Bugs bite the dust on bitter pill.

Bugs bite the dust on bitter pill

Imagine a soft, gelatin capsule about the size of a vitamin pill, but filled with hundreds of microscopic, parasitic worms. The worms, a variety of nematode, are the "active ingredient' in a newly patented agricultural pest-control system. Although not yet commercially available, the "pills' have been shown in preliminary tests to be effective against such pests as fire ants, termites and corn rootworm.

It's been known for years that parasitic nematodes can be useful as biological controls. When consumed by an insect pest, the mematode releases a variety of bacteria that are deadly to the insect. But with 2 billion to 3 billion nematodes required per acre for control, distributing them is a problem. The new method "sort of puts them in a state of sleep' inside easily distributed gelatin capsules, according to Robert J. DeDominic of Plant Genetics, the Davis, Calif.-based biotechnology company that developed the system. He says the innovative delivery system has great potential "if we ever get people to start producing these nematodes in great enough quantities.'

Indeed, the friendly nematode is in short supply. According to Art Kushner, a vice president of Biosis, a Palo Alto, Calif. mass-producer of nematodes, it's difficult to grow nematodes in large quantities. The company is experimenting with growing them in a 7,500-liter fermentation container, with hopes of producing 100,000 nematodes per milliliter. However, he says, "we think we'll have to grow them at a density of 200,000 to 300,000 per milliliter to get competitive with chemical controls.'

He adds that partly dried, living nematodes may prove more useful than the gelatinized ones, as the latter need to be refrigerated. "Some people may have a problem sticking these in their refrigerator next to a piece of Jarlsberg cheese.'