What kills a spider mite? - briefly
Effective control agents include insecticidal soap, neem oil, and registered miticides, while predatory mites such as Phytoseiulus persimilis rapidly suppress infestations. Reducing excess nitrogen fertilization and maintaining low humidity further inhibit their reproduction.
What kills a spider mite? - in detail
Spider mites can be eradicated through several complementary strategies. Chemical agents include synthetic acaricides such as abamectin, bifenthrin, and spiromesifen; each disrupts nerve function or metabolic pathways, leading to rapid mortality. Resistance development is common, so rotating active ingredients with different modes of action is essential. Organic options comprise neem oil, which interferes with feeding and reproduction, and horticultural oils that suffocate all life stages when applied at full coverage. Both require thorough wetting of foliage and repeated applications at 5‑7‑day intervals.
Biological control relies on predatory arthropods. Phytoseiid mites (e.g., Neoseiulus californicus and Phytoseiulus persimilis) consume eggs and larvae, reducing populations by up to 90 % in greenhouse trials. Predatory insects such as lady beetle larvae (Stethorus punctillum) also target spider mites, especially on foliage with dense trichomes. Successful establishment demands minimal pesticide residues and adequate humidity.
Cultural measures diminish habitat suitability. Maintaining leaf surface humidity above 60 % hampers mite development; misting or drip irrigation can achieve this without promoting fungal disease. Removing heavily infested leaves and pruning overcrowded branches improve air circulation and limit reproduction. Regular inspection of the undersides of leaves enables early detection and prompt intervention.
Environmental manipulation includes temperature control. Raising ambient temperature to 30 °C for several days accelerates the life cycle, making mites more vulnerable to contact insecticides, while prolonged exposure to temperatures below 10 °C suppresses egg hatch rates. Implementing these thermal regimes in controlled environments can complement other tactics.
Integrated pest management (IPM) combines the above elements. A typical protocol starts with scouting, followed by the introduction of predatory mites, selective use of low‑toxicity oils, and, if thresholds are exceeded, targeted application of a synthetic acaricide with a different mode of action from previous treatments. Monitoring after each action confirms efficacy and guides subsequent decisions.