Content uploaded by Jae Chun Choe
Author content
All content in this area was uploaded by Jae Chun Choe on Jun 21, 2015
Content may be subject to copyright.
ORIGINAL PAPER
Functional values of stabilimenta in a wasp spider, Argiope
bruennichi: support for the prey-attraction hypothesis
Kil Won Kim &Kyeonghye Kim &Jae C. Choe
Received: 23 March 2012 /Revised: 27 August 2012 / Accepted: 4 September 2012 / Published online: 15 September 2012
#Springer-Verlag 2012
Abstract Many orb-weaving spiders decorate their webs
with conspicuous ultraviolet (UV)-reflective stabilimenta.
The prey-attraction hypothesis suggests that stabilimenta
are visually attractive to prey and thus may increase the
spiders’foraging success. However, previous studies on
the function of stabilimenta have produced conflicting
results in Argiope species. Using a combination of field
and laboratory studies, we examined whether the linear
stabilimentum of Argiope bruennichi contributes to prey
interception. We recorded prey interceptions in 53 webs
with stabilimenta and 37 equally-sized webs without stabi-
limenta, classifying captured prey according to their taxo-
nomical group and size. On average, 6.2 ± 4.7 prey items
were intercepted in webs with stabilimenta, while 3.2±2.9
items were intercepted in webs without stabilimenta. The
effects of stabilimenta on foraging success appear to be due
to increased interception of UV-sensitive insect pollinators,
including 20 families of Diptera, Hymenoptera, Coleoptera,
and Lepidoptera. The mean number of UV-sensitive prey was
4.4±3.6inwebswithstabilimentacomparedwith1.8±2.1in
webs without stabilimenta. Webs with and without stabili-
menta did not differ in the mean number of UV-nonsensitive
prey captured. The linear stabilimentum showed strong posi-
tive effects on the interception of large prey: webs with
stabilimenta captured more than twice as many large prey
(≥5 mm) than webs without stabilimenta, whereas there was
only a slight difference in the interception rates for small prey
(<5 mm). Comparisons among different Argiope species sug-
gest that the stabilimentum may have different adaptive func-
tions in different species or ecological contexts.
Keywords Stabilimentum .Prey-attraction hypothesis .
Argiope bruennichi
Introduction
Many orb web-weaving spiders (Araneae: Araneidae,
Tetragnathidae, Uloboridae) decorate their webs with species-
typical structures called stabilimenta (Simon 1895; Herberstein
et al. 2000;Bruce2006). A stabilimentum is a conspicuous
white silk structure that reflects much more ultraviolet (UV)
light than other spider silks in the web (Craig and Bernard
1990). This is surprising, given that web-building spiders’silk
generally has low UV-reflectance, presumably to reduce the
visibility of webs to insect prey (Blackledge and Wenzel 2000).
Researchers have proposed many hypotheses concerning
the functionof the stabilimentum. The stabilimentum has been
proposed to mechanically stabilize and strengthen the orb web
(Robinson and Robinson 1970), camouflage the spider by
obscuring its outline (Schoener and Spiller 1992;Eberhard
2003), prevent web damage by larger animals (Eisner and
Nowicki 1983), increase foraging success by attracting more
prey to the web (Craig and Bernard 1990;Tso1998), help
with thermoregulation by providing a sunshade for spiders
foraging in high-temperature sites (Humphreys 1992), protect
the spider from predatory attacks via concealment or by
increasing the apparent size of the spider (Eberhard 1973;
Lubin 1975), serve as a platform for molting (Simon 1895;
Robinson and Robinson 1978; Nentwig and Heimer 1987),
Communicated by D. Kemp
K. W. Kim (*)
Division of Life Sciences, University of Incheon,
Incheon 406-772, Republic of Korea
e-mail: kilwon@incheon.ac.kr
K. Kim
Kim and Chang Intellectual Property Law Firm,
Seoul 100-784, Republic of Korea
J. C. Choe
Division of EcoScience, Ewha Womans University,
Seoul 120-750, Republic of Korea
Behav Ecol Sociobiol (2012) 66:1569–1576
DOI 10.1007/s00265-012-1410-8
function as guides to lead males to females for mating (Crome
and Crome 1961), or imitate gaps in vegetation produced by
the sun and sky, natural sources of UV light (Craig and
Bernard 1990).
