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Alameda County, CA, acgov.org

Humberto Izquierdo
County Agricultural Commissioner / Sealer
Agriculture / Weights & Measures

Plant and Pest Gallery


Exotic Pests gallery EXOTIC PESTS


Exotic Pests are pests that are not native to the area and present a serious threat to the agricultural economy. Exotic Pests are usually "A"-rated pests, sometimes "B"-rated.


NAME: Apple Maggot Fly
SCIENTIFIC NAME: Rhagoletis pomonella (Walsh)
PEST RATING: "B"
Adult fly is 1/4 inch (5-7 mm.) long, shiny black with white lines on sides of thorax and a white triangular scutellum at base of thorax. Females have four white cross bands on the abdomen, males have three. Wings have a black F-shaped marking. A serious pest of apples, also known to infest plum, peach, crabapple, sour cherry and ornamental hawthorn. This pest is present in some areas of Alameda County.

NAME: Asian Gypsy Moth - Adult Female
SCIENTIFIC NAME: Lymantria dispar Asian Strain L.
PEST RATING: "A"
This moth closely resembles the female European Gypsy Moth but is larger. Females have a wing span of 3 inches or more. Asian Gypsy Moth differs from the European stain by its ability to fly up to two miles and the fact that the larva will feed on conifers.

NAME: Asian Gypsy Moth - Adult Male
SCIENTIFIC NAME: Lymantria dispar Asian Strain L.
PEST RATING: "A"
This moth closely resembles the male European Gypsy Moth. Male moths have a 1 inch wing span. Asian Gypsy Moth life stages have been discovered hitch hiking on containers brought in by ships to the port of Oakland. The area is closely monitored with increased trapping activities.

NAME: Boll Weevil
SCIENTIFIC NAME: Anthonomus grandis grandis Boheman
PEST RATING: "A"
The Boll Weevil is a hard-shelled, grayish to brown, long legged beetle, about inch long. It has a slender snout, and two spurs on the inside of each front leg. Larva is white crescent shaped grub found inside cotton squares.

NAME: Caribbean Fruit Fly
SCIENTIFIC NAME: Anastrepha suspensa (Loew)
PEST RATING: "A"
Adults are 8 mm. in length. The body is light brown to honey colored. Wings have a complex pattern of light and dark brown markings. Females have a large ovipositor. This fly closely resembles the Mexican Fruit Fly.

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NAME: Colorado Potato Beetle
SCIENTIFIC NAME: Leptinotarsa decemlineata (Say)
PEST RATING: "A"
Adults measure about 3/8 inch long and have distinct pale yellow and black stripes on the forewing covers. Females deposit bright orange oval eggs on the under surface of leaves, where they are protected from direct sunlight. A serious pest of potatoes and other solanaceous plants.

NAME: European Corn Borer - Male and Female
SCIENTIFIC NAME: Ostrinia nubilalis (Hubner)
PEST RATING: "A"
Adult moths are approximately .8 - 1.4 inches long. ECB significantly affects the production of field corn, popcorn, seed corn, sweet corn, as well as other crops including sorghum, cotton, and many vegetables. Overall yield losses and control expenditures associated with the ECB cost farmers in the U.S. more than 1 billion dollars annually. ECB is present in all but the seven westernmost states.

NAME: European Pine Shoot Moth
SCIENTIFIC NAME: Rhyacionia buoliana (Denis & Schiffermuller)
PEST RATING: "A"
Adult moth is buff colored, about 1/2 inch long with a wingspan of 18 - 24 mm. The forewings are orange to rust in color and marked with silvery patterns. A serious pest of pines. Damage occurs during larval stage. Young larvae bore into the base of the needles after building a protective silken tube. In mid-summer the larvae tunnel through and bore into the buds. Learn more...

NAME: Glassy-winged Sharpshooter (GWSS)
SCIENTIFIC NAME: Homalodisca coagulata (Say)
PEST RATING: "B"
One of the largest leaf hoppers found in California. The adults are approximately inch (12mm.). The body is brown to black in color with white markings on the underside of the body. Wings are transparent with reddish veins. The head is brown to black with a distinguished "stippled" pattern of white to yellow spots. GWSS presents a serious threat to the grape and nursery industry.

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NAME: Guava Fruit Fly
SCIENTIFIC NAME: Bactrocera correcta (Bezzi)
PEST RATING: "A"
Similar to Oriental Fruit Fly, but smaller, measuring about 6mm. in length, with a darker, mostly black thorax. Body and legs are honey colored with a prominent black "T" marking on the abdomen. Wings are clear with a spot on the wing tips. Often confused with Peach Fruit Fly and Olive Fruit Fly. Learn more...

NAME: Gypsy Moth
SCIENTIFIC NAME: Lymantria dispar L.
PEST RATING: "A"
The female moth is a large white moth with black wavy lines across its 2 inch wingspan. Male moths are smaller, having a 1 inch wingspan. Males are brown with dark wavy lines across the wings. The female European Gypsy Moth does not fly. Note the close resemblance to the Asian Gypsy Moth.

