AusBonsai

hey people,

lets take a look at red spider mites, these are nasty little spider like insects that in large or small infestations can be hazardeous to trees. although name red spider mite they can range in colour including but not limited to black or green. spider mites are just visible to the human eye, a magnifying glass may help in identifying them, but the simplest way is to get an A4 size piece of white paper and tap the foliage of the tree, you might see little dots about the size of a pin head that will start moving around, this will tell you, you have a problem, on some indestations they can be quite readily seen as in the picture below, it speaks for itself. they will also make a visible webbing that looks like debris on the underside of the foliage.
Mites by themselves are not aggressive movers. They pretty much stay on the same leaf or nearby leaves for their entire lives. They are usually worst in dry dusty conditions.
now that we have identified them how do they do damage and how quickly?
Mites usually start becoming a problem in late spring and reach a peak by late summer or just at the peak heat of the season. They are definitely hot weather pests. damage is caused as they feed, bruising the cells with their small, whiplike mouthparts and ingesting the sap. Damaged areas typically appear marked with many small, light flecks, giving the plant a somewhat speckled appearance.
these will generally be but not limited to the older leaves or foliage. spider mite can be hazardous to a tree and if left unchecked can lead to death.
the life cycle of spider mite isnt a long one, generally about 7-10 days but they can reproduce at a very fast rate with mites being mature by the fifth day and have eggs laid by the end of their lifecycle.
this is where the control and iradiaction comes into it.

controlling spider mite can be a touch and go thing, they do have natural predators in the ladybird beetle, minute pirate bugs, big eyed bugs and predatory thrips (which we dont want near our trees either).
due to the spider mites lifecycle and how they can reproduce rapidly sometime chemical sprays need to have several applications to eradicate them all.
in years past white oil was used but is now tended not to be as it can clog up the pores of the tree/plant and possibly push your plant over the edge ( i know this from first hand experience ) chemical control of spider mite generally involves using a specific pesticide specific to spider mite and a second or even third dose might be necessary as pesticides wont penetrate the eggs so it needs to get them after they have hatched but before they can reproduce again.

other control methods include using a jet spray of water blasting them off the tree, or a product like natrasoap can do the trick.

in wrapping up spider mite is better prevented than control and iradication as once the infestation reaches 40 mites per leaf the population can explode and more drastic measures will have to be taken, it could be a case of losing a lot of trees too.
as mites are more a dry hot weather thing by keeping up humidity a bit and constantly checking your trees you shouldnt have it explode to these amounts, after all we have to water our trees daily in most cases so spend the time and check your trees out aswell


if you have any personal experiences or anything to add, or questions please feel free to post it here, if we can create a database on pests and disease it will be a really good reference for beginners and more advanced

jamie

information sourced from evergreengardenworks.com re written by me.
pictures sourced from various locations on the internet

Hi Jamie, dormant sprays of lime sulphur on deciduous trees in late winter are effective in killing the overwintering eggs of Red Spider as well as Aphids. This should in turn keep numbers down on your conifers in summer. Misting conifers and adding humidity in the evening during late spring and early summer is a great preventative measure, Red spider prefers dry conditions. A non chemical treatment that is fairly effective if used early and often is Yates Natrasoap. Natural predators generally will not work well for the majority of bonsai growers due to use of chemical pesticides. In my experience you need at least 12-18 months off the chemicals before beneficial insects are useful.

Cheers
Mojo Moyogi

Even dipping the whole tree into a bucket of double strength rogor won't kill the little blighters.

I use Confidor on a lot of trees for a lot of things but Confidor is NOT RECOMMENDED FOR MITES!

According to a government person down here who does the spraying for a major nursery Confidor acts like an aphrodisiac to the mites. He sprays with a combination of Confidor(cleans up most things) and Mavrick(cleans up the mites) when spraying for mites.

Mites are a problem in Canberra (long periods of dry)if it becomes an infestation and can attack Junipers, Elms, Picea. Best to be pro-active and keep an eye on things.

Grant

Hi everyone,

Not sure if I have mites, but I certainly have something to worry about. I have a Liquidambar airlayer that was severed about 6 weeks ago. It struggled and all its leaves have dried, but when you scrape the bark, the cambium is still green. I bought a tiny bottle of superthrive, as that was the only size I could find to give it a fighting chance. I put it in a tub of water with superthrive to soak, and I noticed all these tiny, and I mean tiny little spider-like creatures most of which were red, although some were white. They were happily running across the surface of the "soil" which is diatomite, zeolite, and pine bark minis with a bit of Dynamic lifter on top. Also I noticed heaps (more than the spider-type creatures) of little flying bugs about the same size as the "mites" which could be mosquito larvae/hatch-lings

Could these be mites even though the affected tree has no foliage? Would they take a likening to dynamic lifter to lay eggs? Or could they be the reason I have dried dead foliage on this tree?

What are my options? I want to try and save this tree, but it may be well and truly beyond that. If I discard the tree, how can I treat the diatomite/zeolite to make it safe to re-use?

What is a good miticide to use?

Thanks guys,

Luke

Hi Luke

I reckon the dynamic lifter is attracting All sorts of flys / bugs probibly not the reason the layer is failing
And I don't think its a good idea to use dynamic lifter on pot plants it can become clogy reducing drainage and also can make the soil ph increase becoming alkaline .
Did the layer have plenty of roots? and did u disturb the roots? Did u tie the new layer into the pot so it couldn't move about in the wind ?

