It is mainly the work of Justin O. Schmidt, who was an entomologist at the Carl Hayden Bee Research Center in Arizona.

Schmidt published a number of works on the subject and claimed to have been stung by the majority of stinging Hymenoptera.

Later revised versions of the index added Synoeca septentrionalis, along with tarantula hawks as the only species to share this ranking.

[4] In September 2015, Schmidt was co-awarded the Ig Nobel Physiology and Entomology prize with Michael Smith for their Hymenoptera research.

[2] Many small bees are categorized into a pain level of 1, with their venom containing polypeptides such as melittin, apamin, and MCD peptide.

"[3] Also rated into pain level 1, Schmidt has described the sting of a sweat bee as "light, ephemeral, almost fruity.

[1] Schmidt described the sting as "pure, intense, brilliant pain...like walking over flaming charcoal with a three-inch nail embedded in your heel.

However, with the evolution of sociality where many Hymenoptera cluster together in colonies, nests become a nutritionally rich and therefore worthwhile target.

In order for sociality to evolve, Hymenoptera needed a defence beyond a painful sting to protect their whole colony.

With a toxic sting, and thus the ability to protect against predators, Hymenoptera were able to progress towards sociality and its associated evolutionary benefits of the shared raising of youth, individual task specialization, inter-colony communication, and food storage.

[10] To approach studying this evolutionary connection between toxicity and sociality, Schmidt recognised there needed to be a quantitative measure with which to score the painfulness of stings.