Ugly bugs

I noticed brown patches on the leaves of a hibiscus in the greenhouse, looking at the underside of the leaves I found these ooh nasties.

Any idea as to what they are?

 

Looks like one of the many scale insects. Some are specific to particular species of plants but others are pretty omniverous.

Sprays aren't very effective as the wee beasties have a waxy protective coating. Carefully rubbing each leaf between finger and thumb is the best way to deal with them if they are on a single plant. Sprays are only usefull at the 'crawler' stage of their development.

 

I've a vague recollection about cotton wool and meths being used to shift them. I could well be wrong though and it might apply to another bug.

 

I think scale is the up and coming pest, it is as far as I'm concerned.
I'm getting more and more of it these days and it can be difficult to find, it saps the plants strength and leaves loads of sooty mould, which is often the only give away that its there.
I've not really gone into it but I think the biological control for it is expensive.

Not sure Dave but I think the meths trick is for mealy bugs.

 

You could also try keeping the following in or near your greenhouse:

6 inch pot planted with garlic;
marigolds
toads

 

I have this problem too, at the moment have scale insect on our lemon tree and bay tree. The bay tree was so bad some months ago that I almost massacared it to get rid of the worst. If it isn't too bad I've always done as frogesque does.

I think I will try your tips of garlic and marigolds linlin. Have you yourself had luck with these methods?

 

Yes Pete - You're right!! Thanks for jogging my lamentable memory. :rolleyes:

 

Hi Rich, with scale insects you need to use a systemic insecticide this will kill them and you can then just rub them of. David.

 

Hi guys. I used to suffer from this on my Camellia. I was abit stuck after they banned Malathion so now I use Provado bug killer ( a systemic insecticide). It works a treat although some times you have to spray again after a fortnight. All the best.

 

Hi I found scale insect for the first time the other day on my Aralia elata, they were'nt on the leaf but the trunk, I knocked them all off but I better spray too had'nt I? :(

 

Rich, they look like the same 'bug' that I found on some bougainvillea brought back from abroad, even under a magnifying glass they were hard to identify. I don't think it is mealy bug. I had scale on my holly which was there when I bought it, probably imported from Italy ... seems to be lots of new alien bugs coming in. :(

 

I think scale insect is going to be THE pest of the future, I seem to have nearly as much trouble from it as I do red spider.
Give me good old greenfly any day. :D

 

I have found these pests mainly on the stems of bushes. I got rid of them by wiping the affected bits wth white spirit on cotton wool or kitchen roll. Luckily my plants weren't too big, and the leaves not affected. I did this a couple of times during the summer and the beginning of the next year, and then they seemed to disappear.
I'm sure it doesn't do the plants much good, but then neither does a heavy infestation of scale insects.

 

Rich there's a link hear to the rhs site tells you all about your problem
http://www.rhs.org.uk/advice/profiles0801/scale.asp