My Sage (Salvia officinalis) bush is a right mess at the moment. I should have pruned over the winter, but looking closer it is also heavily infested with insects. It is always hopping with Sage Leafhoppers (Eupteryx melissae), bugs that leave white spots all over the leaves where they suck the sap. But it is even more ratty than previously due to aphids. Researching these (recommended looking at https://influentialpoints.com), these are Sage Aphids (Aphis passeriniana). This species is considered rare in UK, with only 3 records up to 2018, the nearest in Sussex. Judging from the number on my Sage, they seem to find Gloucestershire to their liking, and are likely on the increase in UK.