1. The function of ventral body coloration of the ladder web spider
Herennia multipuncta Department of Life Science, Tunghai University, Taiwan
Hsien-Chun Liao
Body color as predator intimidation signal?Body color as predator intimidation signal?
Herennia exhibiting conspicous colorationHerennia exhibiting conspicous coloration
An orb spider inhabitaing tree trunksAn orb spider inhabitaing tree trunks Testing visual lure function by Herennia dummiesTesting visual lure function by Herennia dummiesDD
EE Testing anti-predator founction of ventrum colorationTesting anti-predator founction of ventrum coloration
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Could body coloration of
Herennia also function as a
visual lure?
»» Herennia spiders usually build highly elongated webs that are as much as
seven times taller than wide and are attached against tree trunks.
»» Such web-building behavior allows spiders to maximize web area and
foraging intake when they are forced to build webs in space-limited
microhabitats. (Kuntner, 2008)
»» Neoscona spider's bright coloration
also functioned as visual lure
during the night.
(Chuang et al. 2008; Blamires et al. 2012)
»» Giant wood spiders with typical
coloration had higher prey
interception than melanic ones.
(Tso et al. 2002, 2004)
»» Herennia spiders place the ladder web against the tree trunk with cryptic
dorsum exposed and conspicuous ventrum concealed.
»» The field experiment was conducted
in July, 2012, in a subtropical forest in
Nantou county, Taiwan.
»» The dummies of Herennia spiders
were constructed and monitored
during 8:00~12:00 and 20:00~24:00.
»» Previous studies showed that the prominent body coloration of orb-
weaving spider could visually lure prey:
»» Preliminary data showed that
various body colors of Herennia
spider were conspicuous when
seen against the tree trunk .
»» The dummies were divided into four different categories, and the
reflectance spectra were similar to those of real spiders.
»» The color contrasts were calculated by visual neuroethological models
developed for diurnal and nocturnal insects.
»» In enclosures the interactions between lizard and spider were recorded
by digital video camera. Each monitoring lasted 4 hours.
»» Preliminary data showed that 12 Herennia spiders were consumed, and 3
of them performed push-up when lizard approached.
»» The video data are still under analysis. I hypothesize that spiders in
control group will have better predator intimidation performence.
We found that when lizards approached
Herennia, the spider would perform push-
up movements. Does the ventral bright
coloration of Herennia function to defend
the spider by predator intimidation?
Some organisms with eyespots survive by
predator intimidation.
»» The chromatic color contrast of orange and gray part of dummies were
similar to those of Herennia spiders.
»» The data is still under analysis, I hypothesize that orange and gray body
parts may function as visual lures.
10
0
20
30
40
50
60
70
Wavelength (nm)
300 400 500 600 700
Relativequantumcatch(%)
Herennia muntipuncta
Dummy spider
Control group Orange group
Gray group None group
chromatic
achromatic
0
0.3
0.2
0.1
-0.1
-0.2
-0.3
-0.4
-0.5
-0.6
Colorcoontrast
0.05
0
0.1
0.15
0.2
0.25
Chromaticcolorcontrast
Honey Bee
Hawk Moth
Gray Black Orange
Control group
Experimental group
0%
25%
50%
75%
100%
Control group Experimental group
Consumed Survived
N = 25 N = 24
PUSH UP!?
100％
50％
0％
Experimental group Control group
Sruvivalofbutterflies(%)
p < 0.01
Previous studies This study
Photo by Terago
Photo by Gidzy
(Vallin et al., 2005)
Inachis io
Japalura
swinhonis
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0
chromatic
achromatic
Colorcoontrast
