Explain the mode of action of organophosphate and Bacillus thuringiensis which are used in pest management?.

Organophosphates and Bacillus thuringiensis (Bt) are two distinct pest management agents with different modes of action:

Organophosphates:

• Inhibit acetylcholinesterase (AChE) enzyme

• Prevent breakdown of acetylcholine neurotransmitter

• Lead to overstimulation of nerve synapses

• Cause paralysis and death in insects

• Affect both target pests and non-target organisms

Key effects: Neurotoxicity, enzyme inhibition

Bacillus thuringiensis (Bt):

• Produces crystal (Cry) proteins

• Cry proteins dissolve in insect gut, becoming active toxins

• Toxins bind to receptors in gut epithelial cells

• Create pores in cell membranes, causing cell lysis

• Leads to septicemia and insect death

Key features: Species-specific, gut-active

Both methods are effective in pest management, but Bt is generally considered more environmentally friendly due to its specificity. Organophosphates have broader toxicity, potentially affecting beneficial insects and other organisms. Bt's targeted approach reduces ecological impact while still providing effective pest control in agriculture and public health applications.