Non-Repellent vs Repellent Chemistry
Understanding the difference between insecticides pests cannot detect (non-repellent) versus those they avoid (repellent) - critical for colony elimination.
Detailed Overview
Repellent insecticides (pyrethroids like permethrin, cypermethrin, bifenthrin) are detected by insects causing avoidance behavior before lethal contact. Pests sense chemical and walk around treated areas - may even abandon established trails and harborage if repellent applied. Creates "halo effect" pushing pests to untreated areas. Non-repellent insecticides (fipronil, indoxacarb, chlorfenapyr, imidacloprid) cannot be detected - pests walk through treatments unknowingly, contact active ingredient, and continue normal behavior before dying. Critical advantage: transfer effect - treated insects return to harborage, groom, share food, die among colony members who also become contaminated, creating cascade effect eliminating entire colony. For ants and termites (social insects with trophallaxis), non-repellents vastly superior. For perimeter barriers, non-repellents prevent pests from simply going around treatment. When to use repellents: outdoor perimeter treatments for immediate barrier (keeps bugs away), situations requiring visible immediate knockdown. When to use non-repellents: ant and termite colony elimination, indoor German roach treatments, situations where transfer effect desired. Modern PCO practice favors non-repellents for most applications despite higher cost.
When to Use
Use non-repellents for ant colony elimination, termite treatments, German roach control, and situations where transfer effect needed. Use repellents for outdoor barriers where repellency prevents entry.
Required Skill Level
Should only be performed by licensed pest management professionals
Benefits
- Non-repellents: transfer effect eliminates entire colonies
- Pests cannot detect and avoid non-repellent treatments
- Superior for social insects (ants, termites)
- Prevents pest displacement to untreated areas
- More complete control than repellent products
Limitations
- Non-repellents typically more expensive
- Slower knockdown than repellent pyrethroids
- Some non-repellents highly toxic to fish
- Requires understanding of when each type appropriate
Related Concepts
Other product types that may be useful
Reduced-Risk Pesticides
Low-toxicity pesticide products that pose minimal risk to humans, pets, and the environment while remaining effective against target pests.
Insect Growth Regulators (IGRs)
Pesticides that disrupt insect development and reproduction by mimicking or blocking growth hormones - providing long-term population suppression.
Desiccant Dusts
Insecticidal dusts that kill by physically abrading the waxy cuticle causing dehydration - cannot be resisted and provide permanent control if kept dry.