Glassy-winged sharpshooter

Appearance

These sharpshooters are about 12 millimetres in length. Their color is dark brown to black with black-and-yellow undersides, with yellow eyes, and the upper parts of the head and back are speckled with ivory or yellowish spots. The wings are transparent with reddish veins.

They have piercing, sucking mouthparts and rows of fine spines on their hind legs.

Distribution

It is native to North America, but it was accidentally introduced into Southern California in the early 1990s, probably with ornamental or agricultural stock. There it has become an agricultural pest especially to viticulture.

Glassy-winged sharpshooters usually lay a mass of eggs on the underside of leaves, and they cover them with powdery white protective secretions kept in dry form on the wings. After the nymphs hatch, the remaining egg mass leaves a brown mark on the leaf's surface. The nymphs feed within the vascular system of the small stems on the plant where the eggs were deposited. After several molts, the nymphs become adult glassy-winged sharpshooters.

The glassy-winged sharpshooter feeds on a wide variety of plants. Scientists estimate the host plants for this sharpshooter include over 70 different plant species. Among the hosts are grapes, citrus trees, almonds, stone fruit, and oleanders. Because of the large number of hosts, glassy-winged sharpshooter populations are able to flourish in both agricultural and urban areas. They feed on a plant by inserting their needle-like mouth parts into the plant's xylem. While feeding, sharpshooters squirt small droplets of waste from the anus, often called "leafhopper rain." These droplets are messy and, when the water evaporates, leave a residue that gives plants and fruit a whitewashed appearance.

Their feeding method, along with their voracious appetite for so many different hosts, makes glassy-winged sharpshooters an effective vector for the "Xylella fastidiosa" bacterium. Once the sharpshooter feeds on an infected plant, "X. fastidiosa" colonizes it by forming a biofilm on its mouth-parts. The sharpshooter then transmits the disease to additional plants while feeding. A plant that is not affected by any of the diseases caused by "X. fastidiosa" becomes a reservoir, holding the bacterium for other sharpshooters to pick up and carry to other plants. "X. fastidiosa" is linked to many plant diseases, including phoney peach disease in the southern United States, oleander leaf scorch and Pierce's disease in California, and citrus X disease in Brazil.