Although this article mainly concerns Lanjarón, evidence of this prickly-pear disease is all over Andalucia: shrivelled cacti pads covered in a white substance.
The local branch of the PSOE inspected the chumberas in Río de Lanjarón and found them seriously affected… they also took the opportunity to criticise the PP Mayor for not responding to the situation. You can blame the PP for many things, but the state of prickly pears is not one of them.
The Spokesman for the socialists reported that “the damage is immense and is spreading in other areas very rapidly,” thus demanding that Town Council “intervenes immediately” because the affected area is where one of the most important touristic routes runs, serving as the entrance to the Parque Natural de Sierra Nevada.
The plague is caused by the Cochinilla del Carmín (Dactylopius Opuntiae), which is an insect that devastates the cacti by sucking out the sap and leaving them completely dried out, hence their alarming appearance.
The insect is native to tropical and subtropical South America as well as Mexico and Arizona, it lives on cacti, feeding on plant moisture and nutrients. These insects are found on the pads of prickly pear cacti.
If you have chumberas and the infection’s just beginning, you can rub down the flat branches or pads of the cactus with soapy water using a brush – careful with the spines, obviously.
If the nasty little critters have got a good hold on your chumberas (sounds painful) there is no other course other than to amputate the affected pads and bury them. What you do not do is pull the chumberas out by the roots and you certainly don’t throw the infected pads anywhere near garden refuse.
An infected plant gives off a nasty smell of rot, which attracts flies and mosquitoes. People mistakenly believe that the mosquitoes are the cause, whereas in reality, they are only a consequence of the infection.
However, the diminutive males of the chochinilla are white and are airborne at certain times of the life cycles of this pest.
If your chumberas are badly affected then you must amputate all the affected sections, even if they are only 25% covered with the disease, If you can get a hose with a good pressure on it, wash off what is left of the remaining cactus plant. The female bug only eats this kind of cactus and once washed off will fall to the ground and perish. They are not attracted to the almost wooden trunks of the plant.
Once it is well washed off, you can use an insecticide called Azadiractina, which has a low toxic value. There is also another new product, which is completely ecological (made from algae) Agritrap, which covers the plant in a thin membrane that suffocates the pest.
This article does not mean to be conclusive or definitive but merely ‘orientating.’ Consult a specialist and mention the two insecticides and see what they think.
(News: Lanjaron, Alpujarra, Granada, Andalucia)