SPIDERMITE
By peonyrose
10 comments
I had posted a Question re. my ailing Plum tree and included some photos which show the mite and the webbing. Since then, on investigation, I have discovered the culprit and thought you all may be interested…just incase any of your fruit trees ever show the signs of infestation. All fruit trees can suffer and these little blighters can move around by being blown in the wind…………………..
Two-Spotted Spider Mites (TSSM) Biology
TSSM is a pest of many crops. TSSM is pale green or straw-colored and easily distinguished from ERM by two dark spots on the back.
Spider mites are not insects but are more closely related to ticks and spiders.
Their common name is derived from their ability to produce silk, which most species spin on host plants. These mites construct a characteristic webbing on the undersurface of the leaves, strands of webbing are spun by the mites on the undersides of infested leaves.
Prolonged, heavy infestations cause yellowing or bronzing of the foliage and premature leaf drop similar to drought stress.
Females become active in the spring as temperatures warm, and they begin rapidly depositing eggs on the undersides of leaves. Eggs hatch in 4 to 5 days and the entire life cycle from egg to adult may require 1 to 3 weeks. A female mite lays 70-100 eggs.
The minute, spherical, translucent eggs, about 0.1 mm in diameter, are usually laid amongst webbing.
Nymphs (young stages) vary in coloration, but are normally pale yellow, pale green, or straw-coloured.
The first nymphal stage (larva) is six-legged, whereas the later protonymph and deutonymph stages are eight-legged.
The juices which the mites obtain from stressed plants are rich in nutrients and the mites multiply extremely quickly.
There are 3 to 5 generations each year.
TSSM overwinter as adults under bark or on weeds beneath the tree and often build up on broadleaf weeds, brambles and sucker growth beneath the tree in the spring.
Although TSSM can overwinter successfully on trees, large numbers often migrate into the tree canopy or overwinter as adult females in the soil.
The safest product to use which only kills nuisance insects when applied is INSECTICIDAL SOAP.
If you want something a little stronger, you should apply PERMETHRIN CONCENTRATE. This product will last 7-14 days providing a mild residual so that there is something left behind to kill off rogue mites which are missed with the first spraying. It is both odorless and very effective
on just about any pest and is probably the single most used insecticide on vegetable and fruit plants in the world.
12 AUGUST: I’m delighted to say my plum tree has remained healthy and is heavy with fruit.
- 11 Jun, 2010
- 1 like
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Comments
I would not use the synthetic insecticide Permethrin as I consider it dangerous to humans (carcenogenic?) and wildlife such as Honeybees as Permethrin is released into the environment when used in agricultural areas. There are no natural sources of Permethrin, although related natural 'Pyrethroids are found in some plants.
11 Jun, 2010
Thanks Drc. Since reading more about Permethrin it appears it is toxic to cats and can be fatal. I am going to wash this tree just now as a first step and will speak to my local garden centre and see what they would use.
11 Jun, 2010
great
11 Jun, 2010
Well I spoke to an expert at the gardening centre who knows about TSSM, but the news was not good. Nothing seems to get rid of it! He and a colleague said I could try de-foliating the tree - Huh?
The only other suggestion was to try biological control, which I would have to source on the internet-and apparently it's very pricey.
Meantime I jet washed it ( I got soaked to the skin) for 30 mins and spent the afternoon picking off leaves which had webbing or mites on. I also found small green caterpillars which are obviously responsible for the chewed leaves. I will do this daily until I make more enquiries about a suitable control.
11 Jun, 2010
Oh I do hope you can stop it.
11 Jun, 2010
Update on my plum tree is that it has survived and no sign of spidermite or caterpillars! I continued to jet wash it daily and with that, and our cold weather, I think they had had enough. It looks like we are going to have a good crop too.
10 Jul, 2010
That great Peonyrose
10 Jul, 2010
Thanks - and by the way I love all your Gazanias. I must try some next year.
11 Jul, 2010
thanks - yes you must they are lovely
11 Jul, 2010
Very Interesting Not seen those around ,don't want to either.Thanks for information
11 Jun, 2010