This document discusses bio-pesticides, which are pesticides derived from natural materials like microorganisms or plant extracts. It defines three main types - microbial pesticides containing bacteria, fungi or viruses; biochemical pesticides containing plant extracts; and plant-incorporated protectants where pesticidal genes are inserted into plants. The document uses the example of Bacillus thuringiensis (Bt) to explain the mode of action of microbial bio-pesticides. It also outlines the large-scale production process and some commercially available options, advantages and potential issues with bio-pesticides.