How long can spider mites survive without plants?
Written by
Liu Xiaohui
Reviewed by
Prof. Martin Thorne, Ph.D.Spider mites typically die quickly without host plants, usually perishing within two to five days. They cannot feed on anything but plant material; however, they may enter a state of hibernation during cold weather. I found them starving on empty shelves in a greenhouse after removing ferns that they had infested. They cannot live long unless they can find new host plants speedily.
Lifespan Factors
- Adults survive 2-5 days without plant sap nutrition
- Dormant eggs persist 2-3 weeks in crevices or soil
- Cool temperatures below 60°F (15°C) extend dormancy periods
- High humidity above 70% accelerates egg hatching
Sanitation Measures
- Scrub surfaces with 10% bleach solution to kill eggs
- Steam-clean soil at 140°F (60°C) for 30 minutes minimum
- Seal gaps in greenhouse structures with silicone caulk
- Dispose plant debris in sealed bags never compost
Eggs have the greatest potential for reinfestation, as they can survive from one to three weeks under suitable conditions. They lodge in crevices of the soil, under pots, and in the joints of the greenhouse. Having lost plants from recurring invasions, I now steam-sterilize all soil when it is not in use. A temperature of 140°F (60°C) and above is likely to destroy the eggs.
Conduct thorough cleanups immediately after removing the diseased plants. Scrub surfaces with bleach solution, paying special attention to crevices. Seal cracks with silicone in the greenhouse where eggs might find refuge. I use stiff brushes for the textured surfaces to ensure that all residue is removed. It is essential to allow treated areas to dry thoroughly before replanting.
Vigilantly watch the empty spots when the plants are in the waiting period. Use strips of yellow stickum where empty pots are placed, which will catch loose mites looking for a host. Force the temperature above 75 °F (24 °C) to hasten the starving process. My greenhouse is kept empty for 25 days after a bad infestation so that all stages of life can be eradicated before resetting.
Prevent survival of dormancy with environmentals. High temperatures and low humidity create an inhospitable situation. I keep dehumidifiers and heaters running in empty grow rooms to maintain optimal conditions. This protocol has cured my chronic reinfestation problems, which have destroyed three consecutive crops of plants before.
Read the full article: Ultimate Spider Mite Control Guide
