The brown soft scale Coccus hesperidum is very common in tropical and sub-tropical regions and is also a common pest in greenhouses throughout the world. C. hesperidum has many host plants, including sub-tropical fruit crops (citrus, papaya, etc.) and ornamentals such as schefflera, ficus, hibiscus, oleander, palms, ferns and orchids.
Life cycle and appearance of Brown soft scale
The scale of the female is flat, usually an elongated oval shape, 3-4 mm long, yellow-green or light grey in colour, with dark brown speckles or spots. The colour of the scale darkens as the female ages. The size, shape and characteristics of the female also vary with different host plants. The middle of the scale is always darker than the margins.
Females reproduce parthenogenetically (without mating). It may appear that they bear live young, but in fact the first instar nymph emerges from the egg under the mother’s scale.
The pink crawlers are active for two or three days and disperse locally before settling. Once fixed in position, their colour changes to a transparent, light brown and they begin to feed.
The scales produce enormous quantities of honeydew. This is usually the first visible symptom. Because of this, C. hesperidum is often attended by ants. The ants will clean and protect the coccids and in turn benefit from a rich food source. The honeydew also quickly becomes infected by sooty moulds which can cover the leaves, flowers and fruit of the host and reduce photosynthesis and respiration.