K-wing bees at the entrance — are tracheal mites still a thing, and how would I even check?
Uppsala, third year, four hives. The last few days I've been seeing a handful of bees on the landing board of one hive with their wings held out at odd angles — the front and back wings unhooked so they make a sort of K shape. They walk around, sometimes try to fly and can't. Maybe ten a day, not hundreds.
I did a search and every older book says K-wing = tracheal mites, Acarapis woodi. But nobody at my club has ever mentioned them and my mentor sort of shrugged and said "that was a 1980s problem". My varroa wash three weeks ago was 2 per 300 after Apiguard, so I don't think this is the same thing as the deformed-wing posts.
So: are tracheal mites still around in Europe? Is K-wing actually diagnostic for them? And is there a way for a hobbyist to check, or is it a lab job? I don't want to shrug at something just because my mentor does.
#tracheal-mites#k-wing#acarapis-woodi#diagnosis
▲ 8 votes💬 4 replies
4 replies
MieleMarco · Sep 21, 2026
Still around, just rarely a problem any more. Acarapis woodi lives in the breathing tubes of the thorax, and it faded mostly as a side effect: formic, thymol and amitraz used against varroa all kill it too, and decades of selection (Buckfast came out of the Isle of Wight years) left bees that groom them off. K-wing is NOT diagnostic on its own — I see it with nosema, virus, and plain old bees on their last day. To check, dissect: pull the head and first pair of legs off ~30 bees, slice the thorax collar, look at the trachea under 20-40x. Healthy is pearly white; infested is blotchy brown.
GeorgiaWes · Sep 21, 2026
MieleMarco has it. I lived through tracheal mites in Georgia in the late 80s and early 90s — whole apiaries crawling in the grass in March. Haven't confirmed a case in fifteen years. Ten K-wing bees a day at a hive of 30,000 in autumn is background noise, worn-out summer bees dying off. If you want peace of mind, your national bee lab will do the dissection for a small sample, but I'd spend the worry on your winter stores instead.
ImkerinLena · Sep 22, 2026
Small addition: in Germany the bee institutes still find A. woodi occasionally in samples, usually in untreated colonies, so 'extinct' is wrong but 'rare' is right. If you enjoy the microscope, a dissecting scope and a razor blade is all it takes and it is a satisfying skill. I would also look for nosema in the same session — crushed abdomen, 400x — since that is a more likely cause of crawling bees in a Swedish autumn.
LindenNora · Sep 22, 2026
Thank you — this is exactly the level of answer I wanted. 'Background noise' makes sense given the numbers, and I like the idea of learning the dissection anyway. We have a club microscope; I'll try 30 bees this weekend and do the nosema squash at the same time. Will post pictures if I find anything interesting.