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The wasp spider Argiope bruennichi (Arachnida, Araneidae): Ballooning is not an obligate life history phase


Aerial dispersal (''ballooning'') of Argiope bruennichi spiderlings has been claimed to be an obligate life history trait and a prerequisite for spinning prey-capture webs. If this were true, a bal-looning phase would be essential for any laboratory rearing of A. bruennichi making rearing protocols particularly elaborate. We tested the significance of ballooning for second-instar spiderlings in the labo-ratory and showed that the ballooning behavior is not essential for building prey-capture orb webs. Our results also give no evidence for the hypothesis that recent natural selection has changed ballooning behavior in newly founded field populations. Ballooning is a common dispersal mecha-nism for many modern spiders (Coyle 1983; Dean & Sterling 1985; Weyman 1993), and this behavior is particularly important for maintaining genetic cohesion among Argiope populations (Ramirez & Haakonsen 1999). The life history of Argiope is characterized by ballooning, the aerial transport on wind-blown silk threads. A good example for the impor-tance of ballooning for range expansion is the Palearctic wasp spider Argiope bruennichi (Scopoli 1772). The spider is an r-strategist (Guttmann 1979), characterized by high aerial dispersal capability and an ongoing postgla-cial expansion of its geographical range in Eu-rope (van Helsdingen 1982). Females of A. bruennichi produce up to five cocoons in the field, often containing several hundred eggs (Crome & Crome 1961; Köhler & Schäller 1987). The expansion of the species has ac-celerated in the second half of the last century probably due to factors favoring dispersal by ballooning (Guttmann 1979; Levi 1983; Sach-er & Bliss 1990; Scharff & Langemark 1997; Jonsson & Wilander 1999; Smithers 2000). The wasp spider prefers grassy or herbaceous vegetation in open, ephemeral or shrubby sites (Wiehle 1931; Pasquet 1984; Malt 1996) in coarse-grained (patchy) landscapes (Gillandt 1 Corresponding author.
2005. The Journal of Arachnology 33:516–522
Andre´ Walter, Peter Bliss
and Robin F.A. Moritz: Institut fu¨r Zoologie, Martin-
Luther-Universita¨t Halle-Wittenberg, Hoher Weg 4, D-06120 Halle (Saale), Germany.
ABSTRACT. Aerial dispersal (‘‘ballooning’’) of Argiope bruennichi spiderlings has been claimed to be
an obligate life history trait and a prerequisite for spinning prey-capture webs. If this were true, a bal-
looning phase would be essential for any laboratory rearing of A. bruennichi making rearing protocols
particularly elaborate. We tested the significance of ballooning for second-instar spiderlings in the labo-
ratory and showed that the ballooning behavior is not essential for building prey-capture orb webs. Our
results also give no evidence for the hypothesis that recent natural selection has changed ballooning
behavior in newly founded field populations.
Keywords: Araneae, ballooning experiment, laboratory rearing, web-building behavior.
Ballooning is a common dispersal mecha-
nism for many modern spiders (Coyle 1983;
Dean & Sterling 1985; Weyman 1993), and
this behavior is particularly important for
maintaining genetic cohesion among Argiope
populations (Ramirez & Haakonsen 1999).
The life history of Argiope is characterized by
ballooning, the aerial transport on wind-blown
silk threads. A good example for the impor-
tance of ballooning for range expansion is the
Palearctic wasp spider Argiope bruennichi
(Scopoli 1772). The spider is an r-strategist
(Guttmann 1979), characterized by high aerial
dispersal capability and an ongoing postgla-
cial expansion of its geographical range in Eu-
rope (van Helsdingen 1982). Females of A.
bruennichi produce up to five cocoons in the
field, often containing several hundred eggs
(Crome & Crome 1961; Ko¨hler & Scha¨ller
1987). The expansion of the species has ac-
celerated in the second half of the last century
probably due to factors favoring dispersal by
ballooning (Guttmann 1979; Levi 1983; Sach-
er & Bliss 1990; Scharff & Langemark 1997;
Jonsson & Wilander 1999; Smithers 2000).
The wasp spider prefers grassy or herbaceous
vegetation in open, ephemeral or shrubby sites
(Wiehle 1931; Pasquet 1984; Malt 1996) in
coarse-grained (patchy) landscapes (Gillandt
Corresponding author.
& Martens 1980; Sacher & Bliss 1989) and
has regionally benefited from an extension of
farming production and urbanization (Loh-
meyer & Pretscher 1979; Arnold 1986; Nyf-
feler & Benz 1987). River valleys have been
identified as favored dispersal corridors fur-
ther supporting the importance of ballooning
for dispersion (Gauckler 1967; Puts 1988).
Follner & Klarenberg (1995) claimed bal-
looning to be an obligate phase in the devel-
opment of A. bruennichi. These authors mon-
itored the pre-ballooning and ballooning
behavior of spiderlings in a grassland study
site near Munich (Germany). Since they never
found aggregations of orb webs in the neigh-
borhood of the cocoons from which the over-
wintering second instar spiderlings eclosed
and they only observed the construction of
first prey-capture orb webs after a ballooning
trip, they concluded ‘‘that aeronautic behav-
iour in Bavarian populations of A. bruennichi
is obligatory’’. Moreover, these authors sug-
gested that spiderlings, which have hatched
from the cocoon, will starve to death, unless
they perform a ballooning trip. Ballooning
should thus be an obligate phase to switch
from a non-predatory, passive phase to one of
active predation by spinning prey-capture
orbs. Follner & Klarenberg (1995) argued that
the obligatory aerial dispersal might be a re-
sult of recent natural selection and be the rea-
Figures 1–4.—Design and course of the ballooning experiment. The spiderlings were placed on a spatula
(sp) and exposed to a light air current by a fan (ve) and heat source (hs), which were placed at the left
edge of a lab bench (240 cm). After cutting the drag line the spiderlings became airborne to land on the
lab bench, which served as a landing strip (ls). 1. Pre-ballooning behavior: sp
spatula; ve
(light breeze); hs
heat source (25 Watt lamp, distance to spatula
20 cm); sh
spiderling hanging
from a dragline; bt
ballooning thread. 2. Initial ballooning phase. 3. Airborne spiderling: ls
strip’’ (lab bench of 240 cm length). 4. Landing phase.
son behind the swift expansion of the species.
