Bulb mite

Taxonomic classification: Rhizoglyphus robini is a member of the Acaridae family within the order Acariformes. It is a tiny, translucent arachnid that thrives in soil environments, often going unnoticed until significant damage is already caused to the plant's root system.

Host plants: The bulb mite has a broad host range, primarily affecting bulbous and tuberous ornamentals such as lilies, tulips, hyacinths, and gladioli. It also causes significant economic losses in vegetable crops, including garlic, onions, carrots, and potatoes during storage.

Biology and life cycle: The pest's life cycle is highly sensitive to humidity and temperature. Optimal conditions involve moisture levels above 60% and temperatures around 20–25°C. The mite progresses through several stages: egg, larva, protonymph, deutonymph, and adult. The deutonymph stage, often called a hypopus, is a highly resistant, non-feeding phase that enables the mite to survive extreme conditions or hitchhike on insects to reach new areas.

Nature of damage: Bulb mites feed by boring into the basal plate of the bulb. This wounding allows secondary pathogens, such as fungi and bacteria, to enter the tissue, causing rapid decay. Symptoms include stunted plant growth, chlorosis, root necrosis, and in severe infestations, the complete collapse of the bulb tissues.

Control measures: Management depends on strict sanitation. Growers should remove and destroy infested bulbs, ensure proper soil drainage, and maintain optimal storage conditions with low humidity and cool temperatures. Chemical control involves soaking bulbs in acaricidal solutions before planting to eradicate dormant stages of the pest.