The black olive scale is a small insect from the Coccidae family. It is parthenogenetic. It develops one generation annually; in warm climates, it can have two biological cycles.

The adult measures 2 to 4 mm in length, 1 to 4 mm in width, and 2 to 2.5 mm in thickness. It has a convex, semicircular, "turtle-like," chitinous shell. As they age, they change color from brown to almost black.

The adult female is identified by its dark shell on the new shoots of the plant. The female dies in September and October, leaving her body full of eggs with shells (about 2,500). The egg-laying occurs from May to August, and they spend the winter attached to the host plant.

The larvae are similar to the adult, changing from orange to light brown and reaching a size of 1.5 mm. They are found on the underside of the leaves. They can be spread by the wind. There are three larval forms.

They feed on the sap of the host plants. The adult female causes direct damage. The larvae secrete a honeydew that facilitates the development of a fungus (sooty mold). This covers the green parts (leaves and young shoots), suffocating photosynthetic activity and causing aesthetic damage.

It is a typical pest that appears on plants under strong stress and weakness; its presence further exacerbates the weakness, affecting and reducing growth, sprouting, and fruit production.

It is a polyphagous pest; it is common on olive trees (Olea) and citrus (Citrus); it also attacks other fruit trees, such as persimmon (Dyospiros), pomegranate (Punica), medlar (Mespilus), fig (Ficus), and various ornamental plants (Cycas, Euonymus, Laurus, Nerium, Pittosporum, etc.).

Compiled by: Manuel Godoy

Bibliography

Metcalf C. and W. Flint. 1974. Destructive insects and beneficial insects. CECSA.

External links

http://fr.wikipedia.org/wiki/Cochenille_noire_de_l´olivier

http://WWW7.INRA.fr/hyppz/RAVAGEUR/3saiole.htm