New populations which are established during
a period of expansion are always founded by
individuals, which have ballooned.
If ballooning were a truly obligate phase, it
would not only be important for natural selec-
tion but also be important for any rearing pro-
tocol for A. bruennichi. Allowing for balloon-
ing in a rearing procedure might easily render
laboratory breeding unfeasible as it could
prove to be too time-consuming and laborious.
However, an obligate ballooning phase has
never been observed before, neither in other
Argiope nor in the generally well studied A.
bruennichi. Tolbert (1976, 1977) studied bal-
looning behavioral elements of A. trifasciata
(Forska˚l 1775) and A. aurantia Lucas 1833.
He concluded from field and laboratory ob-
servations that ‘‘it is unnecessary for spider-
lings of either Argiope species to engage in
aerial dispersal before building an orb web’’
(Tolbert 1977), which is an obvious discrep-
ancy to Follner’s and Klarenberg’s (1995)
claims. We here test the significance of bal-
looning for the construction of the first prey-
capture web in the laboratory by comparing
spiderlings reared under two experimental
conditions, one with and one without balloon-
We collected cocoons of A. bruennichi (n
6) in dry and semi-dry grasslands north-
east of Halle (Saale) in late April 2002 (Ger-
many, 160 m a.s.l., 51
N, 011
E). They were maintained in the lab in indi-
vidual glass vials (9 cm diameter, 13 cm
height, coated with fine gauze) at 23
and mist-sprayed with water every two days
to avoid desiccation. The vial bottom was
covered with initially wet cellulose wadding
(1 cm). Second-instar spiderlings hatched
from the cocoons in early May.
One day after hatching we simulated indi-
vidual ballooning for 60 spiderlings (10 from
each cocoon) by exposing the spiderling on a
spatula to an air stream generated by a heat
source and a fan (see Figs. 1–4 for details of
the experimental design). We observed behav-
ioral elements in the pre-ballooning phase in
detail and noticed its mode. When the spider-
ling became airborne, we tracked it and re-
trieved it at the ‘‘landing strip’’ (Figs. 3, 4).
The ballooning experiment was repeated im-
mediately (re-ballooning) for each individual
to satisfy a possible ‘‘ballooning drive’’ (see
Tolbert 1977). The spiderlings had to actively
participate in this experiment by showing the
entire sequence of pre-ballooning and bal-
looning behavior (Figs. 1–4).
Following the experiments, the ‘‘balloon-
ers’’ were kept in the same unheated indoor
room with windows admitting indirect natural
light. They were housed in groups (n
in three gauze covered glass terraria (50
31 cm; 25
C; 65
10% RH) and fed
ad libitum 45–50 live Drosophila melanogas-
ter once a day. Every two days we sprinkled
the inside surfaces of the terraria with water.
This prevented desiccation and allowed for
Figure 5.—Web-building activity of the A. bruennichi spiderlings during laboratory rearing for both
ballooners and non-ballooners.
normal drinking behavior of the spiderlings.
The bottoms of the terraria were covered with
a layer of commercial, pasteurized potting soil
(3 cm) with grass tufts, some dry twigs and
wooden skewers to enhance the number of po-
tential attachment points for web building.
A control group of spiderlings (n
60) was
treated in the same way, but without the bal-
looning procedure (‘‘non-ballooners’’). In
both groups (ballooners vs. non-ballooners)
spiderlings and orb webs were noted three
times daily at 6 a.m., 12 p.m. and 6 p.m. to
ensure individual based data sets. The rearing
period was cut off after 19 days when all the
surviving individuals had spun their first prey-
capture orb-webs.
Voucher specimens are deposited in the En-
tomological Collection of the Martin-Luther-
University Halle-Wittenberg (Zoological In-
stitute), Germany (identification number
The web-building activity of the spiderlings
increased in both the ballooners and the non-
ballooners over time and reached 90
5% for
ballooners (n
54, three terraria) and 95
5% for non-ballooners (n
57, three terraria)
within a period of 19d (Fig. 5). The differ-
ences in the web-building activity (Fig. 5)
were not statistically significant between the
two groups of spiderlings (Kruskal-Wallistest,
0.7515; tested for daily built-first webs).
The mean latency time for web-building (time
from hatching from the cocoon to the con-
struction of the first prey-capture web) was
4.28 days and 8.18
3.60 days for
ballooners (n
54) and non-ballooners (n
57) respectively. This difference was not sta-
tistically significant (t-test, P
Although mortality increased in the second
half of the observation period (Fig. 6), it did
not exceed 22% at the end of the experiment
(ballooners: 21.7
2.89%, n
13, non-bal-
looners: 20.0
8.66%, n
12, difference not
significant, t-test, P
0.77). The surviving
animals caught prey in their orb webs and
showed normal development with up to four
molts within the experimental time.
Using our protocol, we could initiate the
full sequence of ballooning behavior promptly
in every experiment. The A. bruennichi spi-
derlings always showed an identical sequence
of pre-ballooning and ballooning behavior
(Fig. 1–4). When exposed to the heat from the
lamp, they displayed the ‘‘ballooning drive’
Figure 6.—Mortality of the A. bruennichi spiderlings during laboratory rearing.
behavior. Individuals walked to the margin of
the spatula, spooled out a dragline and
dropped down hanging from the line. While
suspended and holding on to the drag line,
they let out an additional line of 50–100 cm
ballooning silk (Fig. 1). When this was lifted
by the breeze generated by the fan and the
heat source, the spiderlings cut the dragline
and became airborne (Figs. 2, 3). After land-
ing (Fig. 4) they hauled in the ballooning line,
formed it with the legs into a silk blob and
finally ate the silk, bringing the ballooning be-
havioral sequence to completion.
Tolbert (1977) observed two modes of
preparation for ballooning in sympatric field
populations of A. trifasciata and A. aurantia.
