Spirodiclofen: A Modern Acaricide for Mite Control

Technical Introduction

Spirodiclofen (IUPAC name: 3-(2,4-dichlorophenyl)-2-oxo-1-oxaspiro[4.5]dec-3-en-4-yl 2,2-dimethylbutanoate) is a systemic acaricide belonging to the tetronic acid derivative group. It was introduced by Bayer CropScience and has become one of the most widely used acaricides in orchards and horticultural crops.

Its mode of action is unique:

• It inhibits acetyl-CoA carboxylase (ACCase), a key enzyme in lipid biosynthesis.

• This disruption leads to blocked fat metabolism in mites, impairing growth and reproduction.

• It acts primarily on immature stages (eggs, larvae, nymphs), but also reduces adult fertility.

Spirodiclofen is a slow-acting, long-residual acaricide, making it ideal for integrated pest management (IPM).

Applications

• Fruit Orchards:

  • Widely used on citrus, apples, pears, peaches, plums, and grapes.

  • Controls spider mites (Tetranychus spp., Panonychus spp.) and false spider mites (Brevipalpus spp.).

• Horticultural Crops:

  • Applied in greenhouses for vegetables and ornamental plants.

• Specialty Crops:

  • Used on tea, coffee, and ornamental flowers for mite infestations.

• Integrated Pest Management (IPM):

  • Selective against mites, but safer for beneficial insects (predatory mites, lady beetles), making it compatible with IPM strategies.

Advantages

• Selective Acaricide: Strong effect on mites, minimal impact on beneficial insects.

• Novel Mode of Action: Inhibits ACCase, reducing risk of cross-resistance with other acaricides.

• Effective on Multiple Stages: Suppresses eggs, larvae, and nymphs; reduces adult fecundity.

• Long Residual Activity: Provides extended protection (up to 6–8 weeks in orchards).

• Low Application Rate: Highly active even at small dosages, reducing chemical load.

• IPM-Friendly: Can be integrated with biological control and other selective pesticides.

Specifications (Typical Parameters)

FAQ

Q1: What makes Spirodiclofen different from older acaricides?
A: Unlike organophosphates or pyrethroids, Spirodiclofen has a new biochemical target (ACCase inhibition), providing a solution against resistant mite populations.

Q2: Does it kill adult mites directly?
A: It is more effective on eggs, larvae, and nymphs. While it does not kill adults immediately, it reduces their fertility, leading to long-term population suppression.

Q3: Can Spirodiclofen be mixed with insecticides or fungicides?
A: Yes, it is compatible with many agrochemicals, but tank-mix recommendations depend on local registration and crop guidelines.

Q4: Is it safe for pollinators and beneficial insects?
A: Yes, Spirodiclofen is considered IPM-friendly, with low toxicity to bees, predatory mites, and ladybird beetles.

Q5: What is the recommended spray timing?
A: It is best applied at the onset of mite infestation, before populations reach damaging levels, ensuring control of juvenile stages.