Tebufenozide

Tebufenozide is a highly selective insect growth regulator (IGR) belonging to the diacylhydrazine class. Its chemical formula is C22H28N2O2, with CAS number 112410-23-8.

Chemical class: It belongs to the chemical class of diacylhydrazines (IRAC Group 18: ecdysone receptor agonists).

Mechanism of action: It acts as a non-steroidal agonist of the ecdysone receptor (EcR). It mimics the natural molting hormone of insects, 20-hydroxyecdysone (20E). It binds strongly to the EcR/USP receptor complex, activating molting genes prematurely and in a dysregulated manner. This causes: immediate cessation of feeding, formation of a malformed cuticle, death of larvae due to starvation and dehydration.

The action is primarily stomachic (with some contact), not systemic, with good residual activity on the leaves. It is highly selective for lepidoptera (caterpillars), with low impact on mammals, birds, fish, and most natural enemies (predators and parasitoids).

Control spectrum: It primarily controls Lepidoptera larvae (butterfly and moth caterpillars), especially in early stages (1st to 3rd instar).

Main names of commercial products: Mimic 240 SC

Development history: Developed by Rohm and Haas Company (now Corteva). Discovered around 1986; part of the diacylhydrazine class since 1983. It was one of the first "reduced-risk" insecticides registered by the US EPA, with a high degree of selectivity.

Agronomic positioning: Apply preferably to young larvae (better efficacy). Stomach action requires good plant coverage. Good foliar residual action. Recommended in rotation with other chemical groups (avoid repeated use of Group 18) for resistance management.

Compatibilities and interactions: Compatible with IPM programs due to selectivity. Check labels for tank mixtures (generally compatible with many selective fungicides and insecticides). Avoid mixtures that may compromise the subcutaneous formulation or reduce efficacy. Low risk to bees and parasitoids when used as recommended.

Other information:

After 74 generations of laboratory selection with tebufenozide in Spodoptera exigua, resistance of approximately 92 times was obtained. The resistance is autosomal, incompletely recessive, polygenic, with a fitness cost and involvement of oxidative metabolism. DOI: 10.1002/ps.1785 

First reports of field resistance to tebufenozide in Cydia pomonella (cowpea moth) in France (Avignon region). Mechanisms include metabolic detoxification. Monitoring and early detection were studied in subsequent work. - DOI: 10.1111/j.1439-0418.2007.01203.x -

Selection for resistance to tebufenozide in Plutella xylostella (diacylhydrazines) and evaluation of cross-resistance with other IGRs (benzoylureas and diacylhydrazines). DOI: 10.1002/ps.1234

Tebufenozide resistance in Adoxophyes honmai (lesser tea moth) in Japan, with studies on mechanisms and early detection. - DOI: 10.1007/s13355-019-00616-2 -