Pest Management
Pests that originate outside of the United States but find their ways here in cars, planes and boats have no natural predators to keep populations in check. These non-native, invasive pests can multiply virtually uncontrolled, wreaking havoc on plants that have no natural defense against these foreigners.
Experts believe that the best and least expensive method of managing and controlling invasive pests is to keep pests out of our ecosystem. This is such a herculean task that it requires multi-agency cooperation: from U.S. Customs and Border Protection agents inspecting international baggage and shipments at airports and border crossings, to the California Department of Food and Agriculture’s border protection stations on major highways entering the state, to the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service’s plant inspection stations located at major international airports and seaports and at major crossings along the U.S.-Mexico and Canadian borders.
Although these agencies are effective at keeping most pests from ever entering California, sometimes a pest sneaks through. When that happens, the focus shifts to controlling and reducing the pest’s presence.
The goal of pest management for invasive species is to control the pest and ultimately to eliminate it. It’s important to control invasive pests quickly because rapid reproduction means their numbers quickly increase, enabling them to spread swiftly to affect larger geographic areas.
The first step in pest management is figuring out where the pest is and if the number of pests is increasing to the level of an infestation. State departments of agriculture conduct surveys, trapping and tracking pests, to monitor pest populations. Sticky traps hung in trees and on plants are effective in measuring pest populations and are often the first step to determine the extent of the pest infestation. The trapped pests are then identified by scientists and an action plan is adopted when the numbers reach a threshold level, which may vary with each pest.
Pest Profile
Scientific Name: Bactrocera albistrigata (de Meijere)
Common Name: White striped
fruit fly
Threat Level: Medium
Characteristics: The adult white striped fruit fly resembles the Oriental fruit fly. The body has a dark stripe down the middle, flanked by two broader strips on the sides, with yellow coloring and a dark triangle mark on the thorax. The larvae are legless and may range in color from white to yellowish-white, and grow to a length of 0.4 or 2/5 inches within the host fruit.
Country of Origin: The white striped fruit fly is found in parts of Asia and Oceania, including India, Malaysia, Singapore, Thailand and Australia.
Possible Damage: Fruit that has been infested by the white striped fruit fly, with eggs laid in the fruit flesh and larvae tunneling through the fruit, is unfit for consumption. Preferred host plants are not common in California, but it is known to adapt and favor other plant hosts. The white striped fruit fly has the potential to become established and impact agricultural production areas of California.
Current Sightings: White striped fruit flies have been detected in Los Angeles County in peach, lemon, nectarine, ornamental plum, calomondin/kumquat and sapote plantings. Eradication activity is ongoing in the La Verne area of Los Angeles County.
Pest Profile
Scientific Name: Lobesia botrana
Common Name: European Grapevine Moth or Berry Moth
Threat Level: High
Characteristics: The adult European grapevine moth has creamy-white forewings with a pale-yellowish overlay, deeply bluish-gray coloring and black, yellow and light olive-brown markings spread across the wing. The larvae of the European grapevine moth have a yellowish brown head and an abdomen varying from yellowish green to whitish brown or brown, and can grow to approximately 9-10 mm long.
Country of Origin: The European grapevine moth is a significant agricultural pest in Europe, the Mediterranean, southern Russia, Japan, the Middle East, Near East and northern and western Africa.
Possible Damage: The European grapevine moth is a pest of concern because it can feed on the flower or fruit of host plants, most often grapes. If the moth attacks mature grape clusters, for example, the berries can become further damaged through infection of a fungus called botrytis, also known as bunch rot. This causes a decay of plant tissue and possible death.
Current Sightings: European Grapevine Moth was first detected in Oakville, California (near Napa) in September 2009 – the first detection in the United States. Quarantine has been set for portions of Napa, Sonoma and Solano Counties.
Pest Profile
Scientific Name: Epiphyas postvittana
Common Name: Light Brown Apple Moth (LBAM)
Threat Level: Medium
Characteristics: Small moth, approximately ¼ inch in length. Generally tan with some darker markings.
Country of Origin: Australia
Possible Damage: The LBAM caterpillar feeds on and damages the leaves and new growth of plants. On some plants, including grapes, apples, citrus and avocado, LBAM larvae also feed directly on the fruit, rendering it unmarketable. More than 250 kinds of plants are targeted by LBAM, including Monterey pine, cypress, oak, roses and many common crops and ornamental plants. Almost any plant in the average garden or yard is at risk.
Current Sightings: LBAM have been sighted and trapped in the following California counties: Alameda, Contra Costa, Los Angeles, Marin, Monterey, Napa, San Benito, San Diego, San Francisco, San Joaquin, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Solano, Sonoma and Yolo.
Pest Profile
Scientific Name: Ceratitis capitata Weidemann
Common Name: Mediterranean Fruit Fly (Medfly)
Threat Level: Medium
Characteristics: Smaller than a house fly, the Medfly has a blackish thorax marked with silver, a tan abdomen with darker stripes and clear wings with light brown bands and gray flecks.
Country of Origin: Originated in Africa but has spread throughout the Mediterranean region, southern Europe, the Middle East, Western Australia, South and Central America and Hawaii.
Possible Damage: The Medfly is among the most destructive, feared and well-publicized pests in the world. Medfly causes damage by infesting fruit, vegetables and nuts with eggs. As the larvae develop and feeds on the pulp, the fruit decays and falls to the ground, thereby destroying the crop. The Medfly has been recorded infesting more than 300 cultivated and wild fruits, vegetables and nuts.
