Q & A forums: Other

Greenfly (Aphids) can only be controlled in the short term by the predation of Ladybirds and other small beetles, or a very bitter winter (to kill them off as eggs, over-wintering on the bark and leaf litter) or by removing trees they favour, or by the use of insecticides. As they reproduce asexually (you only need one), their numbers can explode in a very short period of time and it can take time for their natural predators to increase in population, in order to control their numbers. As a summer progresses, their numbers do normally decline, but not always. Ladybirds are on the decline, despite the growing populations of Aphids, so letting natural methods sort out the balance, doesn't always work. You can however buy Ladybirds. They are shipped to you alive in boxes and you release them into your infected environment. This works well in greenhouses, where they can't fly away, but of course cannot be controlled outside. You can spray the tree with systemic insecticides, however they aren't selective and will kill all insects that they come into contact with, potentially making a bad situation worse. The sticky stuff is what the Aphids excrete and consists mainly of sugars and water. This is why it feels sticky and when left to dry, the sugars attract the attention of sooty moulds, which then cause everything covered in the residue to discolour. The scale infection is easy to control and involves using a soft-bristled brush and soapy water to scrub them off. This control method is also temporary. However Scale insects cannot reproduce asexually and are limited in the number of times they can reproduce in a year, so population increases are much slower.
The only long term way to deal with Aphids is to remove the tree. Sycamores are a favourite of Aphids and if you have an adjacent park filled with Sycamores, then you'll always have Aphids. Some people choose to spray their trees each year, recognising that they will always have to carry out such an action, or buy effective quantities of Ladybirds. If you really like the tree and have the spare cash you could employ either of these control methods on a regular basis. If you don't, then you are probably better off spending your money on removing the tree. If you do decide to remove the tree, just remember to make sure it isn't protected, either by falling in a conservation area or being the subject of a specific tree preservation order. A competent tree contractor should check this out for you, but do not assume they will. If the tree is protected and is cut down, the local authority may pursue you with heavy fines (£10,000 for a tree in a conservation area & £20,000 for a TPO tree). A phone call to your local planning department will be able to give that information.
If you don't like the idea of cutting down a tree, you could always consider a replacement and there are a huge number of trees well suited to small gardens (never grow too big or oppressively), with much more interesting seasonal shows of colour, flowers and fruit, readily available.

It would appear based on the symptoms described, that you have some vegetation infected with honeyfungus (Armillaria spp). Of course, this without me inspecting the site or the dead specimens.

This is a parasitic fungus that normally kills it's hosts and uses the hosts as a food source to travel via rhizomorphs through the soil, to it's next host. It can be responsible for destroying a large amount of vegetation in a garden.

You normally see yellowy mushrooms ( http://fungifinder.arborhelp.com/armillaria-mellea), around the base of these affected shrubs and trees in autumn - they only last for about a week and then deliquesce into a black mush. However the
fungus doesn't always produce fruiting bodies. Sometimes you might find tarry spotting on the stem of the affected host, but again, not always. If you peel away some of the bark of a victim, you will find white mycelium on the wood. If you brush away the soil by hand around the base of a victim, you should find the black bootlaces (rhizomorphs), that are the give-away for honeyfungus - you may even find them on the stem too.

There are control treatments for this fungus. However there are also a number of solutions on the market that claim to kill this parasite, but they can't - Armillatox is one such product - you would be wasting your money buying these sort of products. Currently no fungicide has been shown to provide any lasting control of armillaria.

Control measures, among other things, would consist of:

1. Mercilessly removing any infected stock - you would know them to be infected, because they would start to show poor vigour, sparse foliage, or even dieback or an unusual amount of dead bits. You would have confirmed this by tearing away some bark and observing the white mycelium and discovering black bootlaces around it.

2. Removing any dead stumps in the garden.

3. creating barriers in the soil around infected areas.

4. removing contaminated soil.

5. Re-stocking with resistant species.

Let me know if you need further clarification on any of the above. Also if you don't find any of the indicators for honeyfungus, there are one or two other pathogens that can cause this sort of problem, but honeyfungus is by far the most common of them, so look for this first. If you want help in diagnosing them and have a digital camera handy, send me a few pictures of what you find and I might be able to help further.

On the basis of your website ( http://fungifinder.arborhelp.com). I think I have identified some bracket fungus which is growing on my Greengage tree. The tree is very old and I am keen to preserve the tree if possible. I believe that the fungus maybe Fomes Formentarius (Hoof or Tinder Fungus). Please see attached photos. One of the photos shows an older piece of fungus which certainly looks like Fomes Formentarius. The other photos show a newer growth nearby on higher branches which I think is also Fomes Fomentarius and I assume the upper surface will age over time and turn grey to give the hoof appearance.
I would be very grateful if you would kindly look at the attached photos and confirm whether you also think it maybe Fomes Fomentarius. Please feel free to use the photos for your own use if they are of assistance.
In addition, due to the age the tree has some lichen growth on it and I am anxious to save the tree. On the assumption that it is Fomes Formentarius I would be grateful if you would confirm:

Click on the photos for an enlarged image

1. Whether it should it be removed?

2. Whether a fungicidal spray or wash should be applied?

3. If it should be removed, do you sell any products and when should treatment be applied?

Please note that it appears that there will be a good crop of Greengages this year and it maybe that the fungus should be left until the Autumn.

I think the fungus on your greengage tree is actually Phellinus tuberculosus( http://fungifinder.arborhelp.com/Home/phellinus-tuberculosus. These two can look quite similar and are often confused. Fomes tends to like trees other than the cherry family, of which greengages are part. Phellinus tuberculosus loves appearing on the cherry family and often produces one fruiting body above another, sometimes fusing them together, even to the point of growing in resupinate form (appressed layer attached to the bark) at times. Fomes has a very distinct horse-hoofed shape fruiting body and also a distinct colour when mature, which is absent on these fungi pictures. Also the majority of the fungi showed in the photos are associated beneath old pruning wounds, which also is a characteristic of Phellinus.

The lichen is OK on a tree and can often be an indicator of air quality, but doesn't affect the tree at all.

With regard to what you can do about the fungus:

1. If you remove the fungus, you are only removing the fruiting body. The fruiting body is purely for reproduction (dissemination of it's spores) and doesn't degrade the wood. The fruiting body is formed when the mycelium detects changes in gases and UV light - these trigger changes in the mycelial cells and they start to form a fruiting body. The main part of the organism is actually within the wood itself and because of this, cannot be removed. The mycelium (which is the digesting and main part of the fungus), produces threadlike strands (hyphae) which break down the woody cell walls and then breaks down the contents of these cells. Because of this interaction at a cellular level, it is impossible to treat or remove.

2. There are chemicals that would kill some of the hyphae, but in using them, you would also kill off all the remaining live woody cells and another fungus would only colonise that dead material. Chemically treating the tree is not really an option.

3. The only management that you could employ to any effect, is to cut out all infected wood. However this may grossly distort the tree, or if the fungus is on the stem, be impracticable. In any case you would be creating nice big wound sites for the fungus to recolonise. Phellinus is not particularly fast acting and probably won't kill the tree, but in it's advanced stage, may likely cause structural failure of the infected part. The fungus is believed to be a soft rotter (i.e. it degrades the cellulose in certain parts of the woody cell wall) in early colonisation, but then moves into a white rot stage, in advance degradation.

I know you are fond of the tree, but you may want to consider propagating a cutting of it and planting it nearby. Hopefully, the tree will last until the new planting has established itself. I know that's probably not what you wanted to hear, but there isn't really anything that can be done to remove this fungus from the tree.