Cottony scale

Cottony scale (Chloropulvinaria) belongs to the soft scale family (Coccidae) within the order Hemiptera. These dangerous sap-sucking pests are characterized by the production of white, cotton-like ovisacs that protect their egg clutches. The genus includes several dozen species, with the citrus cottony scale being one of the most economically significant members.

This pest infests a wide range of crops, including subtropical and ornamental plants. It most commonly affects citrus, fig trees, grapevines, laurel, camellia, gardenia, and various greenhouse plants. Under favorable conditions, such as high humidity and a lack of natural enemies, these insects can rapidly colonize and weaken their host plants.

The life cycle of the pest involves several stages: egg, crawler (nymph), and adult. Adult females remain sessile once they attach themselves to stems or the undersides of leaves. Overwintering typically occurs in the second or third nymphal stage, and active reproduction begins in the spring, marked by the emergence of distinct, fluffy ovisacs.

The primary damage results from the continuous extraction of plant sap, which depletes the host. Furthermore, cottony scales excrete honeydew, a sticky substance that promotes the growth of sooty mold. This layer blocks sunlight, disrupts photosynthesis, and leads to yellowing leaves, premature leaf drop, stunted shoot growth, and significantly reduced harvest yields.

Control methods require a multi-faceted approach: the use of systemic insecticides, applications of mineral oil sprays during the crawler stage, and cultural practices. It is crucial to perform timely sanitary pruning of infested branches and to manage ant populations, as ants often protect scale colonies from natural predators and parasitoids.

• Regular monitoring of foliage health
• Application of systemic insecticides during crawler activity
• Cleaning of trunks and branches from loose bark
• Utilization of biological control agents (parasitic wasps)