READINGS: (the below articles are not in a proper essay structure)
Bacillus thuringiensis (Bt) was first isolated in 1901 by a Japanese biologist Ishiwata
Shigetane as he studied the causes of a disease infecting silkworms. In 1911, Ernst Berliner re-
isolated the bacterium from a flour moth caterpillar from Thuringia, Germany, hence the species
name. Berliner discovered that Bt produce toxin that can be used against certain insect larvae,
and not others. Despite its early discovery, Bt was not harnessed its pesticide potential not until
1928.
Bt Corn is a genetically modified corn infused with a gene that came from the said
bacterium. The transgenic corn inherits the trait of the bacterium of producing an inactive protein
called the Bt toxin. When insects ingested the toxin, it will be converted to its active and toxic
form, Bt delta endotoxin which are highly toxic for the gut of the insect. The toxin will destroy
the gut of the insect, punching holes to its walls that will be the pathway of the toxin’s spores
into the insect’s internal body structure, poisoning it, that will eventually lead to its demise
through septicaemia (poisoning of blood due to bacteria, causing sepsis to ensue). This toxin
only kills certain taxonomic order of insect larvae, including corn borers which destroys corn
crops that cause decrease in overall yield. There have been no surprising effects on non-target
organisms observed with Bt maize, which confirms the specificity of the Bt proteins. Most
studies suggest Bt maize has little if any impact on predators and parasitoids and, when
compared with maize treated with chemical insecticides, Bt maize often results in increased
biodiversity [for general reviews see (O'Callaghan et al. 2005, Romeis et al. 2008)]. Specialist
insects that depend on target pests are the exception to the generalization that Bt maize does not
impact non-target organisms.
According to International Service for the Acquisition of Agri-Biotech Applications
(ISAAA) director, Dr. Rhodora Aldemita, Filipino farmers recorded a 30-50% decrease of corn
borers to their fields since planting Bt corns, which lead to a higher yield. This also caused
decline in pesticide use. According to United States Department of Agriculture (USDA),
between 1995 to 2010, the use of pesticides in the fields of Bt corns were reduced by 99%, and
estimated 35% globally in the years 1996 to 2008 (Brookes and Barfoot, 2010). The transgenic
form of this crop made promising results, and its use proliferated and still adopted up until this
moment. According to Statista, total acreage of GMO crops in 2018 peaked at 191.7 million
hectares globally. Global demand in Bt corn also increased by 45% from year 1997 to 2020
(International Service for the Acquisition of Agri-Biotech Applications (ISAAA), 2020)
Bt Corn was first introduced in the Philippines in 1996 on a limited trial basis only.
Between1999 and 2002, after approval from the National Committee on Biosafety in the
Philippines, field trials were conducted in the major corn-producing areas in the country. Finally,
in 2002, the Philippine Department of Agriculture approved the commercial distribution of Bt
corn, that made the Philippines the first country in Asia to commercialize it. Primarily in
response to the Asian corn borer pests, it is expected to possibly improve corn productivity in the
country since corn yields have remained low and corn imports have increased over time.
