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From VOA Learning English, this is the Science Report.
A new study says a widely-used insecticide is damaging wild bee populations. Wild bees are important because they pollinate crops and wild plants. Environmentalists in the United States and
Europe say chemicals called neonicotinoids are causing a drop in the number of bees. These insecticides are among the most commonly-used worldwide for killing insects that eat crops. Farmers often use seeds treated with the insecticides. They get into pollen and nectar, which is where the bees come into contact with them. Maj Rudlof is the researcher at Lund University in Sweden who led the study. Her team studied bees in fields. Half of the fields were grown from seeds treated with neonicotinoids. The other half was grown with untreated seeds. Ms. Rudlof spoke about the study in a video for the journal Nature. She said they found that the bumblebee colonies almost did not grow at all in the treated areas. She says there were about half as many wild bees in treated fields as in untreated ones. Dennis vanEngelsdorp is a scientist who studies insects at the University of Maryland. He was not involved with the research. But, he said that banning the chemicals might force farmers to use products that may be either just as bad, or worse. He said farmers often use the chemicals too much, and that may be hurting bees. Mr. vanEngelsdorp said the chemicals should be used only when necessary. A United States Department of Agriculture report included information about the effects of neonicotinoids. It said the chemicals make the bees sick. So they cannot fight the viruses that commonly affect them.