[MikeHardman]

When spraying affected plants, I suggest having a look at wild ones nearby, too. They may be harbouring a population which is spreading to your cultivated ones - allowing reinfection after you have sprayed. I have noticed mealy bug on gorse bushes, for instance.

Yes, you could then say 'Where do I stop?', to which there is no precise answer. Obviously the greater the adjacent area you can spray, the greater the chances of stopping reinfection - but at greater cost and difficulty. Make up your own mind.

I confess I don't know the modes of transport of mealy bug. They are pretty sluggish creatures, but somehow they get around. If I knew, my suggestion above would be more confident; as it is, it is a tad tentative.
(I was suprised to find red spider mite on violets (V. biflora) in the Col de Gavarnie, on the north side of the Pyrenees, on plants that had only emerged from under the snow days beforehand. ...That is, not in a situation where the plants had been basking in a hot, dry, sunny spot for weeks. I mused that they could have been carried in the wind over the Pyrenean divide from the hot, dry, sunny southern side. I'm not suggesting mealy bug can use wind as a vector, just that it is not obvious how some things happen.)

[John]

I have to say that though they don't seem to move that much when you do see one on the crawl it can be quite quick, not much slower than a green fly, walking that is.

[MikeHardman]

Yes John, I can now concur, having seen a few at night when photographing moths at lights (where all sorts of other creatures also turn up): mealy bugs can move at a fast crawl.

[Daisy]

They certainly can move around.
In my garden, they have spread quickly throughout the garden.
I tried a number of organic sprays, but none of them worked at all.
Thanks to Jills suggestions, I tried acetimaprid. That didn't work either, but another of her suggestions, thiacloprid has.
Although by the time I found some in a local shop, a lot of damage had been done.



Border earlier this year, before the mealy bug.



Same border to-day after clearing the plants the mealy bug killed.



Anisodontea capensis El Rayo, an argaranthemum and some ivy leaved pelargoniums behind the pond, soon after planting.



The same area, after the mealy bugs.

Next year I would like to use neem oil.
It has proved impossible to find it here on Crete.
I can only find tiny quantities available on the internet.
If anyone knows of where I could find it in litre sized bottles, I would be most grateful.
Daisy

[Jill S]

Daisy, it must be heartbreaking, I had no idea the bug could be so devestating. Thank goodness something works but my heavens you have to catch it really early it seems.

Perhaps someone on here will know of a way to get a decent supply of Neem for you?! and then you can get in there first.
Jill

Have just had a look on Amazon and they have a 1000ml jar of it, should be able to supply to Crete, you could even get multiples and, as it is a systemic once absorbed by a plant, if you started really early you could gain a march on the little pests.

[Umbrian]

 :'(Daisy, I really feel for you, the devestation caused by these bugs is amazing and you must feel so helpless when nothing seems to deter them. I am sure you will win through though in the end and your garden will be as beautiful again as before. Good luck

[ritamax]

I am buying neem oil in Amazon.de (neemöl or niemöl in German). It is cheap in 1 litre bottles. It seems to work well if you spray regularly. You can put it around the stems pure to stop ants get to the plants (they supposedly do not go through that barrier.) I have put in addition neem pellets in the soil around the plants, mealybugs live also in the earth. They breed on weeds and many other host plants. Ants farm and protect them intensively. But I have to say, that on that side of the garden, where I have put the geotextile and the stone chippings, there are no pests whatsoever anymore. I gather or vacuum all the fallen leaves and do not leave any dead green waste lying around.     

[David Dickinson]

Don't know if they will deliver outside Italy but Neem Italia provide 1lt and 5lt quantities of neem oil. The following link is to the page for water soluble oil, in English. You can change the language in the top right hand corner. 

www.neemitalia.it/home/olio-di-neem-solubile


If they won't send abroad, I am happy to get you some and post it on to you. They have an outlet in Rome. Better to get it direct from them as commercial shipping costs are much lower than private postage.

Let me know

[David Bracey]

Here are two websites where you may be able to uy Neem oil.

http://www.cheminovaagro.com/products.htm

http://www.amazon.fr/s/?ie=UTF8&keywords=neem&tag=hydfrmsn-21&index=hpc&hvadid=492681321&ref=pd_sl_7b8bx2eck_p

Here is an extract taken from TMG no 63 page 45 "The female is wingless about 5mm (1/5in) long and forms immobile clusters on the pads where they pierce the epidermis with their proboscis and suck the plant juices. Fertilized females lay eggs which hatch into tiny active nymphs which then colonise new plants. Once settled, usually around the mother insect, they secrete a white cottony material which protects them from dessication and predators; this is the classical “mealy bug” which we have all seen. Males are smaller than females and have wings. They spread to new hosts on long waxy filaments blown by the wind. Multiple generations are produced in one year."

I remember my lecturer saying that males were spread by wind on gossamer threads.  (now there`s a thought).

I think it also worth mentioning that it is generally advisable with most insect pests to spray at least twice at 2 weekly intervals simply because insecticides may not kill all stages of the pest.  A second spray should kill any eggs which have hatched in the meantime.

Mealy bugs are particularly successful due to their protective covering.  Always add a drop (or two) or liquid detergent to your spray to ensure good wetting.

[Daisy]

Thank-you all so much for all your help and suggestions.
I saw ritamax's response first and have ordered  1 litre of Neem oil from Amazon.de.
I usually use Amazon.co.uk, but could only find it in small quantities on that site.
Thank-you David, for offering to post me some. That was kind of you.
And David, that information about the little *******, is fascinating.
Thank-you for the links. I think I am going to have an ongoing need for it, going by the evidence this year.
Daisy

[Jill S]

Daisy, (for future ref) if you go to amazon.co.uk and type neem oil 1000ml into the search box you will see that its available in that size for everything from 'health and beauty' to fending off horse fly under 'pet supplies', they even have it for horticultural purposes :0)) !!
I think now that they have got the taste for your plants you could be right about needing a continuous supply, do they have tribal memories?? 

[MikeHardman]

Some of my shrubs had a bad infestation of mealy bug, which I didn't notice until I pruned them. Doing so showed dark patches on the ground beneath where the branches had been. Here are two examples (Lantana montevidensis and Leucophyllum frutescens); the effect is clearer on the former.

The gravel doesn't matter; that can be turned over or replaced.
But does anybody have an idea how to remove the discolouration from the paving?

It does not come out at all with boiling water, as it would if the mould was growing on a simple sugary deposit as made by aphids. I suspect the deposit in this case may be waxy. And if I try burning it with a butane torch, I think I may make it worse (wax + carbon).

[JTh]

If it is  sandstone paving, you could maybe try chlorine?

[Alisdair]

Several determined squirts with a Karcher pressure hose should clear it - it did clear all but the worst lichen/black spot discoloration from our Indian sandstone paving in France.

[MikeHardman]

Thanks for the suggestions, Jorun and Alisdair.

Bad news: I can't comment on the effectiveness of chlorine or pressure spraying.
...because...
Good news: the first thing I tried was domestic bleach ('Domestos') - and that worked perfectly

I used it undiluted because: a) that was simpler, and b) being somewhat viscous, it stayed on the spot better (rather than running off). Within four hours, the dark mark had completely disappeared. The area is now indistinguishable from adjacent areas - that is, there was no bleaching of the colour of the sandstone, and no corrosion of the surface. With the proviso of being careful that excess does not run to plants/roots when/if it rains, I can recommend this method. On other (non-sandstone) surfaces, the outcome might be slightly different.