What causes spider mites to appear in orchids? - briefly
Warm, dry environments with high temperatures and low humidity create ideal conditions for spider mite proliferation on orchids, especially when plants are overcrowded or lack proper air circulation. Introduction of infested plant material or insufficient sanitation can also trigger outbreaks.
What causes spider mites to appear in orchids? - in detail
Spider mites infest orchids when conditions favor rapid population growth and when the plants experience stress. Key contributors include:
- Low humidity: Air moisture below 40 % accelerates mite reproduction and increases their survival rate.
- High temperatures: Sustained temperatures above 25 °C shorten the mite life cycle, allowing multiple generations per month.
- Poor air circulation: Stagnant air creates micro‑environments where humidity drops and heat accumulates, both of which benefit the pest.
- Nutrient deficiencies: Lack of essential nutrients, especially potassium and calcium, weakens plant defenses, making tissue more attractive to feeders.
- Watering irregularities: Over‑watering leads to root rot and stress; under‑watering causes leaf desiccation—both conditions trigger mite colonization.
- Contaminated tools or substrates: Introduction of mites through infested pots, soil mixes, or pruning equipment spreads the infestation across collections.
- Adjacent host plants: Presence of other susceptible species (e.g., citrus, beans, roses) provides a reservoir for mites to migrate onto orchids.
- Chemical stress: Overuse of pesticides or fungicides can suppress natural predators, allowing mite numbers to surge unchecked.
Each factor can act alone or in combination, creating an environment where spider mites thrive and quickly overwhelm orchid foliage. Managing humidity, temperature, airflow, nutrition, and sanitation simultaneously reduces the likelihood of an outbreak.