In their experiments, the fungus killed the adult insects within two to four weeks after infecting them. But the fungus doesn't grow on the stored grain and is harmless to humans and animals. For tests, scientists incorporated the fungus into a powder. They then mixed the powder with brown and long-grain rice in containers simulating storage bins. Next they released adult insects into the containers for up to 21 days.
Scientists caution further research is needed, particularly to find how it can be formulated.
Ideally, Beauveria could be deployed to squelch the first infestation of adult insects. This would greatly reduce numbers of a succeeding generation of wormlike offspring. A natural fungus could even the odds against common cocklebur, a tall, bushy weed that bullies smaller soybean plants in competing for sunlight and nutrients. Many herbicides don't control cocklebur infestations, which can cause soybean yield losses of up to 80 percent. ARS scientists hope to curb its destruction with the fungus Alternaria helianthi .