These insects are on the most-wanted list of many states. They’re a nuisance and they’re showing up in nurseries as hitchhikers on plants or equipment, or even dispersed by storms.
Scout regularly in-house or hire a professional to do the job frequently. Knowing what you’re up against is half the battle. In April, we’ll highlight control measures for these unwelcome crawlers and fliers.
Asian longhorn beetle
Scientific name:Anoplophora glabripennis.
Description: Adults measure 1 inch to 1 1/2 inches with long antennae. The body is shiny and black with white markings on both the body and the antennae.
Hosts: Hardwoods, including several maple species (
Symptoms: As the adult chews its way out of the tree, it leaves behind round, 3/8-inch holes with frass and sap.
Biology: Adult females lay eggs into bark depressions. Once the eggs hatch, small white larvae bore their way through the bark and feed on the vascular layer. The larvae feed deeper, forming tunnels in the trunk and branches. This damage weakens the integrity of the tree, and a severe infestation may kill it. Over the course of a year, a larva will mature and then pupate near the surface, under the bark. Adults typically emerge from June through October.
History: The Asian longhorn beetle was discovered in Brooklyn, N.Y., in 1996. It eventually spread to Manhattan, Queens and Long Island. It was discovered in Chicago in 1998, in Jersey City, N.J., in 2002 and Middlesex and Union counties in 2004. The pest likely arrived in the U.S. on wood packing material from Asia.
Chilli thrips
Scientific name: Scirtothrips dorsalis Hood.
Description: Field identification of S. dorsalis is extremely difficult. It’s often impossible to differentiate it from other thrips in the field. Adults have a pale body with dark wings and are less than 2 millimeters long. Immature S. dorsalis thrips are pale and resemble the immatures of other thrips species.
Hosts: There are more than 100 reported hosts, but some common landscape hosts include roses, ligustrum, lisianthus, pittosporum, herbs, begonia and Indian hawthorn. The pest also threatens cotton, peanuts, grapes, tomatoes and peppers.
Symptoms: The pest is mainly a forage feeder, preferring new leaves and buds. Feeding damage turns tender leaves, buds and fruits bronze. Damaged leaves curl upward and appear distorted. Infested plants become stunted or dwarfed, and leaves with petioles detach from the stem, causing defoliation in some plants. Feeding on buds may cause them to become brittle and drop.
Biology: Female S. dorsalis insert eggs inside plant tissue. The eggs hatch in six to eight days. Two larval stages, first and second instars, last for six to seven days, and this is when they actively feed. They do not feed during the prepupal and pupal stages. Its life cycle is complete in 14-20 days.
History: Chilli trips were first discovered on roses in Palm Beach County, Fla., in October 2005. To date, the pest has been discovered in Florida and Texas. It’s been recorded in
Emerald ash borer
Scientific name:Agrilus planipennis Fairmaire.
Description: Adults are roughly 3/8 to 5/8 inch long with metallic-green wing covers and a coppery-red or purple abdomen.
Hosts: Fraxinus spp.
Symptoms: Larvae feed in the phloem and outer sapwood, producing galleries that eventually girdle and kill branches and entire trees. Adult beetles leave distinctive D-shaped exit holes in the outer bark of the branches and trunk.
Biology: Females lay eggs in bark crevices from late May through July. Larvae tunnel in the cambial layer and move into the sapwood. Larvae feed aggressively until lower fall temperatures arrive, and then overwinter in the tree. Pupation is in late April to June. Adults emerge in mid-May, peaking in late June and may continue emerging as late as mid- and late-July.
History: EAB was first discovered in southeast
Gypsy moth
Scientific name:Lymantria dispar.
Description: Egg masses are beige and about the size of a quarter. Caterpillars are 1 to 2 inches long when fully grown, with hairlike structures along the entire length of their body. Grayish, with five pairs of blue spots and six pairs of red spots along their back, the caterpillars have yellow markings on their head. Male moths have a wingspread of 1 inch. They are light tan to dark brown and have blackish wavy bands across their forewings with arrowhead markings near the leading edge. Female moths are nearly white with faint, dark wavy bands on the forewings.
Hosts: More than 500 species of trees and shrubs.
Symptoms: Look for egg masses, caterpillars and defoliation.
Biology: Egg masses appear in July and August. Larvae emerge the following April or May and begin devouring leaves. The caterpillar stage lasts 10 to 12 weeks. Transformation from caterpillar to moth takes place during a 10- to 14-day period. From June to August, larvae enter the pupal, or resting, stage.
History: Originally introduced into Massachusetts in 1869, the gypsy moth has slowly spread north to Maine and south to North Carolina, infesting 19 states and the District of Columbia. Despite state and local control efforts, the infestation continues to move south and west.
Imported fire ants
Scientific name:Solenopsis invicta Buren, S. richteri Forel, and their hybrid.
Description: Identifying fire ants is difficult because they look like ordinary ants. They are 1/8 to 1/4 inch long and reddish-brown to black. Fire ants are probably best distinguished by their aggressive behavior and characteristic mound-shaped nests.
Hosts: Buds and fruit of plants, pets, wildlife and humans.
Symptoms: These insects feed on buds or fruits of many plants and may remove bands of bark from young citrus trees, often killing them. Their hard, cone-shaped mounds can be as high as 2 feet. They’re a major threat to livestock and humans because of their aggressive nature and painful stings.
