Fungus gnats are three to six millimetre black flies. The adults are harmless but the young maggots live in the soil and feed on the roots and crown. They thrive in moist soil. Affected plants will be stunted and foliage may fall off. The best control is to remove plants from the soil, wash the roots and re-pot in sterilized soil.
Mealy bugs are tiny, white insects that look like tufts of lint.
Bad infestations will cause stunted growth and eventually kill the plant. They're found on the underside of leaves and where the leaves branch off from the main stem of the plant. Use the same controls as for aphids. Mites are generally too small to be seen without a magnifying glass. They are brownish in color and look like dust.