Blue Gum Psyllid: Appearance, Territory, Damage, and Life Cycle

Latin Name: Ctenarytaina Eucalypti

Appearance: Ctenarytaina eucalypti Maskell is a little sucking insect that feeds on eucalyptus trees such as blue gum (Eucalyptus globulus) and mountain gum (Eucalyptus pulverulenta). The blue gum tree the psyllid is found in Australia and feeds on blue gum, Eucalyptus globulus, and other Eucalyptus species with waxy blue juvenile leaves. Eucalyptus pulverulenta, a good host for this pest, has been planted in plantations along with California’s coastal counties. Its foliage is employed in flower arrangements by the florist industry. During the two to three years after the psyllid became entrenched, growers used significant amounts of insecticides to prevent leaf damage.

Hosts Plants: The bug can be found on a wide variety of Eucalyptus species. However, it prefers blue gum species, such as E. globulus and E. nitens.

Territory: This bug, which was mistakenly brought from Australia, has spread throughout New Zealand. It was first mentioned in this city in 1889.

Damage Insect Cause: Blue-gum psyllids concentrate on buds and growing shoots of some eucalypts and cause deformation, withering, and occasionally death of young leaves by sucking sap. Twigs and branches are not harmed, although young plants may become stunted as a result of leaf loss.

Excess sap sugars are excreted by the insects as thin droplets of a sweet sticky solution known as honeydew, and the soot fungus that grow on it gives badly infected plants a blackish look. The threads of a white waxy fluid are exuded by all nymphal stages. The presence of blue-gum psyllids is indicated by a loose cottony mass of broken dispersed filaments.

The light brown remnants of people murdered by the minute parasite wasp Psyllaephagus pilosus Noyes are commonly seen among blue-gum psyllid colonies. Ladybird beetles and lacewings are other predatory agents.

Cleobora mellyi Mulsant, a Tasmanian ladybird that eats the eggs of the eucalyptus tortoise beetle Paropsis charybdis, was recently released in New Zealand and is already established in at least some regions. Because this ladybird and her larvae consume psyllids, it might prey on the blue-gum psyllid. Because the harm caused by this insect appears to be little, no attempt has been made to control it using pesticides.

Life History and Habits: The blue gum psyllid has four or more generations every year. Adults are gray with orange stripes on their bellies and are aggressive flyers. There are five instars, each with a distinctive pattern of orange, brown, and gray markings.

Females lay yellow eggs in clusters near the base of terminal leaves and axial buds. The nymphs hatch and settle on the leaf or stem near the egg clusters to feed. Feeding produces acute harm, such as the suppression of new shoot production and the deformation of new leaf morphology. The nymphs emit wax-coated honeydew spheres as well as enormous quantities of sticky filament that can hide them. Sooty mold developing on honeydew destroys the visual attractiveness of the leaves in floral arrangements, in addition to ugly leaf deformation.