A spiderling attempting to become airborne
climbed to the top of some blade of grass or
other structures and adopted the typical ‘‘tip-
toe’’ posture by depressing the cephalothorax
and elevating the opisthosoma. Multiple silk
lines were then exuded from the spinnerets.
When moving air generated sufficient silk, the
spiderling became a ‘‘ballooner’’ (Nielsen
1932; Richter 1970; Eberhard 1987). Alter-
natively, the spiderling could become airborne
by dropping and hanging from a dragline,
spinning a ballooning thread, which then grad-
ually lifted and lengthened in the breeze. The
ballooner then cut the dragline and floated off
into the air (Nielsen 1932; Bristowe 1939).
Argiope bruennichi can display both pre-
ballooning modes. However, the drop and
dragline mediated ballooning seems to be
more frequent (Follner & Klarenberg 1995).
In the field, second-instar spiderlings usually
attach the draglines to tips of grass blades or
they use silk threads which connect the tips
of grass haulms as attaching points (Follner &
Klarenberg 1995). In our experiments, we of-
fered individual spiderlings optimal starting
conditions, and we never observed the tip-toe
ballooning mode. Follner (1994) suggested
that ‘‘tip-toe’’ might be a tactical alternative
for individuals in unfavorable starting points
(e.g., overcrowded tips of grass blades).
Our results show that it is not necessary for
spiderlings of A. bruennichi to engage in ae-
rial dispersal before building a prey-capture
web. While ballooning is frequent in the field
(Follner & Klarenberg 1995), it is clearly not
an obligate part in the development of this
species. In spite of the rapid expansion of the
species over the past decades and the potential
importance of aerial dispersal for colonizing
new habitats, the role of ballooning in A.
bruennichi does not differ from A. trifasciata
and A. aurantia where this phase in life his-
tory is also not obligate (Tolbert 1977).
The mortality of about 20% after 19 days
in both experimental groups (difference statis-
tically not significant) suggests that rearing of
A. bruennichi spiderlings to adulthood may be
challenging. Our rearing method based on a
diet with Drosophila melanogaster, similar to
Mu¨ller & Westheide (1993), worked well for
our purpose, where we only tested the effects
of ballooning in second-instar spiderlings on
their ability to make their first web.
On average, more then eight days elapsed
before A. bruennichi spiderlings began to
build their first prey-capture web. This ap-
pears to be a surprisingly long period, because
the animals can only feed once the first web
is built. We cannot exclude that this is a lab-
oratory artifact, for example due to unattrac-
tive sites for web construction. However, the
long latency did not interfere with the rearing
regime. The animals appeared to be well
adapted to temporary starvation because the
mortality was low in this phase (Fig. 6). Also
in the field, the spiderlings do not immediately
start with prey-capture web construction (Foll-
ner & Klarenberg 1995) and endure extended
periods of starvation. Argiope spiderlings eas-
ily survive several days nearby their cocoons,
sometimes with communal meshworks of in-
terlocking dragline threads (‘‘communal tan-
gles’’) (Tolbert 1976, 1977; Follner & Klar-
enberg 1995) where they find shelter until
favorable weather or microclimate conditions
allow for ballooning (Tolbert 1977; Follner &
Klarenberg 1995; see also Suter 1999 for
physics of ballooning).
Argiope spiderlings actively select suitable
web sites by ballooning, re-ballooning or
walking (Enders 1973; Tolbert 1977; Follner
& Klarenberg 1995). Also in this nonpreda-
tory phase the spiderlings must avoid starva-
tion. Tolbert (1976) kept A. aurantia spider-
lings in the laboratory without food and water.
Mortality remained moderate in these experi-
ments for several days and only increased dis-
tinctly about two weeks after hatching.
The behavioral ballooning sequence could
be easily triggered under artificial conditions
in our study, suggesting that it will also occur
in the field whenever environmental condi-
tions allow. Therefore dispersal and popula-
tion structure will be primarily driven by mi-
croclimatic conditions in the local habitats.
The local persistence of non-emigrants (non-
ballooners and short-distance ballooners) in A.
bruennichi populations might facilitate aggre-
gated dispersion patterns, just as in weather
phases which are unfavorable for aerial dis-
persal. Given ballooning is a less effective
means of long distance dispersal than previ-
ously thought (Roff 1981; Decae 1987; Wise
1993; Bonte et al. 2003), this could also ex-
plain the genetic differentiation among habitat
patches in other Argiope species (Ramirez &
Haakonsen 1999).
The role of natural selection in range ex-
pansion has recently been discussed for in-
sects in the context of global warming (e.g.,
Pimm 2001; Thomas et al. 2001). However,
improving environmental conditions at range
margins can initiate range extensions purely
on the basis of ecological, physiological and
population-dynamic processes not requiring
any evolutionary change (Thomas et al. 2001;
see also Coope 1995; Williamson 1996). Our
results are in line with these views and reject
the hypothesis of Follner & Klarenberg (1995)
that evolutionary processes have changed bal-
looning behavior in newly founded popula-
We are grateful to Peter Neumann, Gail E.
Stratton and two anonymous reviewers for
helpful comments on previous drafts of the
manuscript. We thank Christian W.W. Pirk for
statistical advice, Vlastimil Ru´zˇicka and Theo
Blick for providing literature. This study was
supported by a research fellowship to A.W.
from the State of Saxony-Anhalt and by the
Deutsche Forschungsgemeinschaft (DFG)
grant to P.B. (BL 776/1-1).
Arnold, A. 1986. Die Wespenspinne Argyope
bruennichi (Scopoli) im Stadtgebiet von Leipzig
(Arachnida, Araneae). Entomologische Nachri-
chten und Berichte 30:268–269.
Bonte, D., N. Vandenbroecke, L.Lens & J.-P. Mael-
fait. 2003. Low propensity for aerial dispersal in
specialist spiders from fragmented landscapes.
Proceedings of the Royal Society of London (B)
Bristowe, W.S. 1939. The Comity of Spiders. Vol.
