The Situation: Arundo donax, also known as giant reed or arundo, is native to Eastern Asia but has been widely planted around the world because this plant has a variety of practical uses. Arundo has been used for walking sticks, fishing poles, musical instruments, and recently it is being investigated as a biofuel source. Arundo...
The Situation: Didymo or rock snot, is a highly invasive species of freshwater diatom that can form large and extensive mats in rivers, streams, and lakes. Didymo is native to cool temperate areas of the northern Hemisphere including Europe, North America, and Asia. In 2004, didymo was discovered infesting freshwater rivers in the South Island...
The Situation: In 2002 , a non-native insect, the redbay ambrosia beetle, Xyleborus glabratus (Coleoptera: Scolytidae), was first detected in the United States near Port Wentworth, Georgia. The beetle was likely introduced in untreated wooden packing material, such as crates and pallets, imported through the shipment of goods from its native range in southeast Asia...
The Situation: Africanized honey bees (AHB) are a hybrid between European and African bee subspecies which were inadvertently released in Brazil in the 1950s. They have spread to the south as far as northern Argentina and to the north into the United States, as well as throughout much of South and Central America. They entered...
The Situation: Ash whitefly represents an outstanding biological control success in California. Ash whitefly was first introduced into California in the late 1980s and was a significant pest of fruit and shade trees such as ash, pear and pomegranate. In the absence of natural enemies, ash whitefly populations exploded out of control. The pest originated...
The Situation: The Asian tiger mosquito entered the United States in shipments of used tires from northern Asia in the mid-1980s. It can survive in a broad range of climates and has spread rapidly from the point of first detection in the south-central United States. Prior to its successful invasion of the southeastern U.S., isolated...
The Situation: Originating in Asia, the citrus leafminer (CLM) was first discovered in Florida in 1993. These small moths rapidly became a significant pest, with infestation rates of up to 90% in some areas in Florida being observed within the year of introduction. By 1995, the citrus leafminer was discovered in Texas, Central America, western...
The Situation: The giant whitefly, a pest of over 50 common ornamental plants, was discovered in southern San Diego County in 1992. It continues to extend its range northward into California where it was found around San Luis Obispo on the central Coast by the late 1990’s, and by around 2005 this pest was established...
The goldspotted oak borer (GSOB) was first detected in 2004 in San Diego Co., California by the California Department of Food and Agriculture during a survey for exotic woodborers. In 2008, it was found in the same county attacking coast live oak, Quercus agrifolia, canyon live oak, Q. chrysolepis, and California black oak, Q. kelloggii...
The Situation: A new biotype of the pea leafminer was introduced in Northern California and is expanding rapidly into Central and Southern California. Already this insect has become a major pest of vegetable crops from Monterey to Ventura Counties. It has spread as far north as Placer County and as far south as Las Vegas...
The Situation: Red gum lerp psyllid is an insect that is native to Australia. In June 1998, this insect invaded California and was first found in Los Angeles County. This pest feeds exclusively on species of Eucalyptus and in California it exhibits high preference for river red gum ( Eucalyptus camaldulensis), flooded gum ( E...
The Situation: Russian thistle, commonly known as tumbleweed, is a profusely branched annual herb. Its efficient taproot, abundant seed production and reduced leaf surface adapt this weed well to disturbed semiarid agricultural environments, rangeland and nonagricultural areas such as vacant resident lots and railroad or highway rights-of-way. It has become pervasive as an exotic weed...
Damage: Once established, saltcedar is tolerant to high salinity and secretes salt at a high rate which is deposited on the soil surface to the detriment of native plant species. Saltcedar increases fire frequency within the riparian habitats it dominates because of its high levels of dead leaves and branches that provide fuel for fires...
The Situation: When the silverleaf whitefly (SLW) (also known as Bemisia tabaci strain B) struck southern California’s desert valleys in fall 1991, clouds of these tiny insects could be seen moving across the region, which produces 90 percent of the fall and winter vegetables grown in the U.S. Research conducted at the University of California...
The Situation: The Sting nematode is an important pathogen on most agricultural and horticultural crops, including turf, citrus and grapes. This ectoparasite is native to sandy soils in the southeastern and Midwestern United States. In 1992, UC Riverside nematologists discovered that several golf courses in the Coachella Valley were heavily infested with sting nematodes. The...
The Situation: In southern California, the native western flower thrips (WFT) Frankliniella occidentalis is the most common vector responsible for transmission of an exotic plant virus, Tomato Spotted Wilt Virus (TSWV). The pathogen was discovered on tomatoes in 1915 in Australia, and has been spreading around the world ever since. TSWV is a tospovirus (Bunyaviridae)...
The Situation: The Asian Woolly Hackberry aphid Shivaphis celtiwas first detected in North America on native hackberry trees ( Celtis occidentalis) in Georgia in 1996 and has been subsequently found throughout the southeastern states. In 2002 the aphid was detected in several counties in the San Joaquin Valley of California on the commonly planted Chinese...
The Situation: Eucalyptus is a ubiquitous landscape, shade, and windbreak tree throughout southern and central California. The trees are valued for their fast growth and tolerance of poor soils and drought. Eucalyptus is now threatened by several pest insects accidentally introduced into California from Australia, one of which is the Australian gum tree weevil. Description...
The Situation: Avocado lace bug, Pseudacysta perseae, was first described in Florida in 1908 from specimens collected in this state over the period 1897-1907. Avocado lace bug is a true bug with sucking mouth parts. The common name “lace bug”, is derived from the highly reticulate “lace-like-patterning” of the thorax and wings of adults. There...
The Situation: Avocados are subtropical perennial fruit trees 6-10 meters in height. California produces 95% of the nation’s crop, and 85% of this harvest is from one cultivar, the black fruit Hass avocado. Annually, 6,000 growers in California produce 260 million pounds of fruit on 65,000 acres, and the harvest in 2007 was worth $245...
