Little Black Mites on a Rabbit's Foot Fern

Mites

• Tiny, sometimes even microscopic pests, mites are not insects but are closely related to spiders and ticks. These creatures devastate ferns by sucking the juice from the undersides of the foliage, leaving pale leaves surrounded by webbing that they use to travel from leaf to leaf. If left untreated, the fern is not likely to survive. It is difficult to detect an infestation early, but on close inspection, you may see what looks like yellow pin-pricks on the undersides of leaves.

Mites Versus Thrips

• The damage caused by mites and thrips looks similar, and both insects look like tiny black spots on a plant -- if you can see them at all. To distinguish between the two, place a white sheet of paper under the foliage, and tap the rabbit’s foot fronds until a few of the pests land on the paper. Mites are moving dots, while thrips are relatively inactive slivers. If you see webbing between and under the fronds, the cause is likely spider mites.

Remedies

• A shower is a mite’s worst enemy. Place your fern in a lukewarm shower for several minutes to dislodge mites and create an inhospitable environment for their return. Repeat the process every two weeks until you no longer see signs of mites. Between showers, spray the fern several times with warm water. Dusty leaves encourage mites, so clean your rabbit’s foot fern regularly. Use a spray of water or a clean soft cloth, but never use a feather duster, which can spread mites.

Insecticides

• Rabbit’s foot ferns are very sensitive to insecticides, including those generally considered safe for indoor plants such as insecticidal soap. If you can’t control mites without an insecticide, choose a product that is labeled as being safe for ferns, and test the insecticide on a small part of the plant before spraying it on the entire plant. Carefully read and follow the instructions when applying insecticides, and when the weather permits, take the fern outside for treatment.