I. Ray Society, London.
Coope, G.R. 1995. Insect faunas in ice age envi-
ronments: why so little extinction? Pp. 55–74. In
Extinction Rates (J.H. Lawton & R.M. May,
eds.). Oxford University Press, Oxford.
Coyle, F.A. 1983. Aerial dispersal by mygalomorph
spiderlings (Araneae, Mygalomorphae). Journal
of Arachnology 11:283–286.
Crome, W. & I. Crome. 1961. Paarung und Eiablage
bei Argyope bruennichi (Scopoli) auf Grund von
Freilandbeobachtungen an zwei Populationen im
Spreewald/Mark Brandenburg (Araneae: Aranei-
dae). Mitteilungen aus dem Zoologischen Mu-
seum in Berlin 37:189–252.
Dean, D.A. & W.L. Sterling. 1985. Size and phe-
nology of ballooning spiders at two locations in
eastern Texas. Journal of Arachnology 13:111–
Decae, A.E. 1987. Dispersal: ballooning and other
mechanisms. Pp. 348–356. In Ecophysiology of
Spiders (W. Nentwig, ed.). Springer–Verlag, Ber-
lin Heidelberg New York.
Eberhard, W.G. 1987. How spiders initiate airborne
lines. Journal of Arachnology 15:1–9.
Enders, F. 1973. Selection of habitat by the spider
Argiope aurantia Lucas (Araneidae). American
Midland Naturalist 90:47–55.
Follner, K. 1994. Ballooning und Mikrometeorolo-
gie bei Argiope bruennichi (Scopoli, 1772) (Ar-
aneae, Argiopidae). Diploma Thesis, Ludwig-
Maximilians-Universita¨t Mu¨nchen, 76 pp.
Follner, K. & A. Klarenberg. 1995. Aeronautic be-
haviour in the wasp-like spider, Argiope bruen-
nichi (Scopoli) (Araneae, Argiopidae). Pp. 66–
72. In Proceedings of the 15
Colloquium of Arachnology, C
ˇeske´ Budeˇjovice
1994 (V. Ru´zˇicˇka, ed.). Czech Academy of Sci-
ences, Institute of Entomology, C
ˇeske´ Budeˇjo-
Gauckler, K. 1968. Argyope bruennichi, die scho¨ne
Wespenspinne, durchwandert Franken, erreicht
die Oberpfalz und das Bayerische Alpenvorland.
Mitteilungen der Naturhistorischen Gesellschaft
Nu¨rnberg 2:1–5.
Gillandt, L. & J.M. Martens. 1980. Verbreitung und
Biotopbindung der Wespenspinne Argiope
bruennichi im Landkreis Lu¨chow-Dannenberg
(Arach.: Araneae). Verhandlungen des naturwis-
senschaftlichen Vereins Hamburg (NF) 23:309–
Guttmann, R. 1979. Zur Arealentwicklung und
¨kologie der Wespenspinne (Argiope bruenni-
chi) in der Bundesrepublik Deutschland und den
angrenzenden La¨ndern. Bonner zoologische Bei-
tra¨ge 30:454–486.
Helsdingen, P. J. van. 1982. Postglacialeuitbreiding
van Argiope bruennichi Scop. nu ook tot in Ned-
erland. De Levende Natuur 84:121–123.
Jonsson, L.J. & P. Wilander. 1999. A
¨r getingspin-
deln, Argiope bruennichi, etablerad i Sverige?
Entomologisk Tidskrift 120:17–21.
Ko¨hler, G. & G. Scha¨ller. 1987. Untersuchungen
zur Pha¨nologie und Dormanz der Wespenspinne
Argiope bruennichi (Scopoli) (Araneae: Aranei-
dae). Zoologisches Jahrbuch fu¨r Systematik 114:
Levi, H.W. 1983. The orb-weaver genera Argiope,
Gea, and Neogea from the Western Pacific re-
gion (Araneae: Araneidae, Argiopinae). Bulletin
of the Museum of Comparative Zoology 150:
Lohmeyer, W. & P. Pretscher. 1979. U
¨ber das Zus-
tandekommen halbruderaler Wildstauden-Queck-
en-Fluren auf Brachland in Bonn und ihre Be-
deutung als Lebensraum fu¨r die Wespenspinne.
Natur und Landschaft 54:253–259.
Malt, S. 1996. Untersuchungen zur Rolle ausge-
wa¨hlter netzbauender Spinnen (Araneida) im tro-
phischen Beziehungsgefu¨ge von Halbtrockenra-
sen. Dissertation, Friedrich-Schiller-Universita¨t
Jena, 134 pp.
Mu¨ller, M.C. & W. Westheide. 1993. Comparative
morphology of the sexually dimorphic orb-weav-
ing spider Argiope bruennichi (Araneae: Aranei-
dae). Proceedings of the XII International Con-
gress of Arachnology, Brisbane 1992. Memoirs
of the Queensland Museum 33:615–620.
Nielsen, E. 1932. The Biology of Spiders. With es-
pecial Reference to the Danish Fauna. Vol. I &
II, Levin & Munksgaard, Copenhagen.
Nyffeler, M. & G. Benz. 1987. Thefoliage-dwelling
spider community of an abandoned grassland
ecosystem in eastern Switzerland assessed by
sweep sampling. Mitteilungen der Schweizer-
ischen Entomologischen Gesellschaft 60:383–
Pasquet, A. 1984. Predatory-site selection and ad-
aptation of the trap in four species of orb-weav-
ing spiders. Biology of Behaviour 9:3–19.
Pimm, S.L. 2001. Entrepreneurial insects. Nature
Puts, C. 1988. LArgiope fascie´e en Belgique: ra-
dioscopie d’une conqueˆte. Bulletin des Reserves
Naturelle et Ornithologiques de Belgique 4:116–
Ramirez, M.G. & K.E. Haakonsen. 1999. Gene flow
among habitat patches on a fragmented land-
scape in the spider Argiope trifasciata (Araneae:
Araneidae). Heredity 83:580–585.
Richter, C.J.J. 1970. Aerial dispersal in relation to
habitat in eight wolf spider species (Pardosa,Ar-
aneae, Lycosidae). Oecologia 5:200–214.
Roff, D.A. 1981. Dispersal in dipterans: its costs
and consequences. Journal of Animal Ecology
Sacher, P. & P. Bliss. 1989. Zum Vorkommen der
Wespenspinne (Argiope bruennichi) im Bezirk
Halle (Arachnida: Araneae). Hercynia (NF) 26:
Sacher, P. & P. Bliss. 1990. Ausbreitung und Bes-
tandssituation der Wespenspinne (Argiope bruen-
nichi) in der DDR—ein Aufruf zur Mitarbeit.
Entomologische Nachrichten und Berichte 34:
Scharff, N. & S. Langemark. 1997. Hvepseedder-
koppen Argiope bruennichi (Scopoli) i Danmark
(Araneae; Araneidae). Entomologiske Meddelel-
ser 65:179–182.
Smithers, P. 2000. Argiope bruennichi (Scopoli,
1772): a review of recent British records. Newslet-
ter of the British arachnological Society 87:2–3.
Suter, R.B. 1999. An aerial lottery: the physics of
ballooning in a chaotic atmosphere. Journal of
Arachnology 27:281–291.
Thomas, C.D., E.J. Bodsworth, R.J. Wilson, A.D.
Simmons, Z.G. Davies, M. Musche & L. Con-
radt. 2001. Ecological and evolutionary process-
es at expanding range margins. Nature 411:577–
Tolbert, W.W. 1976. Population dynamics of the orb
weaving spiders Argiope trifasciata and Argiope
aurantia (Araneae, Araneidae): density changes
associated with mortality, natality and migra-
tions. Ph.D. Thesis, University of Tennessee,
Knoxville, 172 pp.
Tolbert, W.W. 1977. Aerial dispersal behavior of
two orb weaving spiders. Psyche 84:13–27.
Weyman, G.S. 1993. A review of the possible caus-
ative factors and significance of ballooning in
spiders. Ethology Ecology & Evolution 5:279–
Wiehle, H. 1931. Araneidae. Pp. 1–136. In Die
Tierwelt Deutschlands und der angrenzenden
Meeresteile, 23. Teil. Spinnentiere oder Arach-
noidea, VI. Agelenidae—Araneidae (F. Dahl,
ed.). Gustav Fischer Verlag, Jena.
Williamson, M. 1996. Biological Invasions. Chap-
man & Hall, London.
Wise, D.H. 1993. Spiders in Ecological Webs. In
Cambridge studies in ecology (H.J.B. Birks &
J.A. Wiens, eds.). Cambridge University Press,
328 pp.
Manuscript received 17 September 2004, revised 10
August 2005.
... The Argiope species have a high dispersive capacity through their ballooning capabilities (Ramírez & Haakonsen 1999;Walter et al. 2005). Likely, this behavior is responsible for the relatively fast poleward range expansion of A. bruennichi that has been observed in recent decades (Walter et al. 2005). ...
... The Argiope species have a high dispersive capacity through their ballooning capabilities (Ramírez & Haakonsen 1999;Walter et al. 2005). Likely, this behavior is responsible for the relatively fast poleward range expansion of A. bruennichi that has been observed in recent decades (Walter et al. 2005). Kumschick et al. (2011) suggested that the northern range limit is expanding either because A. bruennichi is not in equilibrium with its climatic niche (i.e., the species contracted its range due to past climatic events and has not yet been able to re-colonize all suitable locations) or because it has developed cold tolerance. ...
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The ecological niches of the three Iberian Argiope species have not been studied in quantitative detail, and recently developed approaches for assessing niche overlap have rarely been applied to invertebrates. This study aimed to quantify the climatic niche differences between Argiope bruennichi (Scopoli, 1772), A. lobata (Pallas, 1772) and A. trifasciata (Forsskål, 1775) in the Iberian Peninsula. An extensive occurrence database for the three species was compiled from the literature, a citizen science project (Biodiversidad Virtual) and a social network (Flickr). Niche comparison and recursive partitioning analyses were used to compare and characterize the niches of these species using regional climatic information. The three Argiope species had different distribution patterns within the Iberian Peninsula with a clear degree of sympatry. Despite an appreciable niche overlap, the three species had significantly different climatic niches. A. bruennichi was present in colder and more humid environments, while A. lobata and A. trifasciata selected warmer, drier environments. A. trifasciata preferred areas with higher minimum temperatures than A. lobata and avoided continental environments that the two other species tolerated. Despite these differences, the Iberian Peninsula contained a broad range of suitable environments where more than one species co-occurred. Further studies are needed to explore these species relationships, particularly given the trend of ranges shifting north due to global warming. Considering both the results of this study and the increasingly xeric conditions in the Iberian Peninsula, A. lobata and A. trifasciata may benefit at the expense of a retraction of A. bruennichi.
... Postembryos moult once to first instar spiderlings in the egg sac and emerge from it during the following spring [49]. Ballooning behaviour, if it occurs, is restricted to the juvenile stages of this species [51,53]. After several moults the spiders reach maturity in summer. ...
... Rappelling spiderlings become airborne by releasing ballooning threads and biting through the safety thread. Since tip-toe behaviour was rare (1.7 %) in agreement with other work on A. bruennichi [51,53], we pooled both behaviours, which are henceforth referred to as ballooning behaviour. Those spiderlings that ballooned were caught in their airborne phase with a sweep net. ...
