Scientists call “yellow rain” claim a lot of old bee faeces

Press, 13 April 1984, Page 21

Scientists call “yellow rain” claim a lot of old bee faeces

Two American scientists were strolling in a tropical forest in Thailand last month when, suddenly and without warning, they felt drops of “rain.” On closer inspection the drops turned out to be the sticky yellow faeces of honeybees, which were defecating on the two visitors from a great height — of about 50 feet. One of the scientists, Professor Matthew Meselson, a biochemist from Harvard, received a direct hit in the middle of the forehead with a gooey spot about three millimetres across. Professor Tom Seeley, a bee expert from Yale, was dealt a glancing blow with similar material on his spectacles. The downpour lasted five minutes in all and deposited about 200 spots per square metre on the men’s clothing and their Land Rover.

far that at least some of the “yellow rain,” which the Reagan Administration has charged is a form of chemical warfare the Soviets are using in South-east Asia, is, in fact, bee faeces. The Administration now faces a serious erosion of the credibility of its scientific evidence used to support that charge; and an unnamed State Department official has acknowledged, for the first time, that bees might account for some of the alleged samples of chemical warfare attacks — yellow spots on leaves and small stones — brought by refugees out of Laos and Kampuchea. Since last June, when Professor Meselson and a small group of colleagues, including the Sussex University chemical warfare expert, Julian Perry Robinson, and Professor Peter Ashton, of Harvard, a British expert on tropical

Strangely, this extraordinary bee performance is exactly what the two scientists had gone : ; Thailand to look for: where wl»u colonies of bees go on massive “cleansing flights. Their discovery provides the most impressive evidence so

PETER PRINGLE in Washington on discoveries by American scientists that the “yellow rain” thought to be a form of chemical warfare in South-east Asia was probably bee droppings.

flora, first floated the bee faeces hypothesis, Administration officials have scoffed at the idea. Even today they say it stretches the imagination to believe that bee defecation flights are relevant. Yet, increasingly, the problem of relevance seems to be with the United States Government’s scientific evidence rather than with the hypotheses put up by other scientists. In 1981, the United States claimed it had the first physical evidence of the use of chemical warfare in Kampuchea — a leaf and a stem containing mycotoxins, the poisonous product of a fungus called fusarium. The allegation against the Soviets was that they had supplied the toxin to their client state Vietnam, thus violating two international treaties banning such weapons. The precision of the

Journal,” vigorously opposed it. Why would a scientist bother to test hypotheses about fact that was already (in the newspaper’s view) well known and accepted? However, the sceptical Professor Meselson continued to gather evidence that suggested a natural explanation — bee faeces for the toxin. A relatively obscure technical magazine, “Chemical and Engineering News,” journal of the American Chemical Society, was the only publication to follow his findings at any length. If the pollen in the samples brought out by the refugees was not bee faeces, could it be, as the Government first suggested, a cunning mixture of specially-collected (as opposed to bee-collected) pollen?

United States Government’s charge and the shrillness of its claims — including affirmation by President Reagan himself — scored many propaganda points. The fact that many of the environmental samples contained pollen suggested to Professors Meselson and Robinson that the United States Government had been mistaken and that the source was natural — bee faeces which are made up mostly of pollen. Although Professor Meselson had served four previous governments as a scientific consultant, the Reagan Administration did not seek his advice on yellow rain. Because it presented such a challenge to scientific detection, Professor Meselson set up his own private inquiry. The American press faithfully reported his progress and in some instances, notably the “Wall Street

Professor Meselson now says that the discovery of the bees’ cleansing flights “removes the last obstacle, as far as we can see, to concluding that ‘yellow rain’ is not a weapon of war. It is, in fact, the defecation of wild honeybees.” — Copyright, London Observer Service.