A few hypotheses concerning the functional values of the
stabilimentum have been tested directly by experimental
manipulations, but the results have been contradictory or
unclear and differ depending on the spider species examined
(Herberstein et al. 2000;Bruce2006;WalterandElgar
2012). A recent and well-received hypothesis, the “prey-
attraction hypothesis,”suggests that the stabilimentum may
function to increase foraging success by attracting more
prey to webs (Craig and Bernard 1990;Tso1998;
Watanabe 1999). Stabilimenta might increase the foraging
success of web-building spiders, because web decorations
may attract insect pollinators seeking flower nectar by
reflecting UV light similar to UV-reflecting flowers.
A possible evolutionary mechanism by which such func-
tions could evolve is offered by the sensory exploitation
hypothesis, which was initially proposed to explain how
sexual selection by female choice operates (Ryan 1998).
This hypothesis predicts that preexisting biases in the
receiver’s sensory system (for example, attraction to specific
colors of food, specific sounds, etc.) may incidentally affect
decisions that an animal makes when dealing with other
behavioral challenges. Decorating the web with a stabili-
mentum, accordingly, might be an example of the exploita-
tion of a preexisting sensory bias in a prey animal toward
UV-reflective surfaces that allows orb-weaving spiders to
profit via increased foraging success (Bruce et al. 2001).
The results of several studies of spiders in the Araneid genus
Argiope have offered support for the prey-attraction hypothesis
(e.g., Argiope trifasciata,Tso1996;Argiope aetherea, Elgar et
al. 1996;Argiope appensa, Hauber 1998;Argiope aurantia,
Tso 1998;Argiope keyserlingi,Herberstein2000, Bruce et al.
2001;Argiope versicolor,Li2005;Argiope savignyi,Gálvez
2009), while other studies involving spiders in the same genus,
and in some case the same species, have yielded results that do
not support the prey-attraction hypothesis (e.g., A. trifasciata,
Blackledge 1998;A. aurantia, Blackledge 1998, Blackledge
and Wenzel 2000;A. bruennichi, Prokop and Grygláková
2005;A. appensa,Adamatetal.2011).
Most researchers testing the prey-attraction function of
stabilimenta have measured the average number of flying
insects intercepted in webs with and without stabilimenta in
the laboratory or in the field. However, a number of method-
ological problems with these studies have been noted (Bruce
2006). Webs with stabilimenta are often smaller than webs
without stabilimenta (Hauber 1998; Bruce et al. 2004; but see
Prokop and Grygláková 2005), and some researchers did not
control for the effects of web size when assessing the effects of
stabilimenta on prey capture rates (Bruce 2006). Previous
studies have also failed to differentiate between prey species
sensitive to UV light (hereafter referred to as UV-sensitive
prey) and UV-nonsensitive species when counting the number
of prey items intercepted in the webs. Previous studies have
also generally not considered the energy content of prey
captured in different types of webs (one large prey item
captured in one type of web could contain more nutrients than
several small prey items captured in a web of a different type)
or the effects of the sites on which webs were built (webs with
stabilimenta may occur in sites with a different prey density or
the spider may consider the natural background when design-
ing its web; Bruce 2006). Past experience in prey capture
could also influence web design (Herberstein et al. 2000;
Venner et al. 2000;Adamatetal.2011).
In this study, we examine the prey-attraction function of
stabilimenta in Argiope bruennichi which is abundant in
paddy fields, wetlands, and shrub areas in South Korea.
We hypothesized that webs with stabilimentum would cap-
ture more UV-sensitive prey that webs without stabilimen-
tum. Using a combination of field and laboratory studies, we
compared prey interception rates between webs with stabi-
limenta and webs without stabilimenta while carefully con-
trolling for the effects of potentially confounding variables.
We measured the web structure and classified prey intercep-
ted in the webs by taxonomy and size.
Materials and method
Study species
A. bruennichi (Scopoli 1772) (Araneidae), also known as the
wasp spider, is a panpalearctic orb web-building spider.
Individuals reach maturity and reproduce in August and
September. Females (2.0–2.5 cm) are much larger than males
(0.8–1.2 cm), and show clear yellow and black bands on their
abdomen like many other members of the genus Argiope.
