Spraying The Caterpillars

Those of us who live on Mallorca or who visit the island in the late winter will be only too well aware of the processionary caterpillar. We look up at pine trees and see the nests, we look down and see the trails of caterpillars marching in connected formation in search of soil in which they can bury themselves, pupate and start the whole cycle of moth to caterpillar all over again. We are only too well aware of the skin irritations the caterpillars can cause or of the deaths of pets which might take too great an interest in them. We may be less aware of the harm that the larvae cause to pine trees and other conifer species. They can severely defoliate the trees, thus weakening them and leaving them prone to attack by other pests, by diseases or by environmental conditions.

There are an awful lot of pine trees on Mallorca, and so there are an awful lot of caterpillars. There are ways and means of tackling the pest, but one means - that of chemical spraying - has come in for severe criticism. The regional government's environment ministry is to undertake widespread spraying from the air during this month and during November.

The chemical that will be used is the diflubenzuron pesticide, known also by its brand name, Dimilin. This is a pesticide whose use has proved controversial and not just in the Balearics. For example, in the US state of New Jersey in 2007 environmental groups managed to overturn a decision by the state's department of agriculture to use Dimilin to tackle what was an emergency brought about by a sudden rise in the gypsy moth population. For over twenty years, New Jersey had used a biological pesticide called Bacillus thuringiensis (B.t.). The agriculture department considered this to be inadequate in tackling the emergency, despite the department itself admitting that B.t. afforded good protection for foliage and other species and for control of the gypsy moth population.

Opposition to the use of Dimilin was based on different factors. One, it was unclear whether it would in fact be any more effective than B.t. Two, it could kill other insects. Three, it could have a harmful effect on bird life. Four, it could introduce toxicity for water life. Five, one of its elements was, in all probability, a class B2 human carcinogen. Six, Dimilin was also a hormone disruptor that could harmfully affect both human and animal endocrine systems, in other words the way in which hormones are secreted into the body's circulatory system.

In New Jersey they had stopped using a different pesticide in 1985 because of its potentially harmful human effects. In Mallorca the use of Dimilin was banned by the first Antich PSOE-led government of 1999-2003. It hasn't been used in Mallorca since. Instead, the biological pesticide B.t. has been used. Now, the regional government is changing tack, and there is an outcry from environmental groups and certain political parties.

According to a spokesperson for the Més political grouping, the so-called "Company campaign" (named after the minister for both the environment and agriculture) will, through the use of Dimilin, be more expensive than alternatives and have a greater environmental impact. The cost of the spraying, some two million euros, has not been budgeted for, leading to questions over the awarding of a contract for the spraying. The environmentalist group GOB has attacked the use of Dimilin, noting a regional environmental sustainability report which says that it is not recommended for large-scale spraying on account of its indiscriminate effects; the government plans to spray more than 24,000 hectares of pine forest on Mallorca.

GOB has submitted a written report to the European Commission, drawing attention to a possible breach of a directive on the conservation of natural habitats and flora and fauna and to the regional government environment ministry going against its own sustainability report. GOB notes that the directive requires there to be an impact assessment of the use of pesticides. It further notes that there has been no such impact assessment in respect of Mallorca or indeed the other three Balearic Islands, where pine forests will also be sprayed.

The university in Palma has entered the controversy by concluding that Dimilin does not affect other insects, while it has been noted that there was limited use of Dimilin in Ibiza in 2010, permission for this having been given by the then environment minister, Gabriel Vicens, a member of the PSM Mallorcan socialists, who are part of what is now the Més grouping.

So, what do we conclude? Are Dimilin's potentially harmful effects being exaggerated? In New Jersey it seems they took them seriously enough. In Mallorca, however, they are deemed less serious. And who would bet against there being the trails of caterpillars next March, Dimilin or no Dimilin?

Photo: http://mallorcaphotoblog.com/2011/03/08/the-processionary-caterpillar/

MALLORCA TODAY - Lack of funds to tackle processionary caterpillars

The processionary caterpillar, which attacks pine trees across Mallorca and which poses a health risk to humans and animals, is liable to be less controlled than previously owing to a sharp reduction in funds available to the local forestry authority. Typically the moth and caterpillar have been tackled by placing traps in forests to capture the moths and then spraying to kill off the caterpillars in the trees.

When Mama Was Moth

Just a word about the weather. Yesterday was truly magnificent. It is a surprise that January can produce such fine weather, but it does, and pretty much every year it serves it up. Warm and sunny (around 18), the holiday walk along the beach should have been done in shorts and flip-flops not jeans and trainers with socks; it raised a fair old sweat. The sea was flat calm and the sand firm, an indication of a lack of recent wave turbulence. Absolutely blissful.

Less blissful though is one of the natural-world’s irritants that raises its ugly head, well ugly body, at this time of the year. The processionary caterpillar* is a creature of southern and central Europe though it is migrating north. It is a thoroughly unpleasant bit of insect life that offers a dual malevolence – to trees and to humans. It is during the first couple of months of the year that it becomes a real pest.
(*So-called as colonies of individual caterpillars attach themselves to the ones in the front.)

The deal with this caterpillar is that it is moth larva, spawned by the moth that those bags you might see hanging around in forests are there to catch. The moths need to be taken off the streets – as it were – to stop them producing the caterpillars. Not only do the caterpillars cause great harm to pine trees, they also have a nasty habit of falling out of the trees and poisoning passing humans. If you happen to see any army of brown, furry-looking caterpillars forming a caravan, on no account touch them. One of the best treatments for them – gruesome though it may sound – is to set fire to them. The devastation that the caterpillar can cause to trees (and the oak is also susceptible to a different caterpillar) is akin to that wreaked by the beetle responsible for the fungus of Dutch elm disease. The poison emitted can cause serious skin reactions.

Avoiding the little buggers is a bit tricky. Go for a walk in a forested area here (or indeed just down many a road), and there will be numerous pine trees ready to dispatch the caterpillars. Daft though it might sound, a hat and keeping skin covered up is a wise precaution if walking in forests in January and February. Don’t hug a hoodie, wear one.

One way of trying to short-circuit the problems they cause is to shoot them down (and then deal with them), and this does indeed happen, so if you hear gun shots going off, it could well be a whole bunch of caterpillars – a sort of land-based equivalent of jellyfish – being blasted.

Apparently, there is also meant to be some spraying going on to kill the caterpillars. If this is from the air, which I understand it is, then a question is why not do this for the mosquitoes? A reason for stopping that spraying was the ecological impact. There again, mosquitoes don’t harm trees. Something’s wrong here I feel.


QUIZ
Yesterday – CCS (Alexis Korner). Today’s title – real personal indulgence here; one of my “favourites” from my profile did this.

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