Fipronil, Spiromesifen, Spinosad + Tolfenpyrad and Matrine: Insecticide Buyer Guide

Fipronil, spiromesifen, spinosad, tolfenpyrad and matrine each come from a different insecticide group, which makes them useful rotation partners for the more common pyrethroids, neonicotinoids and organophosphates. They also differ sharply in target pests, speed of action and bee safety. Buyers get the best value from them by matching each to the pests on its label and to the gaps in an existing rotation.

Averstar's catalogue lists fipronil 15% SC, spiromesifen 240 g/L SC, a spinosad and tolfenpyrad 5% / 20% SC and matrine 0.3% SL. This guide explains what each does and which documents to request. The approved destination-market label always decides the crops, pests, situations, dose and restrictions for the product actually supplied.

Quick answer: Use spiromesifen against whiteflies and mites, the spinosad and tolfenpyrad mixture against thrips, caterpillars and sucking pests on its label, fipronil only for the soil, crop or non-crop uses registered in the market, and matrine where a botanical product is wanted. Each sits in a different IRAC group, so they can fill gaps in a rotation.

Fipronil

The University of Hertfordshire Pesticide Properties Database (PPDB) describes fipronil as a broad-spectrum insecticide with contact and stomach action against ants, beetles, cockroaches, termites, thrips, fleas and other pests, with example uses in maize, potatoes, turf and ornamentals. It blocks GABA-gated chloride channels, which the IRAC mode of action classification places in Group 2B. Crop, public-health and veterinary uses are registered separately. Our emamectin benzoate guide covers the emamectin and fipronil mixture.

Spiromesifen for whiteflies and mites

The PPDB describes spiromesifen as a selective, non-systemic tetronic acid insecticide used against whiteflies and mites, including two-spotted spider mite and broad mite, on vegetables such as cucumbers, peppers, tomatoes and melons, on strawberries and on ornamentals. It inhibits acetyl-CoA carboxylase and lipid formation, IRAC Group 23. Products in this group act most strongly on eggs and immature stages, so they work best when applied early in an infestation. Our acaricide guide covers other mite products.

Spinosad and tolfenpyrad

• Spinosad: the University of Hertfordshire Bio-Pesticides Database (BPDB) describes secondary metabolites of the soil bacterium Saccharopolyspora spinosa with contact and stomach action against thrips, caterpillars, leaf beetles, Colorado potato beetle and leafminers, used in onions, corn, leafy vegetables, potatoes, tomatoes, peppers and fruit. IRAC places spinosyns in Group 5.
• Tolfenpyrad: a broad-spectrum contact insecticide, mainly for high-value crops such as vegetables, tea and fruit, against aphids, leafhoppers, scale insects, thrips, whiteflies and psyllids, with antifeedant activity against caterpillars. It inhibits mitochondrial complex I, IRAC Group 21A, and the PPDB also notes some activity against powdery mildew.

The spinosad + tolfenpyrad 5% / 20% SC therefore combines two modes of action; confirm that the mixture is registered for the intended crop and pests in the destination market.

Matrine, a botanical option

The BPDB describes matrine as a natural plant alkaloid, obtained from plants such as the roots of Sophora flavescens, active against aphids, spider mites, diamondback moth, caterpillars and other pests, with example uses in glasshouse crops and crucifers. Botanical products contain low concentrations of active ingredient, so their specifications, labels and performance expectations differ from synthetic insecticides. The catalogue also lists an imidacloprid and matrine WP.

Rotation, bees and registration

Because these actives sit in different IRAC groups (2B, 23, 5 and 21A), they can replace one another in a rotation; repeated use of the same group should still follow the label limits. Bee safety differs widely: the PPDB lists a honeybee contact LD50 of 0.0059 micrograms per bee for fipronil, which is extremely toxic, and labels set strict pollinator restrictions. The PPDB records fipronil, spiromesifen and tolfenpyrad as not approved in the European Union, so confirm the current status and residue limits in each destination and importing market.

Compare the catalogue formulations

• Suspension concentrates: Fipronil 15% SC, Spiromesifen 240 g/L SC and the spinosad + tolfenpyrad SC, which need agitation before use and are tested for suspensibility.
• Matrine 0.3% SL: a soluble concentrate at a low concentration, typical of botanical products.

Penn State Extension's overview of pesticide formulations compares these types, and FAO/WHO pesticide specifications describe the properties buyers test.

A product selection checklist

• Target pests by species and stage, matched to the pests named on the label.
• The IRAC groups already used, so the new product fills a gap in the rotation.
• The registered use: field crop, glasshouse, public health or veterinary.
• Pollinator restrictions, especially for fipronil.
• Current registration status and residue limits in the destination and importing markets.
• Concentration and unit matched on quotation, certificate of analysis and label.
• Packaging, safety data sheet and translated label artwork.

Build the inquiry around the intended use

Send the crop or situation, the target pests, the insecticides already used, the preferred product and concentration, the packaging and the destination market through our contact form. For a first order, a pesticide sample evaluation plan helps compare samples against the agreed specification before scaling up.