The tale of the Holly leaf miner (Phytomyza ilicis) is a tangled one. Way back in December 2016, I blogged about the leaf-mining life of this tiny fly’s larvae. Then, early in 2020, doubt was cast on the true identity of this leaf miner, when two scientists published a paper, stating that, through genital examination of one particular Phytomyza ilicis specimen, they had determined there were in fact two very similar species to be found in Britain. Of course, this called into question the true identification of all prior records, and no subsequent records could be confirmed without genital examination of specimens.
At that stage, I stopped recording leaf mines on Holly. But now I can start again because the work of those earlier scientists has recently been disproved. The organiser of the Agromyzidae Recording Scheme (the family to which Phytomyza ilicis belongs) re-examined the questionable specimen and found the genitals had actually been damaged, which had led to them being wrongly identified.
So, until that ‘other’ Holly leaf miner (Phytomyza jucunda) makes its way from Europe to Britain and so long as the mines look similar to the various ones I’ve included here, it is safe to record the Holly leaf mines we see as Phytomyza ilicis.