HOT-WATER TREATMENT AND COLD STORAGE TO CONTROL THE BULB MITE RHIZOGLYPHUS ROBINI ON LILY BULBS.

Lily bulbs can be heavily infested and destroyed by the bulb mite Rhizoglyphus robini either during the process of propagation by scaling, in storage or during the growing season in the field.
Therefore, control measures are necessary, such as a bulb treatment with pirimiphos-methyl, which is used by Dutch growers nowadays.

To reduce the dependence on chemicals, other potential control measures were investigated.
Experiments with hot-water and cold-storage treatments of mite-infested lily bulbs showed that 98 – 99% of the mites were killed when the bulbs were dipped in water for 2 hours at 39°C or 41°C, and that more than 99% were killed after a storage period of 6 months at -2°C.

Infested bulbs were either hot-water treated or not and scales from these bulbs were put in plastic bags with moist vermiculite (temperature 23°C and high relative humidity) to induce adventitious bulblet formation.
Surprisingly, scales and bulblets from hot-water-treated bulbs became more severely infested by the mites than those from untreated bulbs.
The predatory mite Hypoaspis aculeifer, which was present on the bulbs and killed by the hot-water treatment, may have been responsible for this phenomenon.

VI International Symposium on Flower Bulbs

C.G.M. Conijn

Hypoaspis aculeifer, scaling

https://doi.org/10.17660/ActaHortic.1992.325.117