich, C. (2004). Ecological light pollution. Fron-
tiers in Ecology and the Environment,2, 191–198.
doi:10.1890/1540-9295(2004)002[0191:ELP]2.0.CO;2.
Merckx, T., Kaiser, A., & Van Dyck, H. (2018). Increased body
size along urbanization gradients at both community and intra-
specific level in macro-moths. Global Change Biolology,24,
3837–3848. doi:10.1111/gcb.14151.
Light pollution map (2019). Interactive world light pollution map.
www.lightpollutionmap.info. Accessed 06 Mai 2020.
Miller, D.S., Straka, W., Mills, P.S., Elvidge, D.C., Lee, F.T., Sol-
brig, J. et al. (2013). Illuminating the capabilities of the Suomi
natural Polar-Orbiting Partnership (NPP) Visible Infrared Radi-
ometer Suite (VIIRS) day/night band. Remote Sensing,5,
67176766. https://doi.org/10.3390/rs5126717
Navara, K. J., & Nelson, J. R. (2007). The dark side of light at
night: Physiological, epidemiological, and ecological conse-
quences. Journal of Pineal Research,43, 215–224.
doi:10.1111/j.1600-079X.2007.00473.x.
Niemeier, S., M€
uller, J., Struck, U., & R€
odel, M.-O. (2020). Super-
frogs in the city: 150 year impact of urbanization and agricul-
ture on the European Common Frog. Global Change Biology,
26, 6729–6741 https//doi.org/10.1111/gcb.15337.
Nieminen, M., Rita, H., & Uuvana, P. (1999). Body size and
migration rate in moths. Ecography,22, 697–707. doi:10.1111/
j.1600-0587.1999.tb00519.x.
Owens, C. S. A., Cochard, P., Durrant, J., Farnworth, B.,
Perkin, K. E., & Seymoure, B. (2020). Light pollution is a
driver of insect decline. Biological Conservation,241, 108259.
doi:10.1016/j.biocon.2019.108259.
R Core Team. (2020). R: A language and environment statistical
computing. Vienna: R Foundation for Statistical Computing
URL https://www.R-project.org/.
Ribbe, W., Bohm, E., Schich, W., & Schulz, K. (2002a).
Geschichte berlins. Band 1: Von der fr€
uhgeschichte bis zur
industrialisierung.M
€
unchen: Beck.
Ribbe, W., Bohm, E., Schich, W., & Schulz, K. (2002b).
Geschichte berlins. Band 2: Von der m€
arzrevolution bis zur
gegenwart.M
€
unchen: Beck.
Rich, C., & Longcore, T. (2006). Ecological consequences of artifi-
cial night lighting. Washington: Island Press.
Rutowski, R. L., Gisl
en, L., & Warrant, E. J. (2009). Visual acuity
and sensitivity increase allometrically with body size in butter-
flies. Arthropod Structure and Development: (pp. 91100)38.
doi:10.1016/j.asd.2008.08.003.
Scoble, M. J. (1992). The Lepidoptera: Form, function and diver-
sity. Oxford, UK: Oxford University Press.
Slade, E. M., Merckx, T., Riutta, T., Bebber, D. P., Redhead, D.,
Riordan, P., et al. (2013). Life-history traits and landscape char-
acteristics predict macro-moth responses to forest fragmenta-
tion. Ecology,94, 1519–1530. doi:10.1890/12-1366.1.
Somers-Yeates, R., Hodgson, D., McGregor, P. K., Spalding, A., &
Ffrench-Constant, R. (2013). Shedding light on moths: Shorter
wavelengths attract noctuids more than geometrids. Biology
Letters,9, 20130376. doi:10.1098/rsbl.2013.0376.
Sukopp, H., & Werner, P. (1983). Urban environments and vegeta-
tion. (Eds.), In W. Holzner, M. J. A. Werger, I. Ikusima (Eds.),
Man’s impact on vegetation (Eds.). The Hague: Dr. W. Junk
Publishers.
Sutton, P. C. A. (2003). A scale adjusted measure of ‘urban sprawl’
using nighttime satellite imagery. Remote Sensing of Environ-
ment,86, 353–369. doi:10.1016/S0034-4257(03)00078-6.
T
oth, M., Szaruk
an, I., Dorogi, B., Guly
as, A., Nagy, P., &
Rozgonyi, Z. (2010). Male and female Noctuid Moths attracted
to synthetic lures in Europe. Journal of Chemical Ecology,36,
592–598. doi:10.1007/s10886-010-9789-z.
United Nations (2002). World population prospects: The 2001
revision. Population division of the department of economic
and social affairs of the United Nations Secretariat.
S. Keinath et al. / Basic and Applied Ecology 56 (2021) 110 9
Van Langevelde, F., Ettema, A. J., Donners, M.,
WallisDeVries, F. M., & Groenendijk, D. (2011). Effect of
spectral composition of artificial light on the attraction of moths.
Biological Conservation,144, 2274–2281. doi:10.1016/j.bio-
con.2011.06.004.
Van’t Hof, A., Edmonds, E., Dalikova, M., Marec, F., &
Saccheri, J. I. (2011). Industrial melanism in British Pep-
pered Moths has a singular and recent mutational origin.
Science (New York, N.Y.),332, 958–960. doi:10.1126/sci-
ence.1203043.
Venables, W. N., & Ripley, B. D. (2002). Modern applied statistics
with s (4th ed.). New York: Springer-Verlag https://www.stats.
ox.ac.uk/pub/MASS4.
Wehner, R. (1984). Astronavigation in insects. Annual Review of
Entomology,29, 277–298 https://doi.org/10.1146/annurev.
en.29.010184.001425.
Wickham, H. (2016). ggplot2: Elegant graphics for data analysis.
New York: Springer-Verlag.
Williams, C. B. (1939). An analysis of four years captures of
insects in a light trap. Part 1. General survey; sex proportion;
phenology; and time of flight. Transactions of the Royal Ento-
mological Society of London,89,79–132.
Xu, J., Liu, N., & Zhang, R. (2013). Major potato pests in China.
(Eds.), In P. Giordanengo, C. Vincent, A. Alyokhin (Eds.),
Insect pests of potatos Global perspectives on biology and
management (Eds.). New York: Elsevier.
Yack, J. E., Johnson, S. E., Brown, S. G., & Warrant, E. J. (2007).
The eyes of Macrosoma sp. (Lepidoptera: Hedyloidea): A noc-
turnal butterfly with superposition optics. Arthropod Structure
and Development,36,11–22. doi:10.1016/j.asd.2006.07.001.
Yagi, N., & Koyama, N. (1963). The compound eye of lepidoptera:
Approach from organic evolution. Tokyo: Shinkyo Press.
Zerbe, S., Maurer, U., Schmitz, S., & Sukopp, H. (2002). Biodiver-
sity in Berlin and its potential for nature conservation. Land-
scape and Urban Planning,62, 139–148. doi:10.1016/S0169-
2046(02)00145-7.
Available online at www.sciencedirect.com
ScienceDirect
10 S. Keinath et al. / Basic and Applied Ecology 56 (2021) 110