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Background: Dispersal and reproduction are key life-history traits that jointly determine species' potential to expand their distribution, for instance in light of ongoing climate change. These life-history traits are known to be under selection by changing local environmental conditions, but they may also evolve by spatial sorting. While local natural selection and spatial sorting are mainly studied in model organisms, we do not know the degree to which these processes are relevant in the wild, despite their importance to a comprehensive understanding of species' resistance and tolerance to climate change. Methods: The wasp spider Argiope bruennichi has undergone a natural range expansion - from the Mediterranean to Northern Europe during the recent decades. Using reciprocal common garden experiments in the laboratory, we studied differences in crucial traits between replicated core (Southern France) and edge (Baltic States) populations. We tested theoretical predictions of enhanced dispersal (ballooning behaviour) and reproductive performance (fecundity and winter survival) at the expansion front due to spatial sorting and local environmental conditions. Results: Dispersal rates were not consistently higher at the northern expansion front, but were impacted by the overwintering climatic conditions experienced, such that dispersal was higher when spiderlings had experienced winter conditions as occur in their region. Hatching success and winter survival were lower at the range border. In agreement with theoretical predictions, spiders from the northern leading edge invested more in reproduction for their given body size. Conclusions: We found no evidence for spatial sorting leading to higher dispersal in northern range edge populations of A. bruennichi. However, reproductive investment and overwintering survival between core and edge populations differed. These life-history traits that directly affect species' expansion rates seem to have diverged during the recent range expansion of A. bruennichi. We discuss the observed changes with respect to the species' natural history and the ecological drivers associated with range expansion to northern latitudes.
... Being typical web-building spiders, A. bruennichi spiderlings disperse by ballooning, with the attendant high risk of ending up in unsuitable habitat. However, there is no consensus as to whether ballooning is obligate after hatching out of the egg sac (Follner and Klarenberg, 1995) or not (Walter et al., 2005). Intuitively, some hatchlings should be short-distance dispersers that remain at their natal site of known quality (Walter et al., 2005). ...
... However, there is no consensus as to whether ballooning is obligate after hatching out of the egg sac (Follner and Klarenberg, 1995) or not (Walter et al., 2005). Intuitively, some hatchlings should be short-distance dispersers that remain at their natal site of known quality (Walter et al., 2005). Since spiderlings hatch out of the egg sac simultaneously (which in A. bruennichi is several hundred individuals), short-distance dispersers would create a population substructure with patches of closely related individuals. ...
Background: One may expect inbreeding avoidance via mate choice to evolve if two circumstances arise: The risk of inbreeding is high but avoidable, and there is sufficiently severe inbreeding depression. Organism: The European wasp spider (Argiope bruennichi) in which males are monogynous or conditionally bigynous and polyandrous females cannibalize up to 80% of their mates following copulation. Goal: Assess the potential for inbreeding and inbreeding avoidance by determining the fine-scale spatial genetic structure of natural spider populations. Investigate pre-copulatory inbreeding avoidance mechanisms. Methods: Search for patterns of fine-scale spatial genetic structure across three populations using 16 polymorphic microsatellite loci before and after mate search. Sample twice. In the first, estimate genetic distances of sub-adult males and juvenile females using spatial autocorrelation analysis. In the second, determine genetic distances of guarding males and guarded females. In addition, monitor mate acceptance and rejection in the field, genetically screen the mating partners, and assess the genetic distance between the male and female. Results: We found no fine-scale genetic substructure and no evidence for clusters of related juveniles. The probability of encountering genetically similar mates following male mate search was around 10% on average and differed between populations. Furthermore, the data revealed no correlation between genetic similarity and male rejection against virgin females.
... Pre-copulatory courtship of male A. bruennichi involves close contact between males and females [46], facilitating the mutual assessment of chemical profiles. While genetic diversity is usually high in natural populations of the species, probably owing to effective long-distance dispersal of spiderlings [23,47], a proportion of spiderlings often remains near the egg-sac [48]. Thus, both sexes would potentially benefit from discriminating kin upon mating. ...
Kin recognition, the ability to detect relatives, is important for cooperation, altruism and also inbreeding avoidance. A large body of research on kin recognition mechanisms exists for vertebrates and insects, while little is known for other arthropod taxa. In spiders, nepotism has been reported in social and solitary species. However, there are very few examples of kin discrimination in a mating context, one coming from the orb-weaver Argiope bruennichi . Owing to effective mating plugs and high rates of sexual cannibalism, both sexes of A. bruennichi are limited to a maximum of two copulations. Males surviving their first copulation can either re-mate with the current female (monopolizing paternity) or leave and search for another. Mating experiments have shown that males readily mate with sisters but are more likely to leave after one short copulation as compared with unrelated females, allowing them to search for another mate. Here, we ask whether the observed behaviour is based on chemical cues. We detected family-specific cuticular profiles that qualify as kin recognition cues. Moreover, correlations in the relative amounts of some of the detected substances between sexes within families indicate that kin recognition is likely based on subsets of cuticular substances, rather than entire profiles.
... Spiders inhabiting unstable and open environments exhibit large dispersive capacities by air (Meijer 1977). In the case of A. bruennichi, ballooning is not obligatory (Walter et al. 2005), and many years of research carried out in Switzerland confirm the poor movement of A. bruennichi by air (Blandenier 2009). Another important factor affecting the effectiveness of expansion is the diversity and structure of zoocenosis where a new species appears. ...
Expanding range is an inherent feature of any species and may be caused by climate change, destruction or other change of habitat, or lack of natural enemies. In a new habitat the species may be neutral, or as predator it can displace related species through competition. A strong expansion to northern Europe was observed in the thermophilous spider species Argiope bruennichi. The species doubled its range in Poland during the 1990s and its impact on native species was not investigated so far. In this article, the results of studies about A. bruennichi number (density) and its contribution in orb-weaver spider communities are analysed. We also try to determine the impact of newly occurring species on the local araneofauna.
... Opinion as to whether ballooning is an obligatory life history phase has also remained polarised [39,123,127], with certain reports indicating it as non-essential for certain species [128]. This brings into question the use of ballooning in the five spider species we investigated. ...
