Figure 1.
Spiders and inflorescences used in Experiment 1.
(A) A white female Thomisus spectabilis crab spiders sitting on a white flower, (B) a yellow female Thomisus spectabilis crab spiders sitting on a yellow inflorescence and (C) a Bidens alba patch.
Figure 2.
Blue painted spiders used in Experiment 2.
(A) a Thomisus spectabilis female with the forelimbs painted on blue and (B) a Thomisus spectabilis female with the dorsal part of the abdomen painted on blue.
Figure 3.
Reflectance spectra of inflorescences and spiders (Experiment 1).
Reflectance spectra of (A) yellow (green circles N = 36) and white (white circles N = 34) Thomisus spectabilis females, (B) white outer florets (white triangles N = 34) and yellow inner florets (green triangles N = 36) of Bidens alba inflorescences. Error bars in panel (A) and (B) represent standard deviations. Panel C illustrates the colour loci of all spiders and inflorescences in the colour hexagon of honeybees calculated for white spiders (white circles N = 34), white outer florets (white triangles N = 34), yellow spiders (green circles N = 36) and yellow inner florets (green triangles N = 36).
Figure 4.
Effect of spider UV and spider size on honeybee behaviour (Experiment 1).
Proportion of honeybee visits to spider inflorescences vs spider UV reflectance considering only those trials that received more than four honeybee visits to the patch. Trials with less than five visits were removed because the statistical model gives relatively little weight to trials with few honeybee visits. Black symbols represent small spiders (prosoma width <3.44 mm) and white symbols represent large spiders (prosoma width >3.44 mm). The value of 3.44 mm represents the median value of spider prosoma's width for trials that received more than four honeybee visits to the patch. Triangles represent yellow spiders and circles represent white spiders. Regression lines between proportion of honeybee visits to spider inflorescences and spider UV reflectance for small (solid line) and large (dashed line) spiders are given in the figure, together with the expected proportion of visits to spider inflorescences if honeybees treated all inflorescences alike (p = 1/3; dotted line).
Figure 5.
Effect of spider colour and size on spider hunting success (Experiment 1).
Spider hunting success vs spider size for white spiders (white circles) and yellow spiders (black triangles). Lines represent fitted values of capture probability for white (solid line) and yellow (dashed line) spiders.
Figure 6.
Colour loci of blue-painted spiders in the colour hexagon of honeybees (Experiment 2).
Colour loci in the colour hexagon of honeybees calculated for blue-painted spiders (blue circles N = 37), white outer florets (white triangles N = 37) and yellow inner florets (yellow triangles N = 37).
Figure 7.
Effect of spider size on honeybee behaviour (Experiment 2).
Proportion of honeybee visits to spider inflorescences vs spider size (A) considering all the trials conducted in the experiment and (B) considering only those trials that received more than six honeybee visits to the patch. Black circles represent spiders with the dorsal part of the abdomen painted on blue, grey triangles represent spiders with the forelimbs painted on blue and white circles represent control spiders. Solid lines represent fitted probability of landing on spider harbouring inflorescences. Although the relationship between probability of landing on spider inflorescences and spider size is not apparent in panel (A), the statistical model gives relatively little weight to trials with few honeybee visits removed to produce (B). Dotted lines represent the expected value if honeybees treated all inflorescences alike (p = 1/3).
Figure 8.
Effect of spider size on spider hunting success (Experiment 2).
Spider hunting success vs spider size for spiders with the dorsal part of the abdomen (black circles), forelimbs (grey triangles) and ventral part of the abdomen (control treatment) (white circles) painted on blue. The line represents the fitted value of the probability of capturing a honeybee.
Figure 9.
Effect of blue spots on honeybee behaviour (Experiment 3).
Histograms showing the expected frequency of the number of honeybee visits to blue inflorescences when honeybees are equally like to visit control and blue inflorescences (black bars) and the observed frequency for the number of honeybee visits to blue inflorescences in Experiment 3 (white bars).
Figure 10.
Effect of spider movement on honeybee behaviour (Experiment 4).
Effect of spider movement and position on the probability (± SE) that honeybees landed on spider harbouring inflorescences.