What it is & how it works
Q1: What is Naturalis®-L and what does it do?
Naturalis®-L is a biological insecticide based on the naturally occurring entomopathogenic fungus Beauveria bassiana, providing effective control of all life stages of whitefly and a useful reduction in thrips in edible and ornamental crops under permanent protection.
Q2: How does Beauveria bassiana kill insects?
Beauveria bassiana works by contact - fungal spores land on the insects's cuticle, germinate, and physically penetrate the insect's body, proliferating inside to cause desiccation and death, with no need for ingestion.
Q3: Which pests does Naturalis®-L target?
Naturalis®-L is approved for the control of all whitefly species (including glasshouse whitefly Trialeurodes vaporariorum) and for a reduction in thrips (including Western Flower Thrips Frankliniella occidentalis) in crops under permanent protection.
2. Application & use
Q4: Which crops is Naturalis®-L approved for use on?
Naturalis®-L is approved for use on all edible crops (protected) and ornamental plant protection (protected), plus protected forest nursery under EAMU 2195/2016 - but it is approved only for crops under permanent protection and cannot be used outdoors.
Q5: When should I apply Naturalis®-L, and what conditions does it need to work?
Apply at the very first signs of whitefly or thrips, in the morning or evening when humidity is higher and adult insects are less active - Naturalis®-L works best between 20°C and 30°C with relative humidity above 60%.
Q6: How do I mix and apply Naturalis®-L correctly?
Apply at 0.3% v/v (3 litres in 1,000 litres of water) using a fine spray to achieve complete plant coverage to just before run-off - equipment must be clean and free of all pesticide residues before use, with continuous agitation throughout.
3. Tank mixing & fungicide compatibility
Q7: Can Naturalis®-L be tank mixed with other products?
No - Naturalis®-L must not be tank mixed with any other product; this is a label requirement, not simply a precaution, as mixing with other chemicals risks damaging spore viability before application.
Q8: Can I apply a fungicide in the same spray programme as Naturalis®-L ?
A minimum of 48 hours must be left after a Naturalis®-L treatment before applying any fungicide - some fungicides reduce the effectiveness of Naturalis®-L, and the effects of fungicides applied before a treatment have not been fully evaluated.
4. IPM & Holistic Growing
Q9: How does Naturalis®-L fit into an IPM programme?
Naturalis®-L is well-suited to IPM programmes - its unique Group UNF mode of action provides a valuable rotation option, no insect resistance has been reported, and it is compatible with many beneficial insects, though growers should monitor carefully around Encarsia sp.
Q10: Is there a risk of resistance developing to Naturalis®-L?
No insect resistance to Beauveria bassiana has been reported - its physical mode of action (cuticle penetration) makes resistance far less likely to develop than with conventional chemistry, though IPM rotation remains best practice.
5. Safety, storage & handling
Q11: What PPE is required when handling and applying Naturalis®-L?
Operators must wear coveralls, suitable protective gloves, and an FFP3 disposable filtering facepiece respirator when handling the concentrate or applying the product - COSHH regulations may apply to professional use.
Q12: How should Naturalis®-L be stored?
Naturalis®-L has a guaranteed shelf life of one year at room temperature, but should ideally be stored at 4–5°C to maximise spore viability - do not freeze.
6. Commercial & practical
Q13: Why is Naturalis®-L only available through Fargro, and what support do we orrder?
Fargro is the exclusive supplier of Naturalis®-L in Great Britain - which means our technical team has direct access to the manufacturer’s expertise and can provide spray programme, IPM, and biological compatibility advice that no other supplier can match.
