Predators can exploit the sensory biases of prey to increase their foraging success. Crab spiders, Thomisus spectabilis, use flowers to prey on the honeybee, Apis mellifera. Many flowers exhibit symmetry, and innate preferences for symmetry in pollinators such as honeybees are documented. Choice experiments were performed to test the prediction that crab spiders exploit a bias for floral symmetry in honeybees. Flowers (Argyranthemum frutescens) were manipulated to contain asymmetrical and symmetrical patterns, with olfactory cues excluded. In the first experiment, crab spiders and honebees were presented with one asymmetrical and one symmetrical flower and choices recorded. Both crab spiders (62.5%) and honebyees (62.5%) exhibited a significant preference for symmetrical flowers. However, the predicted independent probability of a spider and a honeybee selecting the same flower of a pair, calculated from the observed percentages, was 0.53. Whilst close to chance, this may provide sufficient opportunities for crab spiders to capture prey. A second choice experiment tested preference for radial symmetry, but no corresponding effect was recorded in crab spiders. Further analysis demonstrated that spider condition, flower reflectance or orientation of the axis of symmetry did not affect crab spiders' decisions. An analysis of spider choices in the field of A. frutescens revealed no significant difference in the standard deviations of petal lengths between occupied and unoccupied flowers. Spiders and honeybees may use another flower characteristic, for example olfactory cues, in combination with floral symmetry, in making their foraging decisions.
|Number of pages||2|
|Publication status||Published - 2003|
|Event||Australasian Society for the Study of Animal Behaviour Conference (30th : 2003) - Canberra, ACT|
Duration: 24 Apr 2003 → 27 Apr 2003
|Conference||Australasian Society for the Study of Animal Behaviour Conference (30th : 2003)|
|Period||24/04/03 → 27/04/03|