Forum home Problem solving

woolly aphid on crab apple tree

Have had my crab apple tree for about 10 years. Woolly aphid appeared 2 summer's ago. they are disfigering the branches and seem to over winter on the tree. Is that possible? They make a mess of the plants underneath. I don't use pesticides, has anyone got any suggestions of how to deal with them. I hose them off regularly but the always come back. Thank you.


  • PalustrisPalustris Posts: 4,304

    They are a real nuisance. Try using a Horticultural soft soap. This is made from plant material and is reasonably organic.

  • Here in Toronto Ont chemical insecticide,chemical herbacide,and chemical funguside is banned,so we are compelled to use horticultural soap ect,We now have more bugs,weeds and fungus than ever before. The soap dosn't kill bugs it just makes them nice and clean.


  • DovefromaboveDovefromabove Posts: 87,935

    The long-tailed tits love the woolly apids - shame there aren't more of them about (tits, not apids).image

    Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.

  • PalustrisPalustris Posts: 4,304

    Used properly the soap (indeed any soap)  will remove the waxy coating (the woolly bit) from the insect and then a good spray with a power washer (set so it does not damage the bark), will drown the blighters. You may have to repeat the treatment, but it does work, or at least it worked for us.

  • These are a real nuisance, I have them on a blackthorn hedge, it's made such a mess of it, I am considering replacing it (although I am loath to do so, as it's home to nesting sparrows every spring).  I have been advised that the organic way to do it is use pyrethrum spray (made from peppers, I believe), to try to control the infestation, and then keep it under control with ladybirds (the larvae apparently love ANY kind of aphid).  It hasn't got rid of them completely, but it's better than it was last year.

    We don't have any kind of tits in the garden - the sparrows and the very territorial blackbird chase them away, I was very excited to see a blue tit on my bird feeder the other day, until the sparrows ganged up on him.  They nest in the hedge, but don't do me the favour of eating the damn things!

  • PalustrisPalustris Posts: 4,304

    The trouble with any insecticide is that the coating on the aphids is waterproof and stops the stuff from  reaching the actual bug.. Lynda did say she does not use pesticides so Pyrthrum based sprays would not be her preferred option.  And sorry to harp on about it, but Pythrethroids are extremely toxic to bees.

    If the infestation is small you can dab each aphid with a cotton bud dipped in Methylated spirits. That kills them.

  • Berghill, I only recommended pyrethrum as I had it recommended to me by a company that sells organic products, I was under the impression that pyrethrum was made from peppers and therefore safe to use.  If it is toxic to bees, why is it being marketed by a company that is supposedly organic?  If it has the same properties as the neonicotinoids, I won't be using it any more, can you suggest something I can use on it that IS safe for bees?  Whenever I apply any insecticide, I always do it at dusk, when most of the pollinators aren't out, I know that neonicotinoids make the entire plant toxic, so don't buy anything that has it in (generally anything that ends in 'cloprid').

    Basically, can anyone recommend an insecticide that WON'T harm bees?

  • PalustrisPalustris Posts: 4,304

    Pyrethrum IS safe in that it is not persistent in the way neonicotinoids seem to be. And as you say, spraying once the bees and hover lfies have gone to bed is the best option (IMHO).

    Pyrethrum is actually made from the roots of the plant of the same name, Pyrethrum which is a white daisy.

    Pyrethrin insecticide effects on bees and beneficial agricultural insects & Fish & Cats


    Pyrethrins are “highly toxic” to bees; 0.02 micrograms is sufficient to kill a bee.50 Toxicity of commercial pyrethrin products to bees was demonstrated by an entomologist at Auburn University who showed that a commercial pyrethrin insecticide caused 100 percent “knockdown,” the inability of the bee to walk or fly. Some of the inert ingredients used in pyrethrin products appear to increase knockdown potency.51 


    It is not surprising that pyrethrins, because they are insecticides, are toxic to agriculturally useful insects and spiders. The International Organization for Biological Control found that a commercial pyrethrin product killed over 99 percent of two parasitoid wasps and a predatory fly. (Parasitoids are insects which develop in and kill the eggs or larvae of another species.) This study also found pyrethrins caused 80 percent mortality of two other parasitoid species, a fly and a wasp.52 Cornell University Agricultural Experiment Station researchers found that pyrethrins killed four common species of wasp that are parasitoids of house and stable flies in dairies.53  Another study found that Both the pyrethrin products tested led to 100% mortality in the adult parasitic wasps and ladybird larvae on glass plates and plants.

    I  cannot really help with advice on really safe pesticides as we do not use them. The only spray of that kind which I do use is a Horticultural soft soap one specially made for fruit trees and then that is sprayed on in February when there tend be very few insects around. It kills the eggs of Apple pests on the trees.

    It is not easy! Today I found a whole frame full of Alliums of various ornamental types, all with aphids on them. It took me ages to wipe then off with a damp cloth.

  • Busybee29Busybee29 Posts: 17

    We had the same problem last year and tried everything from chemicals, soapy water and pressure washing it. In the end we decided to remove it completely. It was at least  8 years old and had been lopped. It began to excrete a sticky white powder which damaged other plants. Best plan, remove and plant something else.

  • Lynda TLynda T Posts: 7

    Thanks for the advice. I have 2 blue tits that sometime eat them, but I think I need a whole flock. I will try the soap and see how it goes.

Sign In or Register to comment.