The female spider builds a spiral orb web at dawn or
dusk, usually in long grass with small shrubs a little above
ground level. After they finish building the orb spirals, A.
bruennichi individuals decorate their webs with stabilimenta
placed in a vertical linear pattern through the center of the
web (Fig. 1). A stabilimentum is made using a densely
woven zigzag stitch and consists of two parts: an upper
stabilimentum and a lower stabilimentum. A. bruennichi
do not always decorate their webs, and the number and size
of silk bands placed on their webs vary on a daily basis.
Therefore, spiders can be found on webs without stabili-
menta, on webs with one-armed stabilimenta consisting of a
lower part or an upper part only, or on webs with both the
upper and lower parts of the stabilimentum. Stabilimenta are
constructed from the same silk used by orb-web spiders to
wrap prey, which originates from the aciniform and piriform
glands (Walter et al. 2008).
1570 Behav Ecol Sociobiol (2012) 66:1569–1576
Collection and rearing
We collected adult female A. bruennichi along a paddy field
in Hwa-seong, Kyung-gi, South Korea (126°50′N 37°11′E;
altitude: 30–70 m) during August and September and im-
mediately transported them to the laboratory. We placed
each individual in a square wooden frame (500×500×
150 mm) custom-designed for orb-web spiders with remov-
able front and back glass covers. The spiders were kept in
laboratory environments at 25 ± 1 °C and 100 lx illumination
with a 12:12 h light/dark cycle. We humidified the inner
sides of the cage twice per day with a spray, and provided
the females with juvenile crickets, Teleogryllus emma.
Web measurement
The spiders built their webs overnight in the laboratory. After
removing the front and back glass covers from the cage, we
photographed the webs with a black velvet background to
measure the following parameters: web area, stabilimentum
area, radial length, number of spirals, and mesh size (Fig. 1).
To minimize possible influences of web size on prey capture
rates (Prokop and Grygláková 2005), we selected webs with
stabilimenta and webs of similar size without stabilimenta for
our experiments. For webs with stabilimenta, we only included
webs that had both an upper and a lower stabilimentum. We
excluded webs built by females that had produced an egg sac,
because physiology of the spider may influence the decoration
characteristics (Walter and Elgar 2012).
To estimate web size, we measured the outermost and inner-
most diameters of each web from the sticky spirals (Fig. 2).
Web area was then calculated as: web area0π× 1/2 outer-
most diameter×1/2 innermost diameter. As the stabilimen-
tum of A. bruennichi is a ladder-form, stabilimentum area
was calculated as length×(upper width + lower width of the
stabilimentum) / 2. Mean radius length was calculated from
the lengths of the maximum and minimum radii. The
number of spirals was measured as the number of sticky
silk circles from the center of the web to the outermost
radius. The mesh size (average distance between spirals)
was calculated as (maximum radius / (number of spirals
at that area−2) + minimum radius / (number of spirals at
that area –2))/2.
Field data collection
We removed the glass covers from the cages and in-
stalled the cages containing the webs built in the labo-
ratory on the ground surface in the field site (an
artificial pond bounded by weeds). We placed similar
numbers of webs with and without stabilimenta in al-
ternating order at 150 (±15)-cm intervals along the edge
of the artificial pond. Field data collection was con-
ducted on 10 clear days in September after cloudy days
and rainy days were excluded because of difficulties of
the field work and prey species variability.
We observed prey interceptions by the webs during
trialslasting5heach,beginningbetween0930and
1000 hours. We collected all prey struggling within
the webs immediately and stored them in ethanol for
later identification. We identified all prey to the family
level and categorized prey body size as “small prey”
(<5 mm) or “large prey”(≥5mm).
