Could someone tell me how the difficulty rating on some species groups (eg bees) is derived. Looking to potentially do the same for sawflies. Thanks.
Hi Andrew, the original rules were first derived as part of the NBN Record Cleaner project, with the rules being defined/agreed by the relevant recording schemes. As you will be aware, for most taxon groups that have been included there are sets of rules for ID difficulty, for known distribution, and for known flight/activity period. Most recording schemes worked with a five-point scale, with 1 = easiest to identify through to 5 = hardest to identity, but the precise definition and wording associated with the 1-5 scale was tailored to the species group concerned. There is some more background information on our Help page. The 1-5 scale definitions for aculeate Hymenoptera, as defined by BWARS, can be seen on page 12 of https://nbn.org.uk/wp-content/uploads/2016/02/NBNVerificationRulesFinalReport_Rev2.pdf
There will be some new work done on these rules over the coming months, aimed at making it easier for recording schemes to define new rules or update existing ones, and it would be great to have sawflies represented in this.