NAME: Japanese Beetle
SCIENTIFIC NAME: Popillia japonica Newman
PEST RATING: "A"
Adult Japanese Beetles are oval shaped, inch long and inch wide. Their body is shiny metallic green with gold wing coverings. Along the bottom sides of the body are 6 noticeably white tufts of hair. Having a large host range makes this pest a serious threat to agriculture.

NAME: Khapra Beetle
SCIENTIFIC NAME: Trogoderma granarium
PEST RATING: "A"
Adult beetles are oval shaped, dark brown, and have smudgy yellowish-brown and reddish-brown transverse stripes on the wing covers. They are covered with fine hairs. Males are about 2 mm. long and females up to 3 mm. long. Larva is yellowish brown, spindle shaped and grow to 5 mm. long. Larva has thick reddish brown hairs and characteristic bunches of tail hairs growing off the rear. Learn more...

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NAME: Mediterranean Fruit Fly
SCIENTIFIC NAME: Ceratitis capitata Weidemann
PEST RATING: "A"
Adult flies measure 3.5-5.0 mm. long. Male Medflies have clubbed antennae that can be viewed under magnification. The most wide spread and serious pest of all the fruit flies. Medflies attack just about any host that has fleshy fruit tissue. Learn more...

NAME: Melon Fruit Fly
SCIENTIFIC NAME: Bactrocera cucurbitae (Coquillett)
PEST RATING: "A"
Adult fly is 8 mm. long, light brown to honey colored, with several bright yellow markings on the body. A very serious pest of cucurbit (melon, cucumber and squash) crops. The Melon Fruit Fly is known to attach over 125 different plants, some in plant families other than cucurbitaceae. Attacks flowers and fruits and sometimes stem and root tissue. Learn more...

NAME:Mexican Fruit Fly - Sterile Female
SCIENTIFIC NAME: Anastrepha ludens (Loew)
PEST RATING: "A"
Female flies are easily identified by their large ovipositor. Sterile Release fruit flies are marked with a fluorescent pink or orange dye that can be readily identified under ultraviolet lights. At times the dye can be detected under a microscope. Note the pink glow in the head capsule. All flies are sent to the State of Calif. Plant Pests Diagnostic Center for positive identification.

NAME: Olive Fruit Fly
SCIENTIFIC NAME: Bactrocera oleae
PEST RATING: "A"
The adult fly is 4-5 mm. long. The body is honey colored and has a white triangular shaped structure (scutellum) located at the base of the thorax. Wings are transparent with a small spot on the wing tips. The dark markings on the thorax and abdomen come in many variations. This fly can be easily confused with Peach Fruit Fly and Guava Fruit Fly.

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NAME: Oriental Fruit Fly
SCIENTIFIC NAME: Bactrocera dorsalis (Hendel)
PEST RATING: "A"
Adults are about 8 mm. in length. Body color is generally light brown to yellow with a distinct dark "T" pattern on the abdomen. There are several bright yellow lines and patches on the thorax. Wings are clear with a dark coastal vein.

NAME: Peach Fruit Fly
SCIENTIFIC NAME: Bactrocera Zonata (Saunders)
PEST RATING: "A"
The adult fly is 5-6 mm. long, orange to light brown, with yellowish abdominal cross bands. The wings are transparent with a small spot on the wing tips. There is a partial dark "T" pattern on the abdomen. Peach Fruit Fly is a serious pest and a strong flier capable of dispersing more than 25 miles in search of host plants. Two Peach Fruit flies were trapped in Alameda County in 1997 and quickly annihilated.

NAME: Red Imported Fire Ant
SCIENTIFIC NAME: Solenopsis Invicta
PEST RATING: "A"
Fire Ants are very small, reddish brown in color and range from 1/16 inch to 1/4 inch long. They are different from most ants commonly found in California but are not easily distinguished from other ants by simply looking at them. This ant is dangerous because it delivers venom which can be lethal to pets and sensitive people. Red Imported Fire Ants are a serious threat to humans, pets, wildlife, and agriculture.

NAME: Sweet Potato Weevil (SPW)
SCIENTIFIC NAME: Cylas formicarius elegantulus (Summers)
PEST RATING: "A"
Adults have a striking appearance in form and in color. They are red and metallic bluish-black with a long snout projected forward. The adults measure 5.5-8.0 mm. long. They may have as many as eight generations per year. SPW are a serious pest of sweet potatoes, not only in the U.S., but around the world.

NAME: Western Cherry Fruit Fly
SCIENTIFIC NAME: Rhagoletis indifferens
PEST RATING: "A"
Males are slightly larger than females, averaging 4.5 mm. long. The adult is blackish in color with a white triangular structure (scutellum) at the base of the thorax. The abdomen is marked with four white cross bands. Wings are marked with distinct black bands. Commonly confused with Apple Maggot Fly and Medfly.

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