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Gene flow and genetic variation were examined within and among populations of five of the most common spider species in shrublands of the mountainous Golden Gate Highlands National Park (GGHNP), South Africa. These species included three active hunters, Dendryphantes purcelli Peckham & Peckham, 1903 (Salticidae), Pherecydes tuberculatus O.P.-Cambridge, 1883 (Thomisidae) and Philodromus browningi Lawrence, 1952 (Philodromidae), and two web-builders, Neoscona subfusca (C.L. Koch, 1837) (Araneidae) and a Theridion Walckenaer, 1802 species (Theridiidae). A total of 249 spiders (57 D. purcelli, 69 N. subfusca, 34 P. browningi, 56 P. tuberculatus and 33 Theridion sp.) were collected and analysed from six shrubland localities in the park. Analyses of sequence variation of the mitochondrial cytochrome oxidase c subunit I (COI) gene for each species revealed relatively low nucleotide diversity (π < 0.0420) but high genetic diversity (Hd > 0.6500) within populations for all species, except P. tuberculatus. Genetic differentiation was also noted to differ between species, with only P. tuberculatus indicating very large divergence (Fst > 0.2500). These results were reflected by gene flow, with D. purcelli, N. subfusca and the Theridion sp. estimated as experiencing more than one disperser per generation. Overall, highest gene flow was found in the two web-building species, indicating possible high dispersal ability of these spiders in the GGHNP. Additionally, constructed phylogenies indicated possible cryptic speciation occurring in the majority of the investigated species. Our current results indicate that the five investigated spider species were able to maintain gene flow between shrubland populations within the GGHNP to some degree, despite the mountainous landscape. However, further analyses incorporating additional molecular markers are needed to properly determine the extent of genetic diversity and gene flow of these species within the GGHNP.
... Many spider species disperse as juveniles by ballooning, where immature individuals take off by spinning long threads of silk, allowing them to be blown around on the air currents. The ballooning behaviour of Wasp spiders Argiope bruennichi [74], combined with favourable atmospheric events (no rain, the wind blowing from the right direction, and the presence of vertical upwards air movements) during the species' dispersal period may well have been instrumental in the arrival of this species from continental Europe to the UK in the 1990s. We suggest that the exhibition of traits associated with greater dispersal potential via atmospheric events, such as ballooning behaviours or the production of macropterous forms (e.g., for the orthopteran Metrioptera roeselii [75,76], together with frequent atmospheric events facilitating long-distance dispersal, is likely to be particularly important for saltatorial population expansion across waterbodies or other large-scale barriers to spread. ...
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Species introduced outside their natural range threaten global biodiversity and despite greater awareness of invasive species risks at ports and airports, control measures in place only concern anthropogenic routes of dispersal. Here, we use the Harlequin ladybird, Harmonia axyridis, an invasive species which first established in the UK from continental Europe in 2004, to test whether records from 2004 and 2005 were associated with atmospheric events. We used the atmospheric- chemistry transport model SILAM to model the movement of this species from known distributions in continental Europe and tested whether the predicted atmospheric events were associated with the frequency of ladybird records in the UK. We show that the distribution of this species in the early years of its arrival does not provide substantial evidence for a purely anthropogenic introduction and show instead that atmospheric events can better explain this arrival event. Our results suggest that air flows which may assist dispersal over the English Channel are relatively frequent; ranging from once a week from Belgium and the Netherlands to 1–2 times a week from France over our study period. Given the frequency of these events, we demonstrate that atmospheric-assisted dispersal is a viable route for flying species to cross natural barriers.
... In addition to the field examinations, I investigated 22 A. bruennichi females in the lab. Spiders were lab raised from their emergence from the egg sac according to Walter et al. (2005). For the observation, the adult spiders were kept in wooden web frames (35 3 35 3 7cm) individually. ...
Silk decorations in webs of orb-weaving spiders are considered visual signals. However, high pattern variation reduces the plausibility of a single signal function, and accordingly, current literature often presents contradicting explanations. The controversial question is whether specific web decoration shapes also serve specific functions or whether various arrangements can serve a single function. I studied inherent characteristics of the variation of silk decoration shapes in Argiope bruennichi (Scopoli, 1772), in the field and under invariant laboratory conditions. The results show, that even within a few days and with a small repertoire of patterns, A. bruennichi frequently varies the decoration shape. Field and laboratory data both reveal that this variation follows a predictable pattern, significantly differing from random. Spiders show a preference for two-banded decorations, omitting decorating altogether rather than building one-banded decorations. Since the shape matters to the spiders, this supports the idea of a single signal function in spite of the presence of web decoration pattern variability.
... Spiders can travel passively with the wind from a few metres to hundreds of kilometres (Bonte, Baert, Lens, & Maelfait, 2004;Follner & Klarenberg, 1995). Ballooning is thought to be the main mechanism of habitat colonization by spiders (Weyman & Jepson, 1994), however, this phenomenon is presumed to occur mainly during juvenile stages (Walter, Bliss, & Moritz, 2005). Nevertheless, its role in maintaining a proper genetic cohesion between orb web spider populations is significant (Kuntner et al., 2014;Lee, Jiang, Su, & Tso, 2004). ...
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We examined morphological and genetic variation within and among populations of the spider Argiope trifasciata (Forsskål, 1775) in Tunisia. One hundred and twenty-five spiders were collected from 13 localities spread over three climatic subdivisions. Analyses of sequence variation in a 631bp segment of the mitochondrial cytochrome oxidase c subunit I (cox1) gene revealed low nucleotide diversity but high genetic diversity within populations (Hd = 0.729). A noticeable genetic differentiation was found in all populations. However, no genetic differentiation was observed within climatic subdivisions. Sixteen haplotypes were identified. Connectivity between populations, except for the Gabes population, was relatively high, which could be explained by the high dispersal ability of these spiders by passive aerial movement through the wind (ballooning). Our results indicate that gene flow between Gabes and the remaining regions was limited. In corroboration with the genetic data, morphological analyses did not show differentiation among populations or according to climatic subdivisions. Demographic stability of A. trifasciata populations mediated by gene flow was observed. Moreover, a homogeneous phenotypic trend was observed within A. trifasciata populations across Tunisia. This finding could be explained by the high conservation of external morphological characters within the spider lineages, which are therefore not affected by environmental factors.
