An army of insects could soon come marching through your back yard, munching on your morning glory and eating enemy No. 1 — Utah's proliferation of noxious weeds.

The vision of a million little mandibles grinding those poisonous plants to nonexistence is not just a dream, it's a scientific reality that's been at work in Utah for the past 60 years. Biological control agents — bugs — are being brought in from across the world to feed on plants from their kindred country that are wreaking havoc in the United States.

In their native countries, leafy spurge, spotted knapweed and yellowstar thistle — some of Utah's most problematic plants — are gentle weeds that are kept in check by their natural predators, little insects that feast on their foliage and root systems. But in Utah, an ocean away from their predators, the non-native plants, which can paralyze horses and poison cattle, run rampant without any control.

"Usually, when you take (noxious weeds) out of their habitat, you take their natural enemies away and the plants get very aggressive," Utah County weed coordinator Craig Serle said. "There are probably insects (in Utah) that feed on the plants, but not to the point where they cause enough damage to keep them in check. (Biocontrol agents) seem to be very specific in controlling (individual) plants."

Serle has released biocontrol agents in Utah County several times over the past seven or eight years, targeting dalmatian toadflax, bindweed, Canada thistle, musk thistle and other weeds. The weeds have not been the most prolific in the area, but those are the plants for which biocontrol agents have been available.

Some agent insects can be collected from local "insectaries" where the bugs' population has been cultivated, but when time is of the essence, the bugs are mail-ordered from a catalog.

There are 19 different kinds of biological control agents that can be shipped on ice, overnight, from www.bio-control.com, which is just one business out of a whole industry of bug suppliers.

Leona Poritz, who manages www.bio-control.com and co-owns Biological Control of Weeds Inc. with her entomologist husband, Noah, sells bugs to Serle and others like him who oversee large areas of land. But Poritz doesn't sell bugs are meant for a residential situation.

Strict U.S. Department of Agriculture regulations apply to biocontrol methods. Permits must be acquired before biological agents can be purchased, and the agents themselves are rigorously studied before they are ever released on American soil.

Insects are kept in greenhouse quarantines for at least three years when they first arrive in the United States. During that time, the bugs are placed on the leaves of other plants to see if the agents can live on any plant other than the host weed. If the bugs fail by starting to feed, they are rejected from the testing process and barred from entering the country.