Volatile Scents Preference of Crab Spiders (Ebrechtella Tricuspidata) for Host Flowers

Abstract Chemical signals are important to all living organisms, especially to plants which don’t have vision or mobility. Plant volatiles participate in the competition between plants, herbivores and predators; meanwhile, the tritrophic interactions promote the evolution of plant volatiles. To our knowledge, spiders are common predators in the interactions, but only few studies have begun to investigate what floral volatiles do to spiders. Here, we used Ebrechtella tricuspidata and their common host flowers (tulips) found in our previous field survey to determine the volatile scent preference of spiders for host flowers. Eight main floral volatile scent compounds of tulips were picked out and tested in dual choice behavioural assays. E. tricuspidata showed a significant avoidance of α-pinene and no preference for limonene, β-ocimene, linalool, benzaldehyde, benzyl-alcohol, methyl-salicylate, or 2-phenylethanol. The results illustrate that facultative flower visitor E. tricuspidata is not popular among some kinds of tulip. This probably represents a typical response: facultative flower visitors cannot tolerate all defensive floral volatile scents. Compared with previous studies, we detect that the same floral volatile scent compound has different effects on different spiders, indicating that floral volatile scent compounds attract and reject spiders with specificity and they evolved for different functions and targets. However, this is a preliminary study on the effects of chemical signals on plant-spider interactions, both chemical and physical signals should be considered in future research.