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Rearing of animals from one generation to the next is important in many biological studies. In this study, we aimed to develop efficient methods for rearing multiple generations of orb-web spiders (Cyclosa argenteoalba), testing three methods. First, we examined isolated rearing with aphid supplied by hand. Second, we tested mass rearing. We also collected various insect species from the field using light trap and supplied them by hand. Both methods failed, perhaps because of the inappropriate aphid (Uroleucon formosanum) and insufficient quantity of prey supplied in the first and second tests, respectively. For the third method, we mass reared with abundant prey directly supplied from light traps into the terrariums located outside. This method successfully raised hatchlings to adults, and the eggs produced from these adults also matured. The development time of wintering and non-wintering cohorts was 150.2-195.0 days and 24.0-76.3 days, respectively.
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In den vergangenen Jahrzehnten breitete sich Argiope bruennichi in Mitteleuropa rasch aus. Die große Geschwindigkeit, mit der die Ausbreitung stattfand, ließ eine Untersuchung des unter Spinnen verbreiteten Ballooning, des Luftfahrens am eigenen Faden, an Argiope bruennichi interessant erscheinen. Über diesen Ausbreitungsmodus ist wenig bekannt, entsprechend ist seine Bedeutung für die Besiedelung instabiler Habitate und Agrarflächen umstritten. Untersucht wurde in der vorliegenden Diplomarbeit, welcher Anteil der Jungspinnen zur Luftfahrt startet, wie sie sich zwischen Kokonschlupf und Ballooning verhalten und wie Schlupf und Ballooning durch die mikroklimatischen Faktoren Temperatur und Windgeschwindigkeit beeinflußt werden. Sowohl im Freiland als auch in Gefangenschaft konnte beobachtet werden, daß Jungspinnen von Argiope bruennichi keine Radnetze bauen, bevor sie eine Luftfahrt absolviert haben. Ballooning ist also ein obligater Abschnitt im Lebenszyklus nach dem Überwintern im Kokon und vor dem Bau des ersten Radnetzes. Die Spinnen werden durch negative Geotaxis und positive Phototaxis zu einem geeigneten Startplatz für die Luftfahrt geleitet. Um die meteorologischen Daten zu erfassen standen ein Anemometer für die Windgeschwindigkeit, 6 Thermofühler für die Temperaturschichtung der unteren 2m über dem Boden und 26 Temperaturfühler für die Kokontemperaturen zur Verfügung. Diese Wetterwerte wurden selbständig im Freiland aufgezeichnet. Die in 20 - Minuten - Intervallen gezählten schlüpfenden und abfliegenden Jungspinnen können Wettersituationen erkennen, in denen Thermik entsteht und Ballooning möglich ist. Zwei wichtige Auslöser für das Verlassen des Kokons und das Ballooning sind die Temperatur im Kokon und steigende Temperaturen beim Hochklettern in der Vegetation. Diese steigenden Temperaturen sind ein Spiegelbild der labilen Temperaturschichtung oberhalb der Vegetation, die thermische Turbulenz verursacht. Da die beiden auslösenden Faktoren für Schlupf und Ballooning genauso wie Thermik die Folge von Sonneneinstrahlung sind, haben sie für die Jungspinnen hohen Wert als Anzeiger für Wettersituationen, die für Luftfahrt geeignet erscheinen.
The meaning of the word dispersal both in a general and in a biological context, is somewhat equivocal. Confusion originates from the fact that dispersal may indicate either the event of being dispersed or the act of dispersing (Longman 1978). In order to obtain useful definitions for various migrational processes, Pielou (1979) distinguished three kinds of dispersal. Her two classes of diffusion and secular migration, both concerned with slow and gradual shifts in the distribution range of a species, are not relevant here. Only the events falling into her classification of jump-dispersal are relevant to the type of dispersal considered here. Quoting Pielou’s definition: “Jump-dispersal is the movement of individual organisms across great distances, followed by successful establishment of a population of the original dispersers’ descendants at the destination. The salient points are that the whole journey is completed in a short period of time, usually very much shorter than the life-span of an individual; and that the journey usually takes the dispersers across totally inhospitable terrain as, for example, when spiders are carried by air currents far across the open sea.” As interpreted here, dispersal does not necessarily involve an extension of the original distribution range of a species. This is in contrast to Platnick’s (1976b) view, in which the use of the term dispersal is specifically restricted to indicate events of range extension.
Visual search for the webs and egg sacs of Argiope aurantia Lucas showed that it is most abundant in dense perennial vegetation. This pattern of distribution was confirmed by release of the species in selected plant communities: more spiders remained in densely vegetated sites than in sparsely vegetated ones, both in the 2nd instar and in middle immature instars; but adults and subadults left densely vegetated wood-lands to build webs at the edge of those woods. It is suggested that wind reduction is the significant stimulus to immatures, and light, to adults.
(1) This paper examines the reproductive cost of dispersal in dipterans. D. melanogaster is used as a representative dipteran. (2) Flight significantly reduces egg production and both the duration of flight and the size of the female are important parameters in this relationship. (3) Evidence is presented which suggests that activity is positively correlated with size, the probability of dispersal from a site increasing with body size. (4) The probability of dispersal of females increases with temperatures although the reproductive cost of dispersal also increases. The dispersal rate of male flies is not correlated with temperature. (5) The dynamics of colonization are discussed in the light of these findings.
The banded garden spider (Argiope trifasciata) is a common orb weaver of old field habitats in the United States. In this study, we determined levels of genetic variability and gene flow among seven populations in central Pennsylvania, based on variation at eight allozyme loci. Mean heterozygosity (observed) per population was 7.5% and mean polymorphism was 39.3%, consistent with levels of variability in other arthropods. Values of GST for the four polymorphic loci (mean GST=0.011) suggest that gene flow prevents the genetic differentiation of these populations. The average number of migrants per generation (Nm) among these populations is estimated to be 31.3. The lack of significant interpopulation genetic differentiation among these disjunct populations may result from spiderling aerial dispersal (ballooning), a more continuous distribution of suitable habitat in the past, and perhaps the use of roadside vegetation as gene flow corridors. On the other hand, the study populations did not exhibit isolation-by-distance, suggesting that suitable habitat in our study area is experienced as less than continuous by A. trifasciata. Thus, although A. trifasciata is an excellent ballooner, ballooning does not confer unlimited access among all populations, which suggests that ballooning may be a far less effective means of long-distance dispersal than previously thought.