Prickly Pears, Cocheneal Flies and What We All Should Know.

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Prickly pear Cactus while we might consider them exotic, pretty even, are a menace which is spreading in Malaga and Almeria provinces. Originally bought to europe in the 1800´s from central America fo the production of vegetabe dyes (Cochaneal fly) they now represent one of our most invasive species. Anyone living in rural areas of Andalucia this year will have not missed the small white flies that have been flying right through our mosquito netting and dying in their thousands in our homes. They are attracted to our lights and pools. Once on furniture and bedclothes for instance you will have permanent staining from the blue red dye they harbour in ther bodies.

In Almeria province this problem has been well publicised by the authorities but in other areas of Spain it has not. I feel that by word of mouth people should spread awarness of the problems that these cactus pose as both an invasive species and their hosting of the Cocheneal fly colonies.
What to do?
1)Dont plant them to start with.
2)If you have them cut down and bury the cactus. If they dont have light they will rot but they need to be felled and covered with earth.
3)There is liquid available from garden centers that can be sprayed on the plant which breaks down the skin so that the mosture is lost and the cactus `deflates´ and will dry and die but it will need a few aplications over the year and before the summer heat.
4)Try to uproot smaller plants with a pickaxe. The root systems are usually close to the surface and are often easy to pull up. Let them dry out and burn them when you light your next fire, that will at least disable them.
5)If you have a lot work away at them over a couple of years.
6)Tell your neighbours to do the same.

What not to do.
1) break off parts of the cactus and discard them in the campo. They will always grow, wherever and in two years you will have a big job where before you had a small one!
2)Ignore them. They spread and as we have seen the resulting white flies are not easy to live with.

Really, this is a serious long term problem that is only going to get worse without concerted effort.

Any comments or sugestions welcome . Thanks.

[kevsboredagain]

I have a huge one in our garden but not had any problems with flies. On my next trip I need to reduce it in size again as it hangs out over a wall and the weight could make it dangerous.

It's not a nice job keeping it contained but I've certainly not felt the need to get rid of it completely. The flowers each year are very impressive.

I do however have a problem with an American Aloe which reach an enormous size and has now flowered. The flower stalk is the size of a tree and the whole plant has now died. Not looking forward to cutting all that up either.

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You are lucky not to have the fly problem yet. Containment and control is key. They spread by dropping the big heavy leaves in high winds etc and then they just take root. Whatch out for any white fluffy patches on the Cactus. This is the sign of the Cocheneal fly. They will also affect many other plants but the cactus is their favourite.

[costa-brava]

KEVSBORED
Your American Aloe sounds like the plant they call "pita" here. There are hundreds around the town and one little bay is actually called "Els Pites" in Catalan. The long stem makes a lovely Christmas tree so don't be too quick to cut it down. As far as I know the plant lives for 10-12 years then produces one enormous stem then dies.
Like you we have lots of the prickly pear cactus around and so for no messy white flies.

[kevsboredagain]

KEVSBORED
Your American Aloe sounds like the plant they call "pita" here. There are hundreds around the town and one little bay is actually called "Els Pites" in Catalan. The long stem makes a lovely Christmas tree so don't be too quick to cut it down. As far as I know the plant lives for 10-12 years then produces one enormous stem then dies.

It started making the flower stem in May and I thought there was an extra electric pole in the garden! Now it's about 50 feet high and could bring down the power line if it falls. The plant itself is now dead so it will be a massive job for me to remove it piece by piece.

Whenever I have to work on these big cacti I get small infections from being stabbed by the spines. Nasty work.

[Casscat]

*note to self:must look up this cactus*. My garden is full of cacti but I am not aware of this infestation problem

[cleanforum]

The white fly infestations seem to be moving along the coast. My own Finca is 5km inland and I have noticed this white fly on cactus up to 10km inland. It may be that they need a certain humidity to thrive. Perhaps someone knows the answer to that. It is true that this year we have had a very humid (and hot of course) summer.

It seems they have only one natural predator the ladybird of which we see very few.

[lorca]

Here in Malaga Province (where the plant is known as Chumbo) the problem is serious. The plants are not considered a "menace", but are in fact extremely important in helping to bind the soil on the very steep slopes on which we and our neighbours farm.

The small farmers' associations have asked for help from the regional government to help deal with the infestation.

[CSE]

Do not know if this will help anyone.
http://spanishnewstoday.com/the-cochini ... ZFr7Ua20qg
Thankfully none of this up here.

[cleanforum]

Interesting article, although I disagree that the flies kill the cactus.

This is just plain wrong. I have yet to see a single one dissapear due to this fly. As long as they leave just a few leaves (or parts there of) the plant just regrows.