Bacteria May Hold Answer For CPB

Published online: Jul 22, 2003
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Agriculture Research Service scientists may have found an answer for control of the difficult-to-handle Colorado potato beetle.

It has been found that the purple bacterium, Chromobacterium suttsuga, kills the CPB in laboratory studies. But before applying the bacterium to the soil, they need to know how long it survives, if it changes the soil, or if it's harming the environment or other beneficial organisms.

ARS researchers at the Insect Biocontrol Lab in Beltsville, MD, adapted a technique to detect C. suttsuga in the soil. Microbiologist Phyllis Martin and her colleagues found that by using sterile rice grains, she could detect small amounts of the purple bacteria-fewer than 50 cell in about a teaspoon of soil.

Rice grains were placed on moist soil. In about three days, some rice grains turn purple if C. suttsuga is present.

The tests prove to be sensitive as more expensive methods that depend on copying DNA. It has the advantage of simultaneously detecting, quantifying and determining that the bacteria are alive.