could anyone help identify these brown bumps on the underside of orchid leaves? The leaves feel a bit sticky, but the bumps themselves quite crunchy, it doesn't seem like there's anything inside.
thanks in advance,
Those look like scale insects ... rub them off ... if they need a bit of encouragement I would use cotton wool balls soaked in methylated spirits to rum them with.
You can clean the leaves with a mix as described here - scroll down to Handy Hints