Insecta, Homoptera, Margarodidae .
Description, Biology, Life Cycle, Damage, Common Names, Images
- This scale insect is polyphagous, with a prediliction for Citrus, Pittosporum, broom (Genista), acacias, false acacia (Robinia), etc. It may also attack herbaceous plants.
- Hermaphrodite species; the female is capable of self-fertilization. Fertilized eggs produce females.
Unfertilized eggs produce males. The latter are rare and have little or no role in reproduction.
- Each female lays 600 to 800 eggs.
- The life-cycle lasts a minimum of 3 months.
The fluted scale produces 2 or 3 generations each year. Overwintering occurs in all instars, but mostly as an N3 nymph. Starting in February, each female may lay 400 to 800 eggs, on Citrus or other evergreen plants. Later hatchings (and the corresponding "waves " of mobile nymphs) occur in June and September.
- Damage caused by this scale insect is always very severe in the case of major infestation: sucking of sap, bark lesions, deformity and weeping constitute direct damage; the abundant production of honeydew on which sooty moulds develop (indirect damage) aggravates the situation.
Because it has no enemies, this scale insect develops on Citrus fruit trees and gives them the appearance of being covered with snow (*) . Production is gravely affected and the trees die.
Originating from Australia, this species has spread through all tropical and subtropical regions and glasshouses in colder countries. It appeared in California in 1868, and shortly before 1900 (date when it was reported from Naples) in Portugal.
Acclimatization of the Australian ladybird Rodolia (Novius) cardinalis (*) to the United States, then Europe and North Africa gave the first and most famous success in biological control. Since then, Icerya purchasi has rarely been seen to be deleterious.
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.