Leaves that have been attacked by caterpillars are normally quite severely damaged.  The leaf will be eaten in virtually all areas.  The caterpillar may also weave the tips of leaves together using a fine silken web, where it then feeds in relative safety.  Spray infected plants with a systemic insecticide following manufacturers guidelines. Individual caterpillars, if spotted, can be removed by hand and destroyed.  Some caterpillars feed on specific plants and will not present no problem to fuchsia’s and pelargoniums.  Others, such as the Tortrix moth will feed on just about any plant that they reach - these may be seen in early summer hanging from trees and shrubs on thin silk lines.

Red spider mite, Tetranychus urticae, is a serious problem in hot dry weather, although I am sure they are adapting and have wet suits! The first signs of an attack by this pest will be faint bronzing or mottling of the upper leaf surface (shown on the lower two leaves). On inspection of the underside of the leaf  (top two leaves) you will find a yellowish grey discolouration and tiny black and white speckles - which looks almost like pepper.  If you use a magnifying glass you will be able to see these minute pests.  In severe attacks the leaves will shrivel and dry and the plant will eventually succumb.  There will also be a fine web network noticeable on the plant.  When first detected plants should be sprayed with a systemic or contact insecticide and damaged leaves removed and burnt - or disposed of in the dustbin.  Misting and watering of the plants and staging in greenhouses also helps to keep their numbers down.  The underside of the leaves, where this pest lives and breeds, must be sprayed - not always possible if plants are in a border or near to a pond.  There is another mite which is a natural predator, Phytoseuilus persimilis, which can be used in controlled environments such as a greenhouse. Not easy to eradicate as the mite soon builds up resistance to pesticides - which need to be rotated on a regular basis.

Capsid bugs belong to the order of Hemiptera and the sub-order of Heteroptera and are likely to attack plants growing in the garden. They have two different types of wings and stabbing mouthparts. Their damage is restricted to distortion of immature growing tips, which results in blind growth preventing the formation of flowers. They are a species closely related to leaf hoppers.  Over two hundred species of capsid exist in the British Isles alone.  The common green capsid, Lygacaris pubulinus, attacks many different plants including fuchsia's.  Spray plants with a commercial insecticide following the maufacturers guidelines, remove any distorted or damaged leaves.

Another very serious disease that affects both fuchsia's and pelargoniums is rust - although fuchsia rust will not affect pelargoniums and vice versa.  Fuchsia rust, Pucciniastrum epilobii, will normally be acquired when purchasing new stock where plants have been kept in close proximity to each other and will spread rapidly unless treated.  Fuchsia rust can be found growing on the native wild flower rose-bay willow herb and if this plant grows near to your garden it should be destroyed to stop rust being spread to your plants.  The first signs that you may have rust will be leaves that have a pale brown or reddish  marking, or blotchiness.  On inspection of the underside of the leave the yellowish/orange pustules, which are the spores, will be clearly seen.  All infected leaves should be carefully removed, burnt or placed in a sealed bag and put in the dustbin.  The spores can be easily transported by insects, wind or you fingers whilst inspecting infected plants.  Spray the leaves and soil with a systemic fungicide such as Dithane 945 or Systhane.  Unfortunately, due to many changes enforced by the EU, many of the fungicides that were in common use have now been withdrawn.