T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Scale (Hemispherical scale) Saissetia coffeae

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hemiptera
Suborder: Sternorrhyncha
Superfamily: Coccoidea
Family: Coccidae
Genus: Saissetia
Species: S. coffeae
Binominal name: Saissetia coffeae
Common name: Hemispherical scale

Saissetia coffeae is an exotic, adventive, polyphagous species of hemispherical scale. It is a pest of exotic and native plants and is found on their stems and underside of their leaves. It is found in urban plants and within native forests. It is found throughout the North Island and most of the South Island.

The body of adult female is 2-3 mm long, hemispherical, hard, shiny, red-brown shell. Body of immature female is flat, yellow-brown, with three dorsal ridges resembling the letter H, which disappear at maturity.
Saissetia coffeae reproduce by parthenogenesis (no males). The female lays 500-2500 eggs in a cavity beneath her shell. As the female lays her eggs, her body mass shrinks, forming a brood chamber underneath where the eggs hatch into a mass of pinkish-coloured crawlers. The number of generations varies from one to six per year depending on the medium and infected plant. S. coffeae prefers humid and dry environments, but can not grow to more than 30 ° C. be optimal at 28 ° C, cycle lasted 52 days and then produce more eggs.
Colonies of S. coffeae extract large amounts of sap which produces a great weakening of the plant and can attract ants by their secretions.

A video of a Saissetia coffeae shell turned on its back showing it laying eggs. Click image.


Saissetia coffeae in vairies stages of development.


 

Photo of a female turned on her back showing how her body mass has shrunk and has formed into a brood chamber underneath where the eggs have hatch into a mass of pinkish-coloured crawlers.