It sounds like a horror movie: 720,000 ladybugs on the attack in Manhattan.

In this real life story, however, the red-and-black bugs have been unleashed on the 80-acre grounds of one of New York's biggest apartment complexes with a mission: eat pests infesting the neatly landscaped property.

The ladybugs from Bozeman, Mont., arrived at the Stuyvesant Town and Peter Cooper Village complex on Manhattan's East Side on Thursday afternoon, packed in boxes shipped by a natural gardening company.

From mesh bags filled with wood shavings, groundskeepers scattered them in clusters of 72,000 per box. The ladybugs quickly took to the skies of the 80-acre rental complex.

In the next days and weeks, they will crawl into plants, flowers and shrubs in search of insects whose smell attracts them _ soft-bodied, leaf-sucking aphids and mites.

Buying the bugs means the complex's owner, Tishman Speyer, can avoid using chemical insecticides.

"In most cases, we reach for a can of pesticide _ and we kill not only the 'bad guys,' but the 'good guys,'" said Eric Vinje, owner of Planet Natural, which supplied the pest-killers for Manhattan.

"All we're doing here is putting more of the 'good guys' to tip the scale," he said.

On its Web site, the company offers "Live Ladybugs _ Free Shipping!" at $16.50 for 2,000.

This species of ladybug _ Hippodamia convergens _ converges in the wilderness, where they are harvested.

Vinje buys them from ladybug collectors working the foothills of the Sierra Nevada mountains in Oregon, California and Montana.

In Bozeman, he keeps them alive in large refrigerators where the temperature is kept to about 35 degrees.

They go "dormant" at that temperature, using up their fat stores without eating anything, and staying alive for about five months, Vinje said.

In the shipping boxes, they slowly awaken while flying to a buyer's destination. By the time they reached Manhattan, "they were lively and ready to eat anything that was not too quick for them," Vinje said.

Vinje said 720,000 ladybugs are about the right number to clean up the New York complex.

Each insect can take care of a piece of land measuring about 19-by-19-inches. A ladybug can eat up to 50 pests a day, plus insect eggs. The huge colony will consume billions of pests before moving on.

Apartment residents need not worry about confronting swarms of ladybugs, since this is not the Asian ladybug typically spotted in urban areas. "This one is not prone to entering homes," Vinje said.

Plus, if one buys into a common superstition, the 720,000 ladybugs should bring a torrent of good luck.