Spider mite in greenhouse

[carly]

Got an infestation on beans and aubergine of red spider mite. Shall I remove all infested areas? I have begun taking leaves off but things are starting to look bare
What’s best?

[Jungle Jane]

I always get spider mite on cucumber plants I grow in my house,I don’t have a greenhouse. They don’t affect any of my plants outside so put the plant outside if you can & spray both sides of the leaves with soapy water to try & keep the plants growing. Beans are a bit hard to move,if you removed the plants that are infested,would they begin to infest another plant? You might be better off spraying daily & just keeping the numbers down,it does disrupt them..

[DannyK]

There is a biological control.

[unclefudgly]

Unfortunately if you get them once they will come back year after year. The only solution that works is to introduce predatory mites as soon as you see them, as it can take 4-6 weeks for the predatory mite numbers to increase to a sufficient level to tackle the infestation.

Make sure you clean greenhouse for winter and if possible, let the frost get in. None of which is ideal if you use your greenhouse year round.

Best time to add predator mites is around May-June

[carly]

Unfortunately if you get them once they will come back year after year. The only solution that works is to introduce predatory mites as soon as you see them, as it can take 4-6 weeks for the predatory mite numbers to increase to a sufficient level to tackle the infestation.

Make sure you clean greenhouse for winter and if possible, let the frost get in. None of which is ideal if you use your greenhouse year round.

Best time to add predator mites is around May-June

We don’t grow over the winter so we do plan on cleaning the whole greenhouse in November/December. Will the frost help with killing off RSM then?
I did get some ladybird larvae in end of may but that was mainly for aphids.... which they got rid of in 4 days. I just had some more ladybird larvae delivered 2 days ago and I have put them all where the rsm is so hopefully they will help. We did look at Phytoseiulus but you have to keep the greenhouse within certain temps for them to work under 30 and over 10 and with all this hot weather we wasn’t sure whether we would be able to achieve that so decided to go for the lady bird larvae again.

[unclefudgly]

They are horrible little buggers that's for sure. I think it's important to get rid of their hiding places in which they hibernate, so clear all dead leaves, take out all pots etc etc. The less hiding places the better. Apparently the eggs can survive zero degrees but unsure about hibernating adults, so maybe worth a try.

In Spring I add Amblysieus spider mites, before I even see a spider mite, just hang the sachets around the greenhouse. Amblyseius is active over a much wider range of temperatures than the other type.

This year I managed to control them a little bit better than previous years by adding predator mites early, and numbers didn't damage my long bean crop too badly, and even the Aubergines survived