Fig. 1 Web o f A. bruennichi built in a square wooden frame (500 ×
500× 150 mm). The spider decorates its web with stabilimenta placed
in a vertical linear pattern through the center of the web
Fig. 2 Illustration of the web measurement in A. bruennichi. I and O:
innermost diameter and outermost diameter of a web, Rand R′: max-
imum and minimum radii, Uand L: upper and lower width of a
stabilimentum, M: mesh size
Behav Ecol Sociobiol (2012) 66:1569–1576 1571
Data analysis
Basically, we used nonparametric statistics in StatView 5.0
(2005). We present, however, the data mean and standard
deviation instead of medians and inter-quartile ranges. We
compared the number of prey intercepted in webs with and
without stabilimenta using Mann–Whitney Utests. We then
compared rates of prey interception for different taxonomic
groups of prey using Wilcoxon signed-rank tests. We used
regression analysis with ANOVA to examine the relationships
between the number of prey intercepted and stabilimentum
area, web area, number of spirals, and mean radius length. We
used the Mann–Whitney Utest to compare web structures
(web area, mean length of radii, number of spirals, and mesh
size) and the mean numbers of small and large prey intercep-
ted between webs with and without stabilimenta.
Results
We investigated prey interceptions for 53 webs with stabili-
menta and 37 webs without stabilimenta. A total of 450 prey
animals were captured: 331 in webs with stabilimenta and
119 in webs without stabilimenta. The mean number of prey
captured per web was 5.0 ± 4.3 (n090).
The prey interception was affected by the presence of a
stabilimentum. On average, 6.2±4.7 prey animals were inter-
cepted in a single web with stabilimentum, while 3.2± 2.9
were intercepted in a web without stabilimentum (Fig. 3a;
Mann–Whitney Utest: n1053, n2037, z04.059, p<0.0001).
There was a significant difference in the interception of UV-
sensitive prey between webs with stabilimenta and webs with-
out stabilimenta. An average of 4.4±3.6 UV-sensitive prey
were captured in webs with stabilimenta, compared with 1.8±
2.1 captured in webs without stabilimenta (Fig. 3b;Mann–
Whitney Utest: n1053, n2037, z04.576, p<0.0001). There
was no difference in interception rates for UV-nonsensitive
prey species in webs with and without stabilimenta (Fig. 3c;
Mann–Whitney Utest: n1053, n2037, z00.221, p00.8248): a
mean of 1.8± 2.9 prey were intercepted in webs with stabili-
menta and 1.4± 1.6 in webs without stabilimenta.
Classification of the prey
The 450 prey animals intercepted in the webs belonged to
29 family groups (Table 1). Insects in Dipteran families
were the most commonly captured prey, comprising
50.7 % (228 preys) of the total prey intercepted.
Comparison of the number of prey intercepted in webs
with and without stabilimenta paired by family showed
different patterns in different taxonomic groups. Prey be-
longing to the 20 families of Diptera, Hymenoptera,
Coleoptera, and Lepidoptera (Table 1) were significantly
more likely to be captured by webs with stabilimenta than
webs without stabilimenta: mean capture rate 00.21 ± 0.48
items/web in webs with stabilimenta vs. 0.09 ± 0.21 items/
web in webs without stabilimenta (Wilcoxon signed-rank
test: n10n2020, p<0.01). On the other hand, there was no
significant difference in interception rates for the eight fam-
ilies belonging to Homoptera, Hemiptera, and Orthoptera:
0.24±0.24 items/web in webs with stabilimenta vs. 0.17 ±
0.18 in webs without stabilimenta (Wilcoxon signed-rank
test: n10n208, p>0.05).
Number of prey interceptions
0
4
8
12
16
Number of UV-sensitive prey
0
2
4
6
8
10
12
Without stabilimentum With stabilimentum
Number of UV-non-sensitive prey
0
2
4
6
8
10
12
a
b
c
Fig. 3 Comparison between webs with stabilimenta and webs without
stabilimenta. aThe number of prey interceptions per web; bthe
number of UV-sensitive prey; cthe number of UV-nonsensitive prey.
The median and 5th, 25th, 75th, and 95th percentiles are shown in the
box plots
1572 Behav Ecol Sociobiol (2012) 66:1569–1576
Stabilimentum area vs. prey interception
The mean stabilimentum area for webs with stabilimenta
was 3.0±1.4 cm
2
(n053). The area of the stabilimentum was
a significant predictor of the rate of prey interception
(Fig. 4). When the area of stabilimentum increased, more
prey were intercepted in the web (ANOVA test for regression
analysis: F
1,51
06.922, R
20
0.12, p00.0112).
