Spider wasps (family Pomilidae) are solitary wasps that get their name from hunting spiders. After being stung by a pompilid wasp, spiders can stay paralysed for up to several months serving as a fresh food source for the wasps’ larvae to feed on. While pompilid wasp venom can cause paralysis in spiders, defensive stings can also cause severe local pain in humans. For example stings of the Tarantula hawks (genus Pepsis), large species from the Americas, are extremely painful with the second highest score of any hymenopteran sting on the Schmidt sting pain index.
My aim has been to uncover the venom composition of Tarantula hawks; to identify the major pain-causing toxin(s); and to understand their mode of action. I have used a combination of methods, including proteotranscriptomics and bioactivity assays, to analyse Tarantula hawk venoms. Tarantula hawk venoms contain several proteins that are commonly found in Hymenoptera venoms, and there are several highly expressed unusual peptides. I will present an overview of peptides and proteins found in these wasps’ venom and discuss the potential functional role(s) of individual venom components. The identification of new peripheral pain mechanisms can potentially drive the development of novel analgesics.