Conservatory is peculiar ecosystem. When it is in balance there are no troubles. This means, that insects or fungi appear now and then, but they don't do any damage worth mentioning. Therefore we should not use different chemical pest controllers at tiny signs of possible problems. We must keep in mind that plants have their own ways of dealing with pests and diseases. We must take care only of optimal life conditions.
More important than repression is pest and disease prevention which ensures that pests and diseases do not spread. Therefore, we must maintain optimal conditions for the growth of plants all the time. Inadequate temperature causes stress to plants and makes them less resilient. Humidity must be on the right level through the year. When humidity is too low insects and other pests reproduce very fast. When humidity is to high fungi and molds prosper. Plants should be watered and fertilized just right and in summer we should ventilate and shade winter garden.
New plants are the most common source of diseases and pests. Although we thoroughly inspect them before the purchase, it may happen that we oversee pests and diseases. Therefore new plants should be placed in quarantine. Quarantine is a closed place without any other plants where we observe new plants for at least week or two. If problems occur, appropriate action should be taken.
If there is excessive propagation of pests and diseases, we must act. The easiest, but not always the most appropriate way is to use chemical control. However, we should be careful. Chemicals can stay in winter garden for longer time and have negative impact on plants, animals and humans. Therefore, we should seek expert advice which chemicals to use, how to use them and for how long.
Whenever is possible, we should use natural solutions for problems with plants. Different literature offers many advices how to help plants in natural way.