The US Center for Food Safety has released a report on the effect of herbicide resistant genetically engineered crops on the monarch butterfly population. Over the past 20 years, the number of butterflies has plummeted 90%. The culprit is the Monsanto company's herbicide glyphosate that is being sprayed on genetically engineered, herbicide-resistant corn and soybeans, known as Roundup Ready crops. It is killing the monarch butterfly’s habitat and milkweed, the caterpillar’s main food source. teleSUR