Biology: A mature, 3-year-old colony typically contains 250,000 workers, which are sterile females, and hundreds of reproductive males and potentially reproductive females. A colony population can grow to 300,000 ants. In addition to single-queen colonies, many fire ant colonies have multiple queens, increasing tenfold the number of mounds in a single acre. Ants travel long distances by hitchhiking in vehicles and in or on soil, plants with roots and soil attached, nursery stock, sand, gravel, grass, sod, hay, wood or soil-moving equipment.
History: Two species of imported fire ants were introduced into the United States from South America at the port of Mobile, Ala. The black imported fire ant arrived around 1918 and the red imported fire ant in the late 1930s. To date, the IFA infests more than 320 million acres in Alabama, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, New Mexico, North Carolina, Oklahoma, South Carolina, Tennessee, Texas and Puerto Rico.
Light brown apple moth
Scientific name:Epiphyas postvittana.
Description: The adult moth is about 10 millimeters long when resting with wings folded in a characteristic bell shape. It’s generally yellowish-brown with darker-brown markings on the forewings. Females often have a dark spot on the hind margin of the forewing. Adult moths must be identified by a qualified entomologist. Caterpillars are tiny with a pale-yellow-green body and a pale-brown head. The pupa is green first, but soon becomes brown after rapidly hardening, and then darkens during development. The pupa is typically found in a thin-walled silken cocoon between two leaves webbed together.
Hosts: More than 1,000 plants, including cypress, redwood, oak and stone fruit.
Symptoms: The pest destroys, stunts or deforms young seedlings; spoils the appearance of ornamental plants; and injures deciduous fruit-tree crops, citrus and grapes.
Biology: Females can lay eggs six to 10 days after moth emergence, depending on the temperature. Eggs take from five to more than 30 days to hatch, depending on the temperature.
History: Although it was reported in
Pine shoot beetle
Scientific name:Tomicus piniperda L.
Description: Adult pine shoot beetles are 3 to 5 millimeters long, or about the size of a match head. They are brown or black and cylindrical. The legless larvae are about 5 millimeters long with a white body and brown head.
Hosts: Scotch pine (Pinus sylvestris) is the principle host, but other pine species are susceptible.
Symptoms: The beetle attacks new pine tree shoots, stunting the growth. It may also attack stressed pine trees by breeding under the bark at the base of the trees. Affected shoots droop, turn yellow, and eventually fall off in summer and fall.
Biology: Pine shoot beetles complete only one life cycle per year. They spend winter inside the thick bark at the base of living pine trees. The beetles become active and leave overwintering sites in March and April (when temperatures reach 54°F) to mate and lay eggs in dying or stressed pine trees, pine trees and stumps that have been recently cut, logs and bark mulch. From April to June, larvae feed and mature under the pine bark in separate feeding galleries. From July through October, adults tunnel out through the bark and fly to new or 1-year-old pine shoots to begin maturation feeding.
History: It was first discovered in the U.S. at a Christmas tree farm near Cleveland in July 1992. It has been detected in parts of 12 states -- Wisconsin, Illinois, Indiana, Maryland, Maine, Michigan, New Hampshire, New York, Pennsylvania, Ohio, Vermont and West Virginia.
Pink hibiscus mealybug
Scientific name:Maconellicoccus hirsutus.
Description: It’s reddish-brown or pink and absent of fringe and stripes on the back. It has very little wax on the body. Anal filaments are short and the ovisac is irregular and located beneath the body. When the mealybugs are crushed, body fluid is dark red. Eggs are bright pink to red.
Hosts: More than 300 species, including Allamanda, Angelica, Anthurium, Bougainvillea, Croton, ginger lily, Heliconia, Ixora, hibiscus, palm and oleander.
Symptoms: Feeding causes new leaves to curl, giving a “bunchy top” appearance. Like other mealybugs, pink hibiscus mealybugs (PHM) excrete honeydew, which turns leaves shiny at first and then black, as sooty mold grows.
Biology: Adult female PHM has five life stages: Egg, first instar, second instar, third instar and fourth instar. Adult male PHM has six life stages: Egg, first instar, second instar, third instar, fourth instar and fifth instar. Females secrete an irregular-shaped white cottonlike egg mass that contains 300 to 600 eggs that turn pink as they mature. First instars are pink and emerge from the eggs. In tropical climates, PHM remains active year-round and may produce up to 15 generations per year. In cooler climates, PHM overwinters in the egg or adult female stage in bark crevices, soil, tree holes, fruit and crumpled leaf clusters.
History: It was found in Southern California in 1999 and Florida in 2002 where a biological control program was immediately implemented with great success. In 2004, nursery stock infested with PHM was accidentally shipped to 36 states. These states are considered “climatically suitable” for the pest’s establishment:
Red palm mite
Scientific name:Raoiella indica Hirst.
Description: Red mites are usually found on the undersides of leaves and are often in groups of hundreds of individuals that are visible with the naked eye. Cast skins are white and are often more numerous than living mites.
Hosts: The pest primarily infests palms and bananas, but has been found on gingers and heliconias.
Symptoms: Feeding mites, especially at high densities, cause localized yellowing of leaves followed by tissue necrosis.
Biology: Red palm mite can reproduce without mating. Unfertilized eggs develop into males, while fertilized eggs develop into females. The eggs are deposited on lower-leaf surfaces, and they hatch in about seven days. The newly emerged mites are sexually active. The introduction of a single female, which lives about 27 days and mates multiple times during her life, could establish a new colony.
History: It was confirmed in Palm Beach County, Fla., in November 2007. The first Western Hemisphere report of the red palm mite was in 2004 from the eastern Caribbean
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- Kelli Rodda
March 2008
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