Brown soft scale

The brown soft scale (Coccus hesperidum) is a significant pest belonging to the order Hemiptera and the family Coccidae. It is a cosmopolitan species frequently encountered in greenhouses, nurseries, and warm outdoor climates.

This pest affects a vast array of ornamental and economic crops, with a strong preference for citrus species, ferns, ivy, ficus, and laurel. The insects are often found clustering along the midribs of leaves and on tender green stems.

The biological cycle of this species is notable for its parthenogenic and viviparous reproduction. Adult females are sedentary and protect their offspring beneath their flattened, leathery bodies. Only the first instar nymphs, known as crawlers, are mobile and responsible for spreading the infestation to other parts of the plant.

The damage is caused by the extraction of large amounts of phloem sap. This feeding process drains the plant of vital nutrients, resulting in stunted growth and chlorosis. Furthermore, the excretion of honeydew promotes the growth of sooty mold, which impairs photosynthesis by covering the leaf surface with a dark, sticky film.

Management strategies require a combination of cultural and chemical controls. Effective methods include:

• Pruning and destroying heavily infested plant parts.
• Applying horticultural oils or soaps to suffocate the insects.
• Using systemic insecticides for severe infestations, targeting the crawler stage.
• Encouraging natural predators such as parasitoid wasps (e.g., Metaphycus helvolus) in greenhouse settings.