"That we can get as many insects as we were getting tells us that this plant is not a bad host for these insects," he said.
Some adults emerged from the Miscanthus slightly earlier than they appeared on corn. More emerged slightly later than those on corn, Spencer said, but the timing of their emergence was close enough that "there's the possibility that adults coming off these two crops could interact."
This interaction could be good or bad for corn growers, Spencer said. If the rootworms that grow up on Miscanthus carry genes that make them susceptible to transgenic corn or to insecticides used on corn and they mate with rootworm beetles in a cornfield, it could help slow development of resistance to insecticides or transgenic corn among their offspring. On the other hand, the acres devoted to Miscanthus could function as a vast, perennial reservoir of rootworm beetles with devastating consequences for corn growers.
To determine if the western corn rootworm would lay its eggs in a Miscanthus field, the researchers placed potted Miscanthus plants in rows next to a cornfield during the egg-laying period. Late in the season, before the corn was harvested but after the rootworm adults were all dead, the researchers counted rootworm eggs in the soil around the corn and Miscanthus plants, and in the space between the rows of plants.
"There was no difference in the mean number of western corn rootworm eggs laid at the base of Miscanthus and maize in the field," the authors wrote.
The implications for corn growers are not yet known, "but these findings brought it home to us that much more study is needed," Spencer said. "Before we put something out in the environme
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign