By: Mary H. Dyer, Credentialed Garden Writer
What is a glassy winged sharpshooter? This harmful pest, native to the Southeastern United States and Mexico, is a type of large leafhopper that feeds on fluids in tissues of various plants. Although the pests rarely cause immediate damage, they excrete copious amounts of sticky liquid that hardens on fruit, and also gives foliage a pale, whitewashed appearance. Additionally, the drippy stuff is a big problem when it sticks on cars parked below infested trees. Read on to learn about managing glassy winged sharpshooters and tips on how to prevent transmission of dangerous plant diseases.
Sharpshooter pests in gardens are a real problem for fruit trees and a wide range of plants, including:
Other than the nasty liquid mentioned above, sharpshooter damage consists primarily of transmission of Xylella fastidiosa, a bacterium that causes potentially deadly plant diseases, including several types of leaf scorch and Pierce’s disease of grapes. When a pest feeds on an affected plant, the bacterium multiplies in the pest’s mouth and is transferred when the sharpshooter moves on to feed on a different plant.
Preventing spread of dangerous plant diseases is the reason why careful control of sharpshooter pests in gardens is so critical.
There are a few options for managing glassy winged sharpshooter insects in the garden.
A healthy population of beneficial insects is the single most effective way to control sharpshooters. One of the most effective is a small wasp that feeds on the pest’s egg masses. Praying mantis, assassin bugs and lacewings are also extremely beneficial at managing glassy winged sharpshooters.
Avoid chemicals as long as possible because pesticides can decimate populations of beneficial insects, which means sharpshooters and other pests are free to multiply like crazy. Additionally, pesticides haven’t been proven to be very effective when it comes to controlling spread of bacteria, and in time, pests can build up immunity and control becomes much more difficult.
If you feel pesticides are necessary, talk to your local cooperative extension office to determine which products are more effective – and least harmful to beneficial insects.
Insecticidal soaps and horticultural oils don’t kill the eggs, but they will kill the nymphs and prevent the production of the sticky excrement. However, the substance must come in contact with the pests in order to be effective. Thorough coverage of foliage is necessary and repeat application is required every seven to 10 days.
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San FranciscoState University
Department of Geography
Geography 316: Biogeography
The Biogeography of
Glassy-winged sharpshooter (Homalodisca coagulata )
by Greti Wolf, student in Geography 316, Fall 2000
Homalodisca coagulata, The Glassy-winged Sharpshooter.
Species: Homalodisca coagulata
Description of Species:
Homalodisca coagulata, theGlassy-winged Sharpshooter, is a large (13-24 mm long) dark brown insect. Adultshave small yellow spot marking the head and thorax. The wings are translucent,with red veins, and give the animal its “glassy” appearance. The underside of the abdomen is white.
Homalodisca coagulata are xylem feeders, using their long sharp mouth parts to pierce the surface o ftheir host plants. The xylem is the conductive tissue of the plant, which transports fluids and salts from the roots upwards through the plant (Jones, etal 1992). Homalodisca coagulata is an effective vector of bacterial plant pathogen (Phillips 1999). Homalodisca coagulata belongs to the Family Cicadellidae: the leafhoppers. Leafhoppers are serious pests in cultivated crops, especially citrus orchards and vineyards. Some species of leafhoppers excrete a clear watery fluid from the anus known as "honeydew". This substance attracts other insects that cause further damage to the plant.(Borror 1970).
Originally from the southeastern United States and northern Mexico, Homalodisca coagulata, the Glassy-winged Sharpshooter, has recently spread to California. The insect was first discovered in California in 1990 (in Ventura County). Previous specimens had been collected in 1989, but were not recognized as a seperate species until later. Within two years Glassy-winged Sharpshooters had spread to San Bernardino, Riverside, Los Angeles, Orange, and Santa Barbara Counties. (Phillips 1999). Further infestations have been reported as recently as October 2000, in Sacramento, Butte, and Contra Costa counties. In November 2000, it reached the vineyards of Sonoma County.(CA 2000). Homalodisca coagulata will continue to spread throughout all of California's agricultural regions.
Homalodisca coagulata adults live for only two months. They lay their eggs under the epidermis of host plants. These egg clusters appear as small fluid-filled sacs on the leaves. The eggs hatch within two weeks. Nymphs are small and white. They feed upon the stems of the host plant, destroying it even further. Nymphs under go four molting phases before maturity. Two egg laying phases occur each year in July/August and February/March. (CDFA 2000)
Homalodisca coagulata prefer thick leafy plants. It's original habitat was the low scrub of the Southwest desert areas, but it has easily adapted to the lush agricultural areas of California. orchards and vineyards are now the insects' habitat of choice. The long, evenly spaced rows of continuous vegetation have provided a "highway system" that has facilitated the rapid infestation of sharpshooters throughout the Central Valley.
Insects are among the oldest life forms on the planet. The first arthropods appeared in the Paleozois era, as evidenced by the fossils found in the Burgess Shale of Northern Canada. The Burgess Shale fauna were a varied group axhibiting many variations on the insect from theat survives today. (Briggs et al 1994). Some of these creatures survived mass extinction events at the end of the Cambrian. These went on to evolve into the much larged arthropods of the Mesozoic. Large flying insects appeared during the Permian period. A rapid radiation of all types of arthropods occurred through the Jurassic. Unlike the dinosaurs of the Mesozoic, insects survived the mass extinction event of the Cretaceous and have gone on to become the most populous and widespread fauna on the planet.
Other interesting issues:
Homaladisca coagulata has been identified as a serious threat to California's viticultural regions because it is a known vector of Pierce's Disease, the plant pathogenic bacterium Xylella fastidiosa. Pierce's Disease, once injected by a sharpshooter into a plant, will cause a rapid die-back of foliage and eventual death of the entire plant. Because this could mean disaster to the wine industry early detection of Homalodisca coagulata is very important. Only one biological control has been identified. Gonatocerus ashmeadi Girault is a parasite that attacks the eggs of Homalodisca coagulata. (Phillips 1999). Other measure to avoid complete infestation include spraying vineyards and surrounding agricultural areas, especially citrus. Pierce's Disease also causes Almond Leaf Scorch Disease and Oleander Scorch. Because oleander is found in 20% of all home gardens in California, and is used extesively as an ornamental windbreak along all major highways, the destruction of this plant is of real concern to CalTrans and other public agencies.
Research to prevent the oncoming disaster that Homalodisca coagulata will bring is ongoing at the University of California Riverside, Davis, and Berkeley. Methods for early detection, as well as strategies for control and eradication of this pest are a high priority in the Agri-research field. The American Vineyard Foundation has declared the Glassy-winged Sharpshooter as "Public Enemy # 1"
Borror, Donald J., and Richard E. White.1970. A Field Guide to the Insects. Boston., Massachusetts. Houghton Mifflin Company.
Briggs, Derek E.G., DouglasH. Erwin, and Frederick J. Collier. 1994. The Fossils of the Burgess Shale. Washington and London. SmithsonianInstitution Press.
California Department of Food and Agriculture. 4 August 2000. "Distribution Of Glassy-winged Sharpshooter". [Online] Available: California Homepage. [Online] Available: http://www.cal.gov
California Department of Food and Agriculture. 27 October 2000. "Recent Events". [Online]Available: California Homepage.[Online] Available: http://www.cal.gov
Jones, Gareth, Alan Robertson, Jean Forbes, and Graham Hollier. 1992. TheHarper Collins Dictionary of Environmental Science. New York. HarperCollins.
Aphids, whiteflies, scales and mealybugs are small insects with piercing mouth parts. They congregate on hibiscus leaves in colonies and suck out the plant sap. Aphids and whiteflies are tiny winged insects. Scales look like colored spots on plants. Some are soft while armored scales grow a hard covering to protect themselves. Colonies of mealybugs look like clumps of cotton. Hibiscuses develop spotting and plants stop growing when infested with large colonies of sucking insects. Many of the pests also leave behind sticky waste called honeydew, a host for fungal disease.
Japanese beetles (Popillia japonica) are oval-shaped, metallic-green and copper colored insects, about 1/3 to 1/2 inch long. Larvae feed on roots and grasses but adult Japanese beetles mostly eat leaf tissue, especially when exposed to direct sunlight. Female Japanese beetles lay their eggs in the soil, overwintering deeply into the ground. Eggs hatch, feeding on grass roots. From May to August, Japanese beetles eat crape myrtle flowers and leaf tissue between foliage veins. To control Japanese beetles, you can pick them off by hand or use a water spray, but homemade or commercially available products may be more effective, suggests Clemson University Extension. Traps, containing milky spore (Bacillus popilliae), placed at least 50 feet away from crape myrtle kill larvae but usually not adult Japanese beetles. Effective insecticides for use on crape myrtle may include lambda, permethrin, carbaryl, acephate, cyhalothrin, neem oil, cyfluthrin or inidacloprid -- the types and amounts of products to use depend on your growing landscape. Strong insecticides may kill natural predators of Japanese beetles.
A: Only leaves and stems! They have a beak-like mouth that will bite into a leaf and enable them to suck the plant sap out of it. They don’t like the taste of animals, though, so you’re spared from being bitten by this bug.
A: There are really leafhoppers for almost every type of plant. Those which prey on tobacco also tend to favor tomatoes, eggplants, and peppers, and they can transmit the tobacco mosaic virus to your tomatoes. There’s also leafhoppers that favor ornamental plants, such as rose leafhoppers.
Have you found the right way to evict the lurking leafhoppers from your yard yet? What sort of leafhoppers are major problems in your area? Tell everyone your pest woes in the comments below!