December 24, 2008
As the US starts to grow more corn for ethanol production, there are concerns that biological pest control may become more difficult.
A list of problems caused by turning more acreage to corn includes high prices for other crops, increased soil erosion and other negative effects, and now pest control has been added to it.
Increasing corn acreage can reduce the abundance of insect predators that control aphids, the most significant soy pest in the US, according to a report from Michigan State University.
An earlier study by researchers of fields in Iowa, Michigan, Minnesota and Wisconsin showed that landscape diversity around a soy field had great impact on the abundance of beetles and other insects that help to control aphids. The diversity is decreased as more nearby fields being turned over to corn production.
The study also calculated that corn acreage in the four states had increased up to 20 percent from 2006 to 2007, on the expense of soy crops.
The study estimated that in the four states, the cost to soy producers in lower yields and increased need for pesticides is nearly US$60 million per year.