Salento Diary (Xylella I)

Yesterday I attended a three-hour meeting of concerned organic olive growers from the Salento. They have been fighting, with some success, directives from regional, state and European authorities regarding how to deal with the alleged xylella crisis. I’m only beginning to sort this out (if indeed I am capable of doing that), but here is an initial read. Recent years have seen numbers of olive trees in the Salento afflicted with a rapid scorching syndrome. Local scientific and political opinion identified the bacteria xylella as the culprit and spittlebugs (Philaenus spumarius) as the vectors carrying the bacteria to the trees. Xylella, though present in North and South America, was apparently unknown in Europe before this. There are at least two theories as to the source of the presumed infection: plants imported from Costa Rica or xylella samples brought by US scientists to a 2010 workshop on xylella held in Bari (just north of the Salento). The latter of course suggests a catastrophic lapse in good scientific practices and the handling of pathogens. The proposed response to the problem was to eradicate the infected trees (including some of those 100s of years old ones), broadly apply insecticides to kill the (common) spittlebugs, and create a buffer zone (a clear cut) that would isolate the Salento from the rest of Europe. That strategy was reported in the press, and the tone of the stories I read (of which there were not many) implied that these were necessary measures to protect Europe’s valuable olive and grape industries. I am reminded of the malathion spraying in California in the 1980s – during the spraying as I recall we were advised to stay indoors - to eliminate the medfly that was destroying millions of dollars worth of California fruit crops. It is surely an accidental symmetry that Mediterranean fruit flies invaded California in the 1980s while it is possibly Californian xylella – the researchers mentioned above were from my alma mater UC Berkeley – now invading the Mediterranean Salento. In any case, as I have since discovered the story is not so straightforward as it first appears.