The glassy-winged sharpshooter (''Homalodisca vitripennis'', formerly known as ''H. coagulata'') is a large leafhopper (family Cicadellidae), similar to other species of

sharpshooter A sharpshooter is one who is highly proficient at firing firearms or other projectile weapons accurately. Military units composed of sharpshooters were important factors in 19th-century combat. Along with " marksman" and "expert", "sharpshooter" ...

Description

These sharpshooters are about 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.APHIS. 2002
Glassy-winged Sharpshooter and Pierce's Disease in California
They have piercing, sucking mouthparts and rows of fine spines on their hind legs.

Distribution

It is native to North America (northeastern Mexico), 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 (called "

brochosome Brochosomes are intricately structured microscopic granules secreted by leafhoppers (the family Cicadellidae of the insect order Hemiptera) and typically found on their body surface and, more rarely, eggs. Brochosomes were first described in 1 ...

s") 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

grape A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus '' Vitis''. Grapes are a non- climacteric type of fruit, generally occurring in clusters. The cultivation of grapes began perhaps 8,000 years a ...

citrus ''Citrus'' is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is native to ...

trees, almonds,

stone fruit In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part ( exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or ''pyrena'') of hardened endocarp with a seed (''kernel' ...

, and

oleander ''Nerium oleander'' ( ), most commonly known as oleander or nerium, is a shrub or small tree cultivated worldwide in temperate and subtropical areas as an ornamental and landscaping plant. It is the only species currently classified in the ge ...

s. 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 Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from ...

. While feeding, sharpshooters squirt small droplets of waste from the anus (filtered xylem fluid, basically water with trace solutes, especially

carbohydrate In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or m ...

s), 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 ''Xylella fastidiosa'' is an aerobic, Gram-negative bacterium of the genus ''Xylella''. It is a plant pathogen, that grows in the water transport tissues of plants ( xylem vessels) and is transmitted exclusively by xylem sap-feeding insects such ...

'' bacterium. Once the sharpshooter feeds on an infected plant, ''X. fastidiosa'' colonizes it by forming a

biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular ...

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.

Management

Successful efforts using

integrated pest management Integrated pest management (IPM), also known as integrated pest control (IPC) is a broad-based approach that integrates both chemical and non-chemical practices for economic control of pests. IPM aims to suppress pest populations below the econ ...

(IPM) of the glassy-winged sharpshooter include the use of insecticides, parasitoids (especially wasps in the family

Mymaridae The Mymaridae, commonly known as fairyflies or fairy wasps, are a family of chalcidoid wasps found in temperate and tropical regions throughout the world. The family contains around 100 genera with 1400 species. Fairyflies are very tiny insects ...

), and the impact of naturally occurring pathogens like viruses, bacteria, and fungi. One of the newly discovered pathogens is a virus specific to sharpshooters. The leafhopper-infecting virus, '' Homalodisca coagulata virus-1'' (HoCV-1, ''

Dicistroviridae ''Dicistroviridae'' is a family of viruses in the order ''Picornavirales''. Invertebrates, including aphids, leafhoppers, flies, bees, ants, and silkworms, serve as natural hosts. There are 15 species in this family, assigned to three genera. Di ...

''), has been shown to increase leafhopper mortality. The virus occurs in nature and is spread most readily at high population densities through contact among infected individuals, contact with virus-contaminated surfaces, and/or as an aerosol in leafhopper excreta. One of the most successful biocontrol efforts has been the mass rearing and release of four different leafhopper parasitoids (in the mymarid genus ''

Gonatocerus ''Gonatocerus'' is a genus of fairyflies in the family Mymaridae. There are at least 260 described species in ''Gonatocerus''. See also * List of Gonatocerus species This is a list of 262 species in ''Gonatocerus'', a genus of fairyflies in th ...

''), which have been very successful in reducing the number of eggs that survive. The traditional means of insect management, such as scouting and land owner reports of leafhopper presence, followed by highly focused insecticide treatments, have also been of great value in reducing leafhopper numbers; all of these impacts have produced a system wherein reasonable, environmentally sound management of this insect pest is being maintained.

References

External links

PIPRA - Pierce's Disease Website

CDFA PD/GWSS Board Interactive Forum

* ttps://web.archive.org/web/20070311133816/http://gwss.mooreascience.org/ Biocontrol of the GWSS in French Polynesia
glassy-winged sharpshooter
on the

University of Florida The University of Florida (Florida or UF) is a public land-grant research university in Gainesville, Florida. It is a senior member of the State University System of Florida, traces its origins to 1853, and has operated continuously on its ...

/ Institute of Food and Agricultural Sciences ''Featured Creatures'' website
CISR - Glassy-Winged Sharpshooter Fact Sheet with photos

Species Profile - Glassy-Winged Sharpshooter (''Homalodisca coagulata'')
National Invasive Species Information Center,

United States National Agricultural Library The United States National Agricultural Library (NAL) is one of the world's largest agricultural research libraries, and serves as a national library of the United States and as the library of the United States Department of Agriculture. Located ...

. Lists general information and resources for Glassy-Winged Sharpshooter. {{Taxonbar, from=Q280362 Proconiini Hemiptera of North America Insect vectors of plant pathogens Agricultural pest insects Insects described in 1821

Description

Distribution

Management

References

Further reading

External links