Why does Fitoverm not work against spider mites? - briefly
Fitoverm’s active ingredients are designed to affect insects that possess specific nervous‑system receptors, which spider mites do not have. Therefore the product delivers no lethal effect on the mite population.
Why does Fitoverm not work against spider mites? - in detail
Fitoverm contains the active ingredient spirotetramat, a systemic insecticide that interferes with lipid synthesis in insects. Spider mites belong to the class Arachnida, not Insecta, and their physiology differs substantially from that of true insects. Their cuticle is more resistant to systemic uptake, and the mode of action of spirotetramat does not affect the biochemical pathways that regulate mite development and reproduction.
Key reasons for the lack of control:
- Target specificity – spirotetramat blocks acetyl‑CoA carboxylase, an enzyme essential for insect lipid metabolism. Arachnids rely on alternative metabolic routes, rendering the inhibition ineffective.
- Feeding behavior – the compound is absorbed by the plant’s phloem and distributed to feeding insects. Spider mites feed on the plant’s epidermal cells, accessing only surface tissues where systemic concentrations are negligible.
- Penetration barriers – the mite’s exoskeleton and waxy coating limit trans‑cuticular absorption of the product, preventing sufficient dose accumulation.
- Resistance mechanisms – some mite populations possess detoxification enzymes (e.g., cytochrome P450 monooxygenases) that can metabolize spirotetramat derivatives, further reducing efficacy.
Because of these biological and chemical mismatches, applying Fitoverm does not produce the mortality or reproductive suppression observed in susceptible insect pests. Effective management of spider mites requires acaricides that target mite‑specific pathways, such as calcium channel blockers, mitochondrial inhibitors, or products containing abamectin, hexythiazox, or bifenthrin, combined with cultural practices that reduce humidity and limit host plant suitability.