Woolly whitefly

Type Description

"Egg
The eggs are bean-shaped and are found on the undersurface of the leaves with the hollow area directed upwards. When first laid, they are dark brown-black in color and covered with white waxy secretion from the adult. The edges are darker than the center. They differ from other whitefly species in that they lay their eggs en masse and in a regular circular pattern.


Nymph
After hatching, the first stage nymphs are quite transparent and shiny in appearance, then yellowish in color. The newly emerged nymphs are mobile for about 20 minutes, after which they are fixed to the undersides of the leaves. The developing nymphs secrete a white waxy powder. Wingless nymphs are green at first, then turn brown.

Pupa
The pupal stage is characterized by tooth-shaped extensions of the body. It is larger and darker than the other stages. It secretes a cottony honey-like substance. It has abundant white appendages on the body margin in the form of cotton fibers extending outwards.

Adult
Adult females are about 1.5 mm long, with a yellowish-white body and wings covered with white waxy dust. The head is triangular. Adult males are similar in appearance to females. They are about 1 mm long."

Habitat

"It lives mainly in broad-leaved deciduous woodlands, including citrus and guava plants. The pest originated in Asia and spread first to Central and North America and then to the Mediterranean region. In the Mediterranean region, it was first detected in the Canary Islands (1959) and later in Spain and France (1969). It was detected in Italy in 1970, Morocco in 1972, Sicily in 1980 and Algeria in 1982. It has been found in Portugal, Israel and Tunisia, and even in the UK in greenhouses where ornamental plants of the Citrus genus are grown.

In Turkey, there are records from the Eastern Mediterranean Region (Ulusoy et al. 2003), Hatay (Teeli and Yiğit, 2012) and Antalya (Göl and Karaca, 2016)."

Reproductive Information

The eggs are laid in circles or semicircles on the undersides of the leaves. The female inserts her mouthparts into the lower leaf and turns as she lays eggs. The newly hatched young move a short distance before they start to eat. The fourth instar 'pupa' stops feeding and undergoes metamorphosis. Winged adults are the main dispersal stage.

Lifecycle

"The citrus cotton whitefly places its eggs, which are usually laid in a circle or semi-circle, on the underside of young, fully expanded leaves, usually located in the inner regions of trees. In the Mediterranean region, the pest completes 5-6 annual generations, with numbers peaking in mid-summer.

Eggs
Nymph
Pupa
Adult"

Nutrition Information

The Citrus Cotton Whitefly sucks the phloem sap and causes wilting and dropping of leaves when populations are large. The sap droplets collect dust and promote sooty mold growth. Large infestations where abundant sap is produced can cause entire trees to blacken. This reduces photosynthesis and leads to reduced fruit size. Pith and sooty mold can also contaminate the fruit. Although this contamination can be washed away in the packing shed, it slows down the harvest in infested orchards.

General Impact Information

The damage caused by the citrus cottony whitefly on citrus fruits is mostly due to the ball-like substance secreted intensively by the nymphs. These substances form fumagin and provide a food source for fungi that prevent photosynthesis of the plant. In intense damage, the leaves turn black and white.

General Management Information

The pest can be easily suppressed by its natural enemies in nature. The most important natural enemy is Cales noacki (Howard).

General Pathway Information

It is spread by commercial dispersal of its host plants. It is spread by commercial dispersal of its host plants.

Notes

The species has no specified use in the literature.

References