Regulation and Non-Toxicity of the Spit from the Pale Spitting Spider Scytodes Pallida (Araneae: Scytodidae)


Reuben Clements, Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543. E-mail:


The pale spitting spider Scytodes pallida (Aranae: Scytodidae) has a unique habit of spitting a glue-like and possibly toxic substance at its prey to render them immobile prior to envenomation. Quantitative behavioural studies involving the spit, a first for S. pallida, demonstrate that the spider regulates its spit expenditure when offered prey of variable sizes and struggling intensities. This behaviour interestingly mirrors the regulation of venom expenditure according to prey sizes and difficulties exhibited in other non-spitting spiders. The spit, however, did not appear to have any toxic effects on different prey types exposed to the spit, opposing the long-standing belief that the spit from scytodids can poison prey.