Paulneill wrote:Hi Luke

I reckon the dynamic lifter is attracting All sorts of flys / bugs probibly not the reason the layer is failing
And I don't think its a good idea to use dynamic lifter on pot plants it can become clogy reducing drainage and also can make the soil ph increase becoming alkaline .
Did the layer have plenty of roots? and did u disturb the roots? Did u tie the new layer into the pot so it couldn't move about in the wind ?

It only really had roots on one side that seemed enough to support it. I did not disturb the roots, in fact I left the sphagnum in place as I know the roots are fragile. And yes I tied it into the new pot to support it. I just dont think it had enough roots to support itself, but I am praying to the bonsai gods that it will survive, as it has amazing bark on it.

I agree with you about dynamic lifter impeding drainage also

Luke, At this time of year trees under stress will often drop all the leaves and go dormant early but usually sprout in the spring. It could be you left a bit too much top growth on for the few roots it had but hopefully it will survive.

Don't use miticide unless you really have mites so you need to check what bugs you actually have. Capture some and take to a nursery for id and recommended treatment. Mites have 8 legs. Fungus gnats breed in decomposing organic material and like Dynamic lifter. The larvae are white grubs and the adults are tiny flies but should not affect the tree.

I am happy to use some pelletised chook poo on my trees but not too much and use other ferts as well.

You can sterilise any potting mix in the microwave or in an electric frypan. I put a 4l icecream container of damp mix in the microwave on high for 15 min (less would probably do but I want to be sure!)
I think the temp to aim for is 72 deg C (pasteurising temp which kills most pathogens and would certainly kill any bugs, eggs, etc) but I aim to bring it to boiling point (100C) to be sure there are no cool spots left in the centre, etc.

shibui wrote:Luke, At this time of year trees under stress will often drop all the leaves and go dormant early but usually sprout in the spring. It could be you left a bit too much top growth on for the few roots it had but hopefully it will survive.

Don't use miticide unless you really have mites so you need to check what bugs you actually have. Capture some and take to a nursery for id and recommended treatment. Mites have 8 legs. Fungus gnats breed in decomposing organic material and like Dynamic lifter. The larvae are white grubs and the adults are tiny flies but should not affect the tree.

I am happy to use some pelletised chook poo on my trees but not too much and use other ferts as well.

You can sterilise any potting mix in the microwave or in an electric frypan. I put a 4l icecream container of damp mix in the microwave on high for 15 min (less would probably do but I want to be sure!)
I think the temp to aim for is 72 deg C (pasteurising temp which kills most pathogens and would certainly kill any bugs, eggs, etc) but I aim to bring it to boiling point (100C) to be sure there are no cool spots left in the centre, etc.

I am hoping it has gone dormant early . I removed about 2/3 of the foliage after severing, but maybe that wasn't enough. I will have to watch it patiently til spring.

As for catching the "mites" I think that would be near impossible as they are only just big enough to see with the naked eye.
Thanks for the advice though

Hi guys, i have a spider mite problem on one of my junipers so i used multicrop Eco Pest Oil on it last night and noticed that all the foliage has changed colour to a lighter green overnight It has a big Organic sticker on it so i stupidly thought 'it must be ok, what harm could it do'
Has anyone used this stuff before?
what was the outcome?
will my tree eventually die from being sprayed?
Will it regain its original colour again?

any thoughts?

TreeHugger wrote:Hi guys, i have a spider mite problem on one of my junipers so i used multicrop Eco Pest Oil on it last night and noticed that all the foliage has changed colour to a lighter green overnight It has a big Organic sticker on it so i stupidly thought 'it must be ok, what harm could it do'
Has anyone used this stuff before?
what was the outcome?
will my tree eventually die from being sprayed?
Will it regain its original colour again?

any thoughts?

white oils and the like shouldnt be used on junipers, it actually clogs the trees breathing holes and will suffocate the tree. I did the same thing and lost 3 prized junipers a few years ago..

make a proper ID by getting a sample and taking it to your local nursery. then use control methods as recommended. best way to keep your trees from this sort of thing is to keep them in the best health you can. a tree has natural defenses for infestations and can generally fight them off themselves if the tree is in good-great health. I rarely have any pest/fungus/bacteria problems because health is a key importance.

white oils and the like shouldnt be used on junipers, it actually clogs the trees breathing holes and will suffocate the tree. I did the same thing and lost 3 prized junipers a few years ago..

make a proper ID by getting a sample and taking it to your local nursery. then use control methods as recommended. best way to keep your trees from this sort of thing is to keep them in the best health you can. a tree has natural defenses for infestations and can generally fight them off themselves if the tree is in good-great health. I rarely have any pest/fungus/bacteria problems because health is a key importance.

Thanks mate.........absolutely shattered!!!!

You live and learn i guess

here endith the lesson

Just thought I'd update
Good News It seems that the "multicrop Eco Pest Oil" i used hasnt killed my Juniper although it has lost its blueish hue it still looks quite healthy and im hoping that the original colour will return in time. After reading some more info and talking to a few nursery guys the notion that pest oil is less harmful than white oil seems to be correct however i probably wouldnt recommend it on your conifers unless you are happy with the colour change that happens from the oil on the foliage

To say im a happy man is an understatement