Pear Leaf Blister Mite - Can it spread to apples?

Can you put up a picture?

Are you certain it's blister mite and not scab - or damage from chilly winds? Given the very wet weather in recent weeks, scab is entirely possible; it's been very wet here and my unsprayed trees are showing lots of defensive reactions to scab as their resistance kicks-in to stop the infection.

If you treated for blister mite (assuming you can find a systemic insecticide-type product which can kill them), it would not be effective if the diagnosis was actually scab.

Diseases from one type of plant can sometimes spread to other different plants, but is unlikely to affect them as badly, and may not affect them at all.

Personally, rather than spray rather frightening chemicals without the properp chemical-handling training (which may end up with chemicals being transported into the fruits which I later eat), I prefer to let nature take its course, or simply literally "nip it in the bud" if I notice something particularly nasty.

I would suggest plenty of feeding (a good balance of NPK) and adequate, regular watering to help them outgrow the problem.

The camera on my phone is knackered at the moment but having googled images of scab, it doesn't look like it. This photo from google is EXACTLY what the whole tree looks like, including the leaves that haven't opened up yet. It's only a dwarf tree (just over a meter tall) so if there is any risk of it spreading to the apple trees I'd rather get rid.

It's in a sheltered spot so it doesn't get wind particularly and is protected from driving rain. If it is indeed pear leaf blister mite then I don't know where it came from

I only tend to spray stuff I can buy in a garden centre - if people suggest a home made equivalent then I'm happy to try it (things like home made plant food, but not things with lime or sulphur - as you say, that stuff would require training to handle I'm sure). I cannot find any insecticides to treat for this.

As you mention that your plant is very sheltered, I expect that it is blister mite; apparently pears in unusually sheltered/mild spots are very prone to it.
So moving it to a less sheltered spot (but not too cold/windy!) should bring it under control.

It would have been best to pick-off the first leaves to show infestation, but it sounds as if it is so severe that you'd have to remove all the leaves. This could then kill the plant, so it's better to leave the leaves so that the plant can gather some sunlight from the portions of each leaf which aren't damaged.

I doubt that the mites would have much interest in the apples, although a minor spread of the mites may show itself later; my apple trees occasionally attract unusual pests from other non-apple trees nearby.
Even if the mites were contagious (from pear to apple) the infestation on the pear is now so advanced that thousands of mites will literally be crawling everywhere in the vicinity. If the apples are going to get it, they will already be incubating the infestation which may take a few weeks or a few months to show itself; but if they're going to get it, it's too late now to worry about it as they've been heavily exposed.
Besides; if the mites found their way to a previously healthy pear, what's to stop them returning from wherever they came to attack other plants?
If one of your neighbours has an infested tree, there's nothing you can do to prevent the mites returning to attack your pear or your apples. But by moving to a more open/airy/rain-wetted spot, you can let nature deal with them.

So I suggest your best course of action is to live with it, but to take actions which will reduce the effect of the mites - such as being vigilant for the first signs of infected leaves (and "nip it in the bud") and to put the trees in a more open spot where they can get a bit of rain on the leaves and a bit of a breeze.
Parasitic mites are often eaten by other garden predators, so it may be that putting the plants further into the garden will encourage predators to come for a feast and eliminate your problem.

By the way - pears are usually among the least troubled by pests, in my experience.
Just wait until the woolly aphids find your apples (woolly aphids also like sheltered spots).

Here you go - a picture claiming to show pear leaf blister mite damage on Rowan:

GAP Photos - Garden & Plant Picture Library - Phytoptes pyri - Pear leaf blister mite on rowan - GAP Photos - Specialising in horticultural photography

But, like I said earlier; the mites which attacked your pear will be lurking in or near your environment, so they will not easily be got rid of, and will probably come back unless you make changes to the way you grow your trees.
If you get rid of the pear tree, the mites wandering in the local area will have little choice but to look for something else to attack; maybe the pear is sparing the apples from being attacked since the mites prefer to attack pears unless they're really hungry.
Certainly I grow a couple of apple varieties specifically to draw all the maggot attacks, which leaves the rest of my trees almost completely undamaged. Kind of companion/sacrificial planting.
Same with woolly aphids; I have a couple of sacrificial trees which get massacred and have to be literally hacked to the ground every year, but most of the rest of my trees remain relatively undamaged (I also have a few with strong natural resistance as I prefer no-spray and minimal intervention).

My garden's not really big enough to grow a tree for sacrificial purposes. I picked all the leaves off and gave the tree two chances. The new leaves are looking completely untouched so hopefully I've managed to partially solve the problem. I'm probably going to move it at some point next week. Will have to have a think about the best place to put it then.

I have posted some info before about the treatment to minimize the damage caused by these b**gers. I can't remember which thread it was but it involves spraying with a little veg oil, diluted with warm water and some detergent to dissolve the oil. Spray it onto the tree just prior to bud burst in the spring and it will kill off the bugs that overwinter in the bud scales. I did this early this year and the tree has been much much better with just a few affected leaves which I have picked off. Did not get much fruit set though, but may have been due to the weather.

After picking off nearly all the leaves it looks quite healthy - lots of new ones and all nice and shiny with no sign of them

I've moved it to a new place so hopefully that may help next year but I'll try that wash that you suggested too. (ps - my apple trees are untouched too despite what some people said). Thanks!

How does your pear tree look now?
Did you try the wash as suggested?

I didn't try the wash the other year. I went with a do or die option and pulled all the leaves off. It sprouted new ones and has been fine since. This year it is covered in blossom - the first year it's flowered so who knows, maybe I'll get some fruit this year! It's the 3rd or 4th year (3rd I think) it's been in so fingers crossed...

Many Thanks for replying.
I have the same problem so hopefully removing some leaves will cure the problem, or at least bring it under control.
Once again
Many Thanks

I don't know that it was definitely blister mite but the Google pictures matched how my tree looked. It was only a £20 tree so had it died then it hadn't cost me a fortune. Maybe try the wash too. Can't do any harm!

If the problem is still active late summer, I will use the spray in the winter.
I have definately got Blister mite, and if FB thought you had (and it does look like it)then you had it.

You may find this interesting
http://curbstonevalley.com/blog/?p=10873
I assume the site is in USA, but the best info I have found so far.