Current Sightings: Medfly is being eradicated from the Escondido, Fallbrook and Imperial Beach areas of San Diego County and in Santa Monica in Los Angeles County.
Pest Profile
Scientific Name: Anastrepha ludens
Common Name: Mexican Fruit Fly
Threat Level: Medium
Characteristics: Larger than a house fly, the Mexican Fruit Fly’s body is a pale orange-yellow color with two to three whitish stripes along the thorax. The wings are clear with several yellow and brown stripes.
Country of Origin: Central Mexico
Possible Damage: Fruit that has been attacked by the Mexican fruit fly is unfit to eat. The larvae feed while tunneling through the interior of infested fruits. Microscopic organisms then invade these injured areas, causing internal decay of the fleshy portions of the fruit. People may unknowingly transport infested fruit because the infestation cannot always be found through visual inspection. More than 50 host plants have been recorded as “favorites” of this pest.
Current Sightings: No current eradication efforts are underway.
Pest Profile
Scientific Name: Thaumatotibia leucotreta (Meyrick)
Common Name: False Codling Moth (FCM)
Threat Level: Low
Characteristics: Adults are small, brownish-gray, nocturnal moths with an average wingspan of 3/5 inches.
Country of Origin: Native to Sub-Saharan Africa
Possible Damage: The False Codling Moth (FCM) feeds on more than 100 host plants and is a pest of fruit trees, field crops and other plants. California’s vast agricultural industry is at risk and environmental effects could result from increased pesticide use and feeding on native plants.
Current Sightings: FCM has been found in Ventura County.
Pest Profile
Scientific Name: Phytophthora ramorum or P. ramorum
Common Name: Sudden Oak Death (SOD)
Threat Level: High
Characteristics: P. ramorum is a water mold pathogen that causes Sudden Oak Death. It naturally thrives in cool, wet climates and can spread through wind-blown rain, contaminated irrigation water and infected plants.
Country of Origin: Discovered in the U.S. and in European nurseries in the mid-1990s.
Possible Damage: P. ramorum has a broad range of hosts, including hardwoods, softwoods, landscape plants and herbaceous plants. Infection results in the formation of as cankers and trees may survive several years. In the final disease stage, the leaves turn from green to brown within a few weeks and the cankers gradually expand until they girdle the tree, causing it to die.
Current Sightings: SOD was confirmed in and is currently regulated in 14 counties: Alameda, Contra Costa, Humboldt, Lake, Marin, Mendocino, Monterey, Napa, San Francisco, San Mateo, Santa Clara, Santa Cruz, Solano and Sonoma.
Pest Profile
Scientific Name: Bactrocera Dorsalis Hendel
Common Name: Oriental Fruit Fly
Threat Level: Medium
Characteristics: Somewhat larger than a house fly, the Oriental Fruit Fly’s body color is generally bright yellow with a dark "T" shaped marking on the abdomen. The wings are clear.
Country of Origin: Oriental fruit fly is a tropical species that is widespread through much of the mainland of Southern Asia and neighboring islands.
Possible Damage: The short life cycle of the Oriental fruit fly allows rapid development of serious outbreaks, which can cause severe economic losses. Heavy infestations can cause complete losses of crops. Oriental Fruit Flies have attacked more than 230 types of fruits and vegetables.
Current Sightings: Oriental fruit fly eradication activity is ongoing in the La Verne area of Los Angeles County and the Elk Grove area of Sacramento County.
Pest Profile
Scientific Name: Lymantria
dispar L
Common Name: Gypsy Moth
Threat Level: Low
Characteristics: Male moths are brown and approximately 1.5 inches in length; females are nearly white with dark saw-toothed patterns on their wings and two inches in length.
Country of Origin: Native to multiple European countries
Possible Damage: Gypsy moth caterpillars prefer approximately 150 primary hosts but feed on more than 500 species of trees and shrubs and are capable of defoliating trees at an alarming rate. A single gypsy moth caterpillar can eat up to one square foot of leaves per day. When trees are repeatedly defoliated, they become more susceptible to other pests and diseases, leading to tree death and an increased potential for fire and erosion. Defoliation also destroys habitat for mammals and birds.
Current Sightings: European Gypsy Moth has been found and eradicated in Ojai, in Ventura County.
Pest Profile
Scientific Name: Diaphorina citri (Kuwayama)
Common Name: Asian Citrus Psyllid (ACP)
Threat Level: High
Characteristics: Adults are aphid-like in appearance, measuring about 1/8 inch in size. The bodies are grayish-tan with brown markings and mottled brown wings. When approached, they jump or fly.
Country of Origin: Tropical and subtropical Asia
Possible Damage: The ACP threatens citrus plants and citrus relatives in two ways: it damages new plant growth as it feeds but, even worse, it is a host to the deadly citrus disease Huanglongbing (HLB), or citrus greening disease. HLB is a bacterial disease that greatly reduces production, destroys the economic value of fruit and eventually kills trees. Once infected, there is no cure for a tree with HLB; within a few years, infected trees decline and die.
Current Sightings: ACP has been detected in Imperial, Los Angeles, Orange, Riverside, San Bernardino and San Diego counties. No HLB disease has been found in California at this time.
