Biflex TC and Agenda 25 EC are among the best-known termite insecticides, and both are used to create a soil barrier that protects a building. But they work differently: Biflex repels and kills at the barrier, while Agenda does not repel, so termites pass through it and carry the effect into the colony.
This article explains the difference between them, when to choose each one, and how to use them before and after construction.
The quick difference
- Biflex TC (FMC): contains bifenthrin and forms a repellent barrier that kills on contact. It stops termites at the barrier and is best used before construction and around foundations.
- Agenda 25 EC (Envu): contains fipronil 2.5% and forms a non-repellent barrier. Termites pass through it and carry the effect back to the colony, so it suits existing infestations after construction.
How does Biflex TC work?
Biflex contains bifenthrin, a pyrethroid. When sprayed into the soil it forms a chemical barrier that kills termites on contact and repels those that approach. Its strengths:
- Long-lasting in soil, protecting foundations for years.
- Does not wash away easily, so it stays in place around the building.
- Suits soil treatment before pouring foundations and under tiles.
More on the active in Bifenthrin: The Termite Insecticide and the Chemical Barrier Around the House.
How does Agenda 25 EC work?
Agenda contains fipronil 2.5%, a non-repellent insecticide. Termites do not detect the barrier, so they pass through it, pick up the active, return to the colony and pass the effect to others by contact and feeding. That is why:
- It works on existing infestations, reaching termites that never touched the product directly.
- The kill is gradual, so the colony declines over several weeks.
- It is used before and after construction, at a higher concentration before construction.
On fipronil, read Fipronil: How a Dot of Gel Clears a Cockroach Nest.
When should you choose each one?
- New ground before building: Biflex TC is an excellent choice for a long-term barrier under the foundations.
- An existing building with a clear infestation (mud tubes, eaten wood): Agenda 25 EC is better because it reaches the colony.
- You want strong long-term protection: some programmes use one for the main barrier and the other for treating infestation points.
Mixing rates
- Agenda 25 EC before construction: 25 ml per litre of water.
- Agenda 25 EC after construction: 15 ml per litre of water.
- Biflex TC before and after construction: 1 litre per 400 litres of water, which is 2.5 ml per litre.
Use before construction
- Level the soil and remove wood debris and roots from the site.
- Prepare the solution at the mixing rate above.
- Spray the soil at 5 litres of solution per square metre across the foundation area and the paths around the building.
- Cover the treated soil with polythene or concrete quickly so it is not disturbed.
Example: a 100 m² slab needs 500 litres of solution. With Agenda that is 12.5 litres of product, and with Biflex 1.25 litres of product.
Use after construction
- Locate the infestation and the mud tubes. How termites look is covered in What Termites Look Like: How to Tell Them from Ants and Spot Them in Wood.
- Drill holes in the floor along the walls and foundations, 40 to 50 cm apart and 30 to 35 cm deep.
- Inject 2 litres of solution into each hole, then seal the holes with cement.
- Treat joints and cracks in floors where termites enter.
- Fix water leaks and damp, because termites love moist places.
For large infestations or ones inside walls, visit your nearest Orkida branch and we will prepare the right quantity and injection equipment for you.
Safety
- Wear gloves, goggles and a mask while preparing and spraying.
- Do not spray near water wells or drinking water sources.
- Keep children and pets away until it dries.
Products from Orkida
- Agenda 25 EC, 1 litre: fipronil 2.5% from Envu, a non-repellent barrier with a transfer kill for termites.
- Agenda 25 EC, 100 ml: the same product in a small pack for spot treatments.
- Biflex TC, 1 litre: bifenthrin from FMC for a long-term soil barrier before and after construction.
Frequently Asked Questions
Which is stronger, Biflex or Agenda?
Both are strong; the difference is in how they are used. Biflex is better for a pre-construction barrier, and Agenda is better for existing infestations because it reaches the colony.
Can I mix them together?
Do not mix them in the same tank. If you want to use both, apply each in its own place according to the programme.
How long does the barrier last?
According to the product data, a correctly applied Agenda barrier protects for at least 5 years. The actual period varies with soil type and moisture, so inspect the building every year.
Do they work on ordinary ants?
They are made for termites. For ordinary ants inside the home, gels and baits are more suitable and safer.