Scale insect is particularly tricky to eliminate as the adults form hard waxy shells that act as a protective armour. Worse still, on indoor plants the environment allows them to continue reproducing all year round. The key thing to remember with scale insects is that they are relatively immobile, so infestations are normally brought in when new plants are introduced. This can be avoided by giving all new plants a thorough inspection, regardless of how reputable the supplier is! Use a magnifying glass and check every part of the plant. Scale insect occurs on all parts, so check the stems as well as the leaves. It is best to quarantine any new plants on a different windowsill for a month to check that they are not carrying scale insects. The moment a problem is suspected remove the plant to prevent scale insects from spreading. To combat the current problem on the cyclamen, use different methods for the adults and the juveniles. Scrape the adults off of the plant with your thumb nail and wipe the foliage and stems gently with a cloth dipped in soapy water. Chemicals are most effective on the crawlers (juvenile forms) as they are more vulnerable before they develop a hard shell. Make a repeat application two weeks later in order to catch any missed ones from first time. Spray the underside of the leaves and the stems too. It is worth knowing that the dead adults do not drop off of the plant which makes it difficult to spot new infestations.