Tomatoes - Russet Mite Wars Pt I

If there's a heaven and hell for the plant world and we had some choice in the matter, I would consign a special place in hell for the Tomato Russet Mite (Aculops lycopersici) - pest of the ages.

The tiny mites - so small you need a microscope to see them - feed on the Solanaceae family but are particularly at home feasting on tomato plants. They seem to pop up regularly at my place around mid to late summer and, without treatment, slowly destroy my tomato crops.

To the naked eye they appear as a dull bronze coating, starting from the bottom of the main stem then creeping higher. Affected foliage will initially go yellow then a crispy (dead) dull tan. Without treatment plants eventually lose all their vigour. While they may 'live' until April they won't crop well and be on death's door. 

The typical bronzing of stems & crisping of foliage caused by Tomato Russet Mite

I can't get on top of Russet Mite, I have to be honest. I'm writing this post out of frustration rather than wisdom. There are treatments for the mite but they are labour-intensive and not suited to the occasional or lazy gardener. What's more, you'll have to settle for never getting rid of the critters; control rather than elimination is the realistic goal.

Wettable sulphur seems to be the treatment of choice for russet mites. I've tried this for a few years and it does work, but you have to get the fine details right and be vigilant with repeat doses. Plus it's fiddly and annoying.

You can get WS as a powder in small containers at nurseries and hardware stores. You mix it with water in a bucket or watering can at a strict ratio, then transfer it to a spray bottle for spraying over all the surface area of your tomato plants.

There are several hassles. Firstly sulphur is very acidic, so don't be tempted to go with a concentrated mix as it'll burn your plants. Secondly the risk of burning increases with temperature, so pick a cool time to apply. They say don't spray at all over 32 degrees. My bigger concern is what happens with existing sulphur residue once the temperature (previously OK) pops over the threshold?

Then there's the fact that rain and watering takes the sulphur off unless you take precautions. And like a lot of natural products you have to periodically reapply. The spray nozzles can get clogged with undissolved sulphur powder.

I probably sound like a big whinger. But I do find the whole use of sulphur very fussy and labour-intensive. There has to be a better way. To be honest I haven’t found it. As at the time of this post (early May 2020) I am once again letting my yellow cherry tomatoes surrender to the slow, creeping might of the Mite. At least I got a decent harvest beforehand.

What have you been doing to combat Tomato Russet Mite? Please feel free to add your thoughts in the Comments section below.