Systemic insecticide for red spider mite

[Mike]

Hello everyone.
Is there a systemic insecticide (available in the UK) that is effective on red spider mite? I have a degree of success with contact insecticides, but with some plants it's all but impossible to get to all affected parts. So, I've tried Bug Clear Ultra, which after two applications has not been 100% effective as a systemic insecticide. All suggestions welcome!
Mike

[Phil_SK]

I don't think so, no.

[CactusFanDan]

Nope. The neonicotinoid based insecticide you've been using are ineffective against mites (as you've found out!). You can buy Floramite and Avid on eBay, which should both be quite effective against mites.

[Nick_G]

The only 'cure' I have found for RSM is to take the affected plant out of the greenhouse and leave it unprotected in the garden somewhere for the summer. This year has been a bad year for RSM with me, quite a few Sulcos badly scarred.

[Mike]

I've also been using a specific miticide as a spray. But with plants such as Ipomoea platensis which is a climber, getting this to all parts is very tricky, as would getting them out of the greenhouse!
mike

[DaveW]

I did overhear somebody at the Convention saying they used diluted Dettol to kill red spider mites. He said everybody says it should not work, but does. I have never tried it and don't know what would be the safe dilution for plants, but searching the Web I find some poultry keepers do use it for red mites:-

"I can't recommend Dettol enough - we had a monstrous outbreak of redmite, and followed the advice from a local chicken guru.20% solution of Dettol, clean out house really well and spray every nook and cranny. Let the house dry and put everything back in. Repeat every 2 or 3 days for a couple of weeks, then spray once a week with the regular cleaning."

Of course that 20% solution is not being sprayed on chickens or plants, so that strong may cause trouble. Maybe if it is tried on some cuttings or offsets that don't matter safe dilutions could be found?

"What is Dettol?
The active ingredient in Dettol liquid is an aromatic chemical compound known as chloroxylenol, which makes up 4.8 percent of Dettol's total solution. The remainder is a mixture of pine oil, isopropanol, castor oil soap, caramel and water."

Of course it could be the pine oil or soap that kills the mites.

http://en.wikipedia.org/wiki/Dettol

Also from the Web, overuse of insecticides can increase red spider infestations:-

"One reason that spider mites become problems in yards and gardens is the use of insecticides that destroy their natural enemies. For example, carbaryl (Sevin) devastates most spider mite natural enemies and can greatly contribute to spider mite outbreaks. Malathion can aggravate some spider mite problems, despite being advertised frequently as effective for mite control. Soil applications of the systemic insecticide imidacloprid (Merit, Marathon) have also contributed to some spider mite outbreaks."

http://www.ext.colostate.edu/pubs/insect/05507.html

Never used any of the above so cannot say they work, so test on a plant that does not matter.

[iann]

Job #1: find out what pests you have. People bandy around the term red spider mite, but I have serious doubts about 90% of the cases. Google "flat mite", "Brevipalpus", and "false spider mite", then compare with your critters.

Neonicotinoid insecticides are toxic to most mites despite them not being insects. However there are many studies (do we need more? They keep doing them) show that they are frequently/usually ineffective at controlling mites (various species of commercial importance) in a field environment. This is presumably due to a combination of effects such as by-kill of mite predators and increase in mite breeding rates.

Of the neonicotinoid products still available in the UK, only Bug Clear Ultra (Acetamiprid) is labelled for red spider mites. Bayer products are not labelled for mites (except the aerosol, see later) although toxicity and effectiveness in trials seem to me to be largely similar to Acetamiprid. Imidacloprid, no longer available but chemically almost identical to the Thiacloprid that is available, has a long history of studies showing increases in mite breeding after treatment. Bayer products were labelled for red spider mites until about ten years ago.

The Bayer aerosol contains both Thiacloprid, of doubtful effectiveness against mites, and Methiocarb, toxic to almost everything. I have found the previous incarnation of the aerosol with Imidacloprid to be extremely effective against the flat mites that are the only pest mites ever found on my globular cacti. The effects are persistent enough that perhaps the Imidacloprid was having a long-term systemic effect. Or maybe the mites just don't like the smell of methiocarb, who knows.

I have recently tried Acetamiprid spray against mites, both flat mites and spider mites, since it is labelled for that, other miticides are getting difficult to find or expensive, and rotation is always good. The results have been good. It certainly kills them and appears to prevent reinfestation for some time, so possibly are operating systemically against the mites. There is no other active ingredient in the spray.

In all cases, mites can develop resistance to any poison very quickly, so if you try anything and it doesn't seem to work, try something else. Mites can't become resistant to soap and oil sprays, but they are highly likely to scorch or mark succulents, so only use with great care.

[Werewolf]

Thanks, Iann, the response I was waiting for on this thread!

[gerald]

Nope. The neonicotinoid based insecticide you've been using are ineffective against mites (as you've found out!). You can buy Floramite and Avid on eBay, which should both be quite effective against mites.

They're quite expensive, do they work?

Just found my Cintea knizei with classic RSM symptoms. I check my plants every day - yesterday all ok, today some rusting at the apex and some absolutely tiny red mites, barely visible to the eye in the vicinity of the rust.

I have some Bug Clear Ultra at hand so it's been liberally sprayed and quarantined. I hope that's the end of it but the concern is that it could just happen again randomly to any plant at any time.

[delandmo]

generally spreads to adjacent plants. Spray nearby plants as well. spray the same plants again in a couple of weeks to catch further hatches.