Uses of Bt insect resistance in agriculture
This remarkable finding which happened in 1911 was not the first time Bt went under close inspection; in the Far East, ten years before, a Japanese scientist who was investigating the almost instantaneous death of silkworms first discovered it.
More than a century has now passed since Bt's discovery, and for more than half of it, Bt has been used as a natural insecticide, being sprayed onto crops. (Shelton 2008) But just how does Bt work in the first place'
Unlike Dichlorodiphenyltricloroethane, which has been known to be a three-letter acronym for the words notorious killer because of its infamousness in inflicting damage to organisms it should not, Bt is not a contact poison. Bt has to be eaten first before it can poison any unsuspecting insect. B. thuringiensis has spores which contain crystal proteins or cry proteins. When ingested by an insect, the active insecticidal crystal protein or (ICP) breaks down in the insect's gut and releases a toxin called delta-endotoxin. This delta-endotoxin then reacts with certain receptors on the intestinal lining and makes pores causing the leakage of its contents and paralyzation of the insect's digestive system resulting to insect death. The killing is a slow process that may take hours or even days. (Shelton 2008) However, it must be noted that because of the paralysis of the insect’s digestive system, the insect soon stops eating. Immediately dead or not, the goal of saving the crops from mass mastication of unwanted living forms is definitely achieved. ...