Web structure
As we deliberately chose webs of similar size with stabili-
menta and without stabilimenta for our field experiments
before the webs were installed in the field site, there was no
significant difference in the web area between webs with
and without stabilimenta (Table 2). The mean length of radii
and mesh size also did not differ in webs with and without
stabilimenta (Table 2). However, webs with stabilimenta
had more spirals on average than webs without stabilimenta
(Table 2). When the number of spirals increased, the rate of
prey interception increased both in webs with stabilimentum
(ANOVA test for regression analysis: F
1,51
07.400, R
2
0
0.127, p00.0089) and without stabilimentum (F
1,35
0
9.356, R
2
00.211, p00.0042).
We grouped the data for webs with and without stabili-
menta to examine the influence of the web structure on the
number of prey intercepted. The number of prey intercepted
was significantly positively related to the web area
(ANOVA for regression analysis: F
1,88
026.024, R
2
00.228,
Table 1 Classification of prey intercepted in the web of A. bruennichi.
Ninety webs were observed in total including 53 webs with stabili-
menta and 37 webs without stabilimenta
Prey classification Total number
of prey items
intercepted
Mean number of prey per web
With
stabilimentum
Without
stabilimentum
Diptera
Tipulidae: crane flies etc. 10 0.17 0.03
Chironomidae: nonbiting
midges etc.
146 2.13 0.89
Muscidae: house flies etc. 15 0.23 0.08
Drosophilidae: fruit flies etc. 43 0.66 0.22
Culicidae: mosquitoes etc. 7 0.11 0.03
Syrphidae: hoverflies etc. 7 0.13 0.00
Hymenoptera
Andrenidae: mining Bees etc. 2 0.02 0.03
Apidae: honey bees etc. 3 0.04 0.03
Ichneumonidae: ichneumon
wasps etc.
29 0.32 0.32
Formicidae: ants etc. 4 0.04 0.05
Vespidae: paper wasps etc. 3 0.06 0.00
Braconidae: parasitoid
wasps etc.
1 0.02 0.00
Sphecidae: digger wasps etc. 1 0.02 0.00
Pompilidae: spider wasps etc. 1 0.02 0.00
Coleoptera
Chrysomelidae: leaf beetles etc. 6 0.11 0.00
Scarabaeidae: scarab beetles etc. 3 0.02 0.05
Staphylinidae: rove beetles etc. 1 0.00 0.03
Lepidoptera
Pyralidae: snout moths etc. 5 0.09 0.00
Arctiidae: tiger moths etc. 1 0.02 0.00
Lycaenidae: gossamer-winged
butterflies etc.
1 0.00 0.03
Homoptera
Cicadellidae: leafhoppers etc. 1 0.00 0.03
Aphidoidea: aphids etc. 41 0.47 0.43
Delphacidae: planthoppers etc. 37 0.42 0.41
Hemiptera
Pentatomidae: stink bugs etc. 11 0.15 0.08
Orthoptera
Gryllidae: true crickets etc. 5 0.06 0.05
Tetrigidae: grouse locusts etc. 46 0.66 0.30
Tettigoniidae: katydids etc. 1 0.02 0.00
Acarina: mites etc. 11 0.17 0.05
Unclassified prey 8 0.09 0.08
Diptera, Hymenoptera, Coleoptera, and Lepidoptera were classified as
UV-sensitive, while Homoptera, Hemiptera, Orthoptera, Acarina clas-
sified as UV-nonsensitive prey (Ioannides and Horridge 1975;
Silberglied 1979; Wakakuwa et al. 2007)
Fig. 4 The number of prey intercepted plotted against stabilimentum
area
Table 2 Comparison of web structures between webs with stabili-
menta and webs without stabilimenta in A. bruennichi (mean ± SD)
Web
structural
variable
Webs with
stabilimenta
(n053)
Webs without
stabilimenta
(n037)
Mann–Whitney
Utest
Web area (cm
2
) 669.6±303.8 600.6 ± 278.8 z00.964, p00.3353
Mean length of
radii (cm)
14.3± 3.4 13.9 ± 3.4 z00.521, p00.6026
Number of spirals 35.7± 11.3 26.5± 8.4 z04.034, p<0.0001
Mesh size (cm) 0.44± 0.10 0.48± 0.11 z01.415, p00.1572
Behav Ecol Sociobiol (2012) 66:1569–1576 1573
p<0.0001; Fig. 5a), the number of spirals (F
1,88
024.598,
R
2
00.218, p<0.0001; Fig. 5b), and the mean radius length
(F
1,88
019.249, R
2
00.179, p<0.001; Fig. 5c). On the other
hand, the mesh size was not related to the number of prey
intercepted (F
1,88
02.710, p00.1033).
