Tolfenpyrad (Nichino Tychi)

Tolfenpyrad is a pyrazole insecticide-miticide developed by Nichino (Mitsui Chemicals Agro) and marketed in India as Tychi 15% EC. It is a broad-spectrum, fast-knockdown contact insecticide with secondary fungicidal activity on powdery mildew and anthracnose.

Composition / Active ingredient

Active ingredient: Tolfenpyrad
Formulation: 15% EC (emulsifiable concentrate)
Chemical class: Pyrazole-5-carboxamide (METI — mitochondrial electron transport inhibitor)

Mode of action

Tolfenpyrad inhibits mitochondrial Complex I (NADH:ubiquinone reductase) of the electron-transport chain. Without functional Complex I the insect cannot produce ATP; activity is rapid (24-48 hours to knockdown). It is classified under IRAC Group 21A. Action is by contact and ingestion, with strong antifeedant effect and ovicidal activity against diamondback moth eggs. The molecule is non-systemic — translocation in plant tissue is minimal — so thorough spray coverage of both leaf surfaces is essential.

Target use and dose

CIBRC-registered uses include paddy, chilli, cotton and vegetables. Target pests:

Sucking pests: aphids, whitefly, jassids, thrips
Chewing pests: diamondback moth, leaf miner
Mites: secondary activity on spider mites

Standard rate is 200-400 ml/acre depending on crop and pest pressure. The compound is positioned as a rotation partner for IRAC Group 6 (Emamectin Benzoate), Group 23 (Spiromesifen Oberon, Spirotetramat Movento) and Group 12A (Diafenthiuron Pegasus).

Safety and regulatory status

Tolfenpyrad has higher acute mammalian toxicity than some newer chemistries; full protective equipment is required. It is harmful to fish and bees; spray during evening hours and avoid flowering. As a Group 21A METI, it shares a binding-site class with fenpyroximate and pyridaben; rotation among these three should be avoided within a generation to prevent cross-resistance build-up.

References

Tychi — Tolfenpyrad 15% EC. Nichino India.
Tolfenpyrad active ingredient profile. IRAC.