I tried yesterday to get a pic, no chance, impossible task without a macro.
Wrasse are on the agenda anyway as I just cannot 100% eradicate nudis, even when I did a strirct dip scrub and milliput the basal loss on eggcrate racking away from live rock. Digitata is free of them though, so I am ruling out a similar relationship as red bug and aefw have (predictor and prey it seems)
Though tbh, I would prefer to avoid sixline/mystery types due to aggression in the long term, catching the clever little sods is not easy
Interceptor is near impossible to get into the UK unless you have a friendly vet in tow. Fwiw I used cuprazine on my acropora against the red bugs (I believe it worked as was 3 months ago) (no acro weren't impressed much)