Prey size
Prey items of different sizes were intercepted at different rates.
A total of 197 small (<5 mm) and 253 large (≥5 mm) prey
were captured. The proportion of large prey intercepted in a
single web was 0.41± 0.28 and small, 0.59±0.28. Larger prey
items were captured more than twice as frequently in webs
with stabilimenta than webs without stabilimenta (Table 3,p<
0.0001). Differences were slight in capture rates for small-
sized prey in webs with and without stabilimenta (Table 3).
Only 22 (4.9 %) out of 450 prey captured were >10 mm in
size, consisting of 16 prey in 53 webs with stabilimentum and
6 prey in 37 webs without stabilimentum. Difference in inter-
ception of prey larger than 10 mm was not statistically
approved (p00.2169).
Discussion
Our results support the prey-attraction hypothesis for the
function of the stabilimentum in A. bruennichi. More prey
items were intercepted in webs with stabilimenta than in
equally sized webs without stabilimenta. The stabilimentum
increased spider foraging success via an enhanced rate of
interception of UV-sensitive insect pollinators, including 20
families of Diptera, Hymenoptera, Coleoptera, and
Lepidoptera. Our results are in line with the results done in
A. trifasciata (Tso 1996), A. aetherea (Elgar et al. 1996), A.
appensa (Hauber 1998), A. aurantia (Tso 1998), A. key-
serlingi (Herberstein 2000; Bruce et al. 2001), A. versicolor
(Li 2005), and A. savignyi (Gálvez 2009).
Results of our study are, however, different from those of a
study done in A. bruennichi in grassland habitat in Slovakia (49°
28′N, 19°23′E; Prokop and Grygláková 2005). Prokop and
Grygláková (2005) measured the number of prey captured every
30 min for 6 h in 31 webs with stabilimenta and 12 webs without
stabilimenta. They did not find a difference in prey capture rates
between webs with and without stabilimenta. These differences
observed in the same species might be due to behavioral differ-
ences between populations in Slovakia (Central Europe) and
South Korea (East Asia) isolated by distance and other geo-
graphic barriers over the long term. Alternatively, the result may
be explained by differences in the characteristics of insect prey
between the two field sites. Prokop and Grygláková (2005)
reported that more than 40 % (webs with stabilimenta, 45 %;
webs without stabilimenta, 43 %) of insects captured were
Orthopterans, while Diptera comprised 50.7 % of the total
number of prey intercepted in our study.
As noted by Prokop and Grygláková (2005), stabilimen-
tum building might be more beneficial in grasshopper-poor
habitats where flies constitute a greater part of spiders’
potential prey. Another possible element is that the differ-
ence in results may be due to methodological differences.
Prey interceptions were observed at intervals of 30 min in
the study of Prokop and Grygláková (2005). Small flying
insects could be quickly devoured in place by the spider and
thus go unreported, which might produce a bias in the
results. Moreover, the study of Prokop and Grygláková’s
(2005) only included 12 webs without stabilimenta. This
small sample size might make it difficult to statistically
Tab l e 3 The number of small (<5 mm) and large (≥5mm)prey
intercepted per web with vs. without a stabilimentum (mean ± SD)
Prey Web
with stabilimentum
(n053)
without stabilimentum
(n037)
Mann–Whitney
Utest
Small 2.6±3.0 1.6± 1.8 z01.911,
p00.0560
Large 3.6±2.4 1.6± 1.7 z04.481,
p<0.0001
Fig. 5 The number of prey intercepted plotted against web area (a), the number of spirals (b), and mean radius length (c); webs with and without
stabilimenta were grouped together for these analyses
1574 Behav Ecol Sociobiol (2012) 66:1569–1576
detect real differences in prey capture rates between webs
with and without stabilimenta.
