Glassy-winged sharpshooter
Encyclopedia
The glassy-winged sharpshooter (Homalodisca vitripennis, formerly known as H. coagulata) is a large leafhopper
insect from the family Cicadellidae, similar to other species of sharpshooter
.
These sharpshooters are about 12 millimetre (0.47244094488189 in) 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.
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
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
s, citrus
trees, almond
s, stone fruit, and oleander
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
. While feeding, sharpshooters squirt small droplets of waste from the anus (filtered xylem fluid, basically water with trace solutes, especially carbohydrate
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
bacterium. Once they feed on an infected plant, X. fastidiosa colonizes the sharpshooter by forming a biofilm
on its mouth-partshttp://nature.berkeley.edu/~rodrigo/Lab%20page/papers/Almeida06.pdf. The sharpshooter then transmit 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.
(IPM) of the glassy-winged sharpshooter include the use of insecticides, parasitoid
s (especially wasps in the family Mymaridae), 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
), 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), 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.
Leafhopper
Leafhopper is a common name applied to any species from the family Cicadellidae. Leafhoppers, colloquially known as hoppers, are minute plant-feeding insects in the superfamily Membracoidea in the order Hemiptera...
insect from the family Cicadellidae, similar to other species of sharpshooter
Sharpshooter (insect)
The name sharpshooter is used to refer to any of various genera and species of large leafhoppers in the tribe Proconiini of the family Cicadellidae. As with all cicadellids, they have piercing-sucking mouthparts and closely spaced rows of fine spines on their hind legs...
.
Description
They have piercing, sucking mouthparts and rows of fine spines on their hind legs.
Distribution
It is native to North America (northeastern Mexico), but has spread into the United States, where it has become an agricultural pest.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
Brochosome
Brochosomes are intricately structured microscopic granules secreted by leafhoppers and typically found on their body surface and, more rarely, eggs. Brochosomes were first described in 1952 with the aid of an electron microscope...
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
Ecdysis
Ecdysis is the moulting of the cuticula in many invertebrates. This process of moulting is the defining feature of the clade Ecdysozoa, comprising the arthropods, nematodes, velvet worms, horsehair worms, rotifers, tardigrades and Cephalorhyncha...
, 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
Grape
A grape is a non-climacteric fruit, specifically a berry, that grows on the perennial and deciduous woody vines of the genus Vitis. Grapes can be eaten raw or they can be used for making jam, juice, jelly, vinegar, wine, grape seed extracts, raisins, molasses and grape seed oil. Grapes are also...
s, citrus
Citrus
Citrus is a common term and genus of flowering plants in the rue family, Rutaceae. Citrus is believed to have originated in the part of Southeast Asia bordered by Northeastern India, Myanmar and the Yunnan province of China...
trees, almond
Almond
The almond , is a species of tree native to the Middle East and South Asia. Almond is also the name of the edible and widely cultivated seed of this tree...
s, stone fruit, and oleander
Oleander
Nerium oleander is an evergreen shrub or small tree in the dogbane family Apocynaceae, toxic in all its parts. It is the only species currently classified in the genus Nerium. It is most commonly known as oleander, from its superficial resemblance to the unrelated olive Olea, but has many other...
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
Xylem is one of the two types of transport tissue in vascular plants. . The word xylem is derived from the Classical Greek word ξυλον , meaning "wood"; the best-known xylem tissue is wood, though it is found throughout the plant...
. While feeding, sharpshooters squirt small droplets of waste from the anus (filtered xylem fluid, basically water with trace solutes, especially carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...
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
Xylella fastidiosa, a bacterium in the class Gammaproteobacteria, is an important plant pathogen that causes phoney peach disease in the southern United States, oleander leaf scorch, and Pierce's disease, and citrus variegated chlorosis disease in Brazil.-Pierce's disease:Pierce's disease was...
bacterium. Once they feed on an infected plant, X. fastidiosa colonizes the sharpshooter by forming a biofilm
Biofilm
A biofilm is an aggregate of microorganisms in which cells adhere to each other on a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric substance...
on its mouth-partshttp://nature.berkeley.edu/~rodrigo/Lab%20page/papers/Almeida06.pdf. The sharpshooter then transmit 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 managementIntegrated Pest Management
Integrated pest management is an ecological approach to agricultural pest control that integrates pesticides/herbicides into a management system incorporating a range of practices for economic control of a pest...
(IPM) of the glassy-winged sharpshooter include the use of insecticides, parasitoid
Parasitoid
A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host organism in a relationship that is in essence parasitic; unlike a true parasite, however, it ultimately sterilises or kills, and sometimes consumes, the host...
s (especially wasps in the family Mymaridae), 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
The Dicistroviridae are a family of Group IV insect-infecting viruses. Some of the insects commonly infected by dicistroviruses include aphids, leafhoppers, flies, bees, ants, silkworms.-Taxonomy:...
), 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), 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.
Further reading
- Grandgirard, J., M.S. Hoddle, G.K. Roderick, J.N. Petit, D. Percy, R. Putoa, C. Garnier, and N. Davies. 2006. Invasion of French Polynesia by the Glassy-Winged Sharpshooter, Homalodisca coagulata (Hemiptera: Cicadellidae): A New Threat to the South Pacific. Pacific Science, 60:4, 429-438.
- Hoddle M.S., Grandgirard J., Petit J., Roderick G.K., Davies N., 2006. Glassy-winged sharpshooter Ko'ed - First round - in French Polynesia. Biocontrol News and Information 27(3), 47N-62N
External links
- PIPRA - Pierce's Disease Website
- University of California GWSS Workgroup
- CDFA PD/GWSS Board Interactive Forum
- Organization fighting the potential of infestation in Northern California
- Biocontrol of the GWSS in French Polynesia
- glassy-winged sharpshooter on the University of FloridaUniversity of FloridaThe University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
/ Institute of Food and Agricultural SciencesInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
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 LibraryUnited States National Agricultural LibraryThe United States National Agricultural Library 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...
. Lists general information and resources for Glassy-Winged Sharpshooter.