The present invention provides for the first time a biological system which provides the dual function of killing termites and other wood damaging insects while also producing a by-product substance having the capability of repairing damage by termites and other insects to wood and related cellulosic products.The present invention, a biological system, toxic to termites, is provided which produces a means by which damage caused by termites is repaired, said means comprising a by-product produced by a modification of the bacteria of the genus Gluconacetobacter. Preferably, the biological system is in the form of toxic bait.