In this study, we propose another advantage resulting from
the building of stabilimenta by orb-weaving spiders. The sta-
bilimentum of A. bruennichi had a strong effect on rates of
capture for larger prey items: webs with stabilimenta captured
more than twice as many large (≥5 mm) prey than webs without
stabilimenta, while there was only a slight difference in capture
rates for small (<5 mm) prey. Previous studies have largely
neglected to consider the energy content of the prey. The
stabilimentum may also mechanically stabilize and strengthen
the orb web (Robinson and Robinson 1970). Spiders decorat-
ing their webs with stabilimenta at higher frequencies might
expect to accumulate more energy by capturing larger flying
insects, eventually resulting in higher growth rates (Li 2005).
The Araneid spider-genus Argiope is cosmopolitan with
76 currently known species. Argiope spiders show high
diversity in their stabilimentum design both between and
within species (Seah and Li 2002; Walter and Elgar 2012).
Furthermore, different species and populations decorate
their webs with stabilimenta at different frequencies, and
individuals alter their decorating behavior on a daily basis
(Bruce 2006; we observed such variability within individu-
als even when the spiders built webs in the laboratory.)
Comparisons among different Argiope species suggest the
possibility that the adaptive importance of stabilimentum
usage may vary across species and ecological contexts.
There are many potential functions of stabilimenta. The
evolutionary origin of this trait in the genus Argiope may
have to be separated from its contemporary role (Walter and
Elgar 2012). Whereas the original function of stabilimenta
in A. bruennichi is probably not the prey-attraction, this
study demonstrates that their presence enhances prey cap-
ture, at least in some ecological circumstances.
Acknowledgments For help in data collection and field research sup-
port, we thank Byunghyuk Kim, Sanha Kim, Seungtae Kim, and Hyo-
jeong Kim. We are also grateful to Susan Lappan for helpful comments
on the manuscript. This work was supported by Korea Research Foun-
dation Grant funded by the Korean Government (KRF-2008-331-
C00270), the Ewha Global Top 5 Grant 2011 of Ewha Womans Univer-
sity, and the University of Incheon Research Grant (2011).
References
Adamat LA, Torres MAT, Gorospe JA, Barrion-Dupo ALA, Demayo CG
(2011) Orb-web design of garden spider, Argiope appensa (Walck-
enaer, 1841) (Araneae: Araneidae). Aust J Basic Appl Sci 5:175–184
Blackledge TA (1998) Stabilimentum variation and foraging success in
Argiope aurantia and Argiope trifasciata (Araneae, Araneidae). J
Zool 246:21–27
Blackledge TA, Wenzel JW (2000) The evolution of cryptic spider silk:
a behavioral test. Behav Ecol 11:142–145
Bruce MJ (2006) Silk decorations: controversy and consensus. J Zool
269:89–97
Bruce MJ, Herberstein ME, Elgar MA (2001) Signalling conflict
between prey and predator attraction. J Evol Biol 14:786–794
Bruce MJ, Heiling AM, Herberstein ME (2004) Web decorations and
foraging success in Araneus eburnus (Araneae: Araneidae). Ann
Zool Fennici 41:563–575
Craig CL, Bernard GD (1990) Insect attraction to ultraviolet reflecting
spider webs and web decorations. Ecol 71:616–623
Crome W, Crome I (1961) Paarung und Eiablage bei Argiope bruen-
nichi (Scopoli) auf Grund von Freilandbeobachtungen an zwei
Populationen im Spreewald/Mark Brandenburg (Araneae: Aranei-
dae). Mitt Zool Mus Berlin 37:189–252
Eberhard WG (1973) Stabilimenta on the webs of Uloborus diversus
(Araneae: Uloboridae) and other spiders. J Zool Lond 171:367–384
Eberhard WG (2003) Substitution of silk stabilimenta for egg sacs by
Allocyclosa bifurca (Araneae: Araneidae) suggests that silk stabi-
limenta function as camouflage devices. Behaviour 140:847–868
