I gave up in my google searches for a site with pictures of ligustica, mellifera, carnica, cecropia etc etc.The main criterion I use is that melleferan bees have a wider segment on the abdomen than carfnican. Ligustican are generally yellow, though there are reports in the US that they can be bred black! Though many of my haive contain a proportion of hybrids, showing an orange colour in this segment, usually dull, even onl;y part of it light brown, the rest are either black or dark brown. I see no obvious evidence of carnican, even though from time to time we hear of them being brought in near enough for drones to reach us. I have not yet measured anything else except occasionally wing venation - which I will do again an March in a workshop in Cornwall run by BipCo. I am hopeful I will get some genetic information soon.