RNA Bioinsecticides Are Moving Into Field Trials: What Farmers Should Watch

Promise: Protected RNA products are being tested across continents, but delivery stability, pest timing and cost will decide whether they become practical farm tools.

Farmers managing fall armyworm, diamondback moth and other caterpillars need new modes of action. Resistance can reduce the value of older insecticides, while broad-spectrum sprays may disrupt beneficial insects. RNA-based bioinsecticides aim to silence genes that the target pest needs to survive.

AgroSpheres and FMC recently announced that two RNA biomolecule candidates are moving into global field development across the United States, Brazil and Asia. The companies say the candidates advanced through laboratory, greenhouse and small-plot testing and were benchmarked against industry-standard chemistries.

The precise targets and full data are not public. Still, the development step matters because field exposure is where RNA products face their hardest test: sunlight, heat, rain, leaf-surface enzymes and uneven pest feeding.

How RNA insect control works

Double-stranded RNA can trigger a natural process called RNA interference. When the target insect takes up the correct RNA sequence, the process reduces expression of an essential gene. Because sequences can be designed for a specific pest, the approach may reduce effects on organisms that do not share the target sequence.

Precision does not automatically guarantee zero non-target risk. Product developers still need sequence screening, laboratory testing and ecological risk assessment. Farmers also need clear guidance on pest stage and application timing because the insect must receive an effective dose.

Why formulation may be the real breakthrough

Naked RNA breaks down quickly outdoors. AgroSpheres describes its AgriCell platform as an encapsulation system that protects biomolecules from UV light, heat and moisture and provides controlled release. If that performance holds across climates, it could solve one of the central barriers to sprayable RNA.

For tropical and subtropical production, storage stability is equally important. A product that performs after refrigerated laboratory storage may fail after weeks in a hot warehouse or transport vehicle. Accelerated storage and package integrity data should be part of commercial evaluation.

Six things farmers should watch

1. Named pest and life stage. A product for one caterpillar should not be assumed to control another. Early larval stages may be easier to control than large larvae.
2. Rainfastness and sunlight persistence. Ask how quickly efficacy falls after rainfall and intense sunlight.
3. Speed of control. Gene silencing may not produce immediate knockdown. Measure feeding damage as well as insect mortality.
4. Resistance plan. Precision products still need rotation, mixtures where approved and monitoring for reduced sensitivity.
5. Effects on beneficial organisms. Demand data for pollinators, predators and parasitoids relevant to the crop.
6. Cost per protected hectare. Manufacturing and formulation costs must fit the crop’s value and pest pressure.

What an on-farm trial should include

Compare the RNA product with an untreated check, the farm standard and an integrated program. Apply at a recorded pest density and larval stage. Count larvae and fresh feeding injury before treatment and at several intervals afterward. Record rainfall, temperature, spray volume and adjuvant.

For smallholders, application simplicity matters. A product requiring cold storage, precise water chemistry or repeated high-cost applications may struggle even if biological efficacy is strong.

Cautions

The current announcement is a company pipeline update, not a registration or a complete public efficacy dataset. Global field trials can still reveal inconsistent performance, manufacturing constraints or unacceptable economics. Farmers should follow the evidence and local registration status rather than treating “RNA” as a guarantee.

Conclusion

RNA bioinsecticides could add valuable precision to caterpillar management. Their commercial future will depend on protected delivery, correct timing, resistance stewardship and affordable performance under real weather. Those are the milestones worth watching.

Source: AgroSpheres and FMC global field-trial announcement, September 17, 2026.

Discussion: Which pest would make a precise RNA insecticide most valuable on your farm?