Eisner T, Nowicki S (1983) Spider web protection through visual
advertisement: role of the stabilimentum. Science 219:185–187
Elgar MA, Allan RA, Evans TA (1996) Foraging strategies in orb-spinning
spiders: ambient light and silk decorations in Argiope aetherea
Walckenaer (Araneae:Araneoidea). Aust J Ecol 21:464–467
Gálvez D (2009) Frame-web-choice experiments with stingless bees
support the prey-attraction hypothesis for silk decorations in
Argiope savignyi. J Arachnol 37:249–253
Hauber M (1998) Web decorations and alternative foraging tactics of
the spider Argiope appensa. Ethol Ecol Evol 24:47–57
Herberstein ME (2000) Foraging behavior in orb-web spiders
(Araneidae): do web decorations increase prey capture success
in Argiope keyserlingi Karsch, 1878? Aust J Zool 48:217–223
Herberstein ME, Craig CL, Coddington JA, Elgar MA (2000) The
functional significance of silk decorations of orb-web spiders: a
critical review of the empirical evidence. Biol Rev 75:649–669
Humphreys WF (1992) Stabilimenta as parasols: shade construction by
Neogea sp. (Araneae: Araneidae: Argiopinae) and its thermal
behaviour. Bull Br Arachnol Soc 9:47–52
Ioannides AC, Horridge GA (1975) The organization of visual fields in
the hemipteran acone eye. Proc R Soc Lond B Biol Sci 190:373–391
Li D (2005) Spiders that decorate their webs at higher frequency intercept
more prey and grow faster. Proc R Soc B 272:1753–1757
Lubin YD (1975) Stabilimenta and barrier webs in the orb webs of
Argiope argentata (Araneae, Araneidae) on Daphne and Santa
Cruz islands, Galapagos. J Arachnol 2:119–126
Nentwig W, Heimer S (1987) Ecological aspects of spider webs. In: Nentwig
W (ed) Ecophysiology of spiders. Springer, Berlin, pp 211–225
Prokop P, Grygláková D (2005) Factors affecting the foraging success
of the wasp-like spider Argiope bruennichi (Araneae): role of web
design. Biol Bratislava 60:165–169
Robinson B, Robinson MH (1970) The stabilimentum of the orb-web
spider Argiope argentata: an improbable defense against preda-
tors. Can Entomol 102:641–655
Robinson B, Robinson MH (1978) Developmental studies of Argiope
argentata (Fabricius) and Argiope aemula (Walckenaer). Symp
Zool Soc Lond 42:31–40
Ryan MJ (1998) Sexual selection, receiver biases, and the evolution of
sex differences. Science 281:1999–2003
Schoener TW, Spiller DA (1992) Stabilimenta characteristics of
the spider Argiope argentata on small islands: support of
the predator-defense hypothesis. Behav Ecol Sociobiol
31:309–318
Seah WK, Li D (2002) Stabilimentum variations in Argiope versicolor
(Araneae: Araneidae) from Singapore. J Zool Lond 258:531–540
Silberglied RE (1979) Communication in the ultraviolet. Ann Rev Ecol
Syst 10:373–398
Simon E (1895) Histoire naturelle des Araignées, Vol. 1, fasc. 4.
Libraire Encyclopédique de Roret, Paris
StatView (2005) SAS Institute Inc. Cary, NC
Behav Ecol Sociobiol (2012) 66:1569–1576 1575
Tso IM (1996) Stabilimentum of the garden spider Argiope trifasciata:
a possible prey attractant. Anim Behav 52:183–191
Tso IM (1998) Isolated spider web stabilimentum attracts insects.
Behaviour 135:311–319
Venner S, Pasquet A, Leborgne R (2000) Web-building behaviour in
the orb weaving spider Zygiella x-notata: influence of experience.
Anim Behav 59:603–611
Wakakuwa M, Stavenga DG, Arikawa K (2007) Spectral organization of
ommatidia in flower-visiting insects. Photochem Photobiol 83:27–34
Walter S, Elgar MA (2012) The evolution of novel animal sig-
nals: silk decorations as a model system. Biol Rev 87:686–
700
Walter A, Elgar MA, Bliss P, Moritz RFA (2008) Wrap attack
activates web decorating behavior in Argiope spiders. Behav
Ecol 19:799–804
Watanabe T (1999) The influence of energetic state on the form of
stabilimentum built by Octonoba sybotides (Araneae: Ulobori-
dae). Ethology 105:719–725
1576 Behav Ecol Sociobiol (2012) 66:1569–1576
