No point in reinventing the wheel. Here are links to some guides in sorting out some species that we often encounter during Spring, March, April and on into May. It’s not a comprehensive list. Feel free to add further resources in comments and I may add it to article. All thumbnails link to the species album in the image archive.
Orthosia species (Quakers etc)
This guide features Common Quaker Orthosia cerasi, Clouded Drab Orthosia incerta, Hebrew Character Orthosia gothica, Twin-spotted Quaker Orthosia munda and Small Quaker Orthosia cruda, all widespread in Ireland.
Lead-coloured Drab Orthosia populeti is also mentioned, but it is rarely recorded in Ireland, but useful to know what features to look out for.
Further into April other species appear and Birdguides have
This includes Powdered Quaker Orthosia gracilis and Red Chestnut Cerastis rubricosa Other species mentioned are Northern Drab Orthosia opima which is rare in Ireland and Blossom Underwing Orthosia miniosa which is presumed extinct.
Early Tooth-striped/Mottled Grey
Separating Early Tooth-striped Trichopteryx carpinata and Mottled Grey Colostygia multistrigaria can be problematic, but help is at hand.
We all need help with Pugs! and Lancashire Moths have come up trumps again!
This guide covers our species quite comprehensibly. In early Spring, the 2 most likely species are Brindled Pug Eupithecia abbreviata and Double-striped Pug Gymnoscelis rufifasciata but as we head through April may others species turn up.
Not specifically Spring, but worthy of inclusion, particularly if you starting to look into the world of micro-moths.