<b>Trees, Ornamental & Bedding Plant:</b> Pest ID is the first step to management

These insects are on the most wanted list of many states. They’re a nuisance and they’re showing up in landscapes as hitchhikers on plants or equipment, or even dispersed by storms.
 

1. Asian longhorn beetle
Photo: USDA
Scientific name: Anoplophora glabripennis.
Description: Adults are 1 inch to 1 1/2 inches long with long antennae. The body is shiny and black; white markings appear on both the body and antennae.
Hosts: Hardwoods, including some maple species (Norway, sugar, silver and red maple), box elder, horsechestnut, buckeye, elm, London plane, birch and willow.
Symptoms: As the adult chews its way out of the tree, it leaves behind round 3/8-inch holes with frass and sap.

2. Chilli thrips
Photo: Lance Osborne
Scientific name: Scirtothrips dorsalis Hood.
Description: Field identification of S. dorsalis is difficult and often impossible to differentiate from other thrips in the field. Adults have a pale body with dark wings and are less than 2 mm long.
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 hot 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. Buds may become brittle and drop.

3. Emerald ash borer
Photo: APHIS
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 sp.
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.

4. Gypsy moth
Photo: APHIS
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 bodies. 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 about 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. Egg masses appear in July and August. Larvae emerge the following April orMay and begin devouring leaves. The caterpillar stage lasts 10 to 12 weeks. Transformation from caterpillar to moth takes place during a 10- to14-day period. From June to August, larvae enter the pupal, or resting stage.

5. Imported fire ants
Photo: USDA
Scientific name: Solenopsis invicta Buren, S. richteri Forel, and their hybrid.
Description: Fire ants look much 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 nursery and agriculture stock, 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 get as high as 2 feet. They’re a major threat to livestock and humans because of their aggressive nature and painful stings.

6. Light brown apple moth
Photo: CDFA
Scientific name: Epiphyas postvittana.
Description: The adult moth is about 10 mm long when resting with the wings folded in a characteristic bell shape. It’s generally yellowish-brown with darker brown markings on the forewings. The 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 at first green, 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 a thousand 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..

7. Pine shoot beetle
Photo: USDA
Scientific name: Tomicus piniperda L.
Description: Adult pine shoot beetles are 3 to 5 mm long, or about the size of a match head. They are brown or black and cylindrical. The legless larvae are about 5 mm 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 during the summer and fall.

8. Pink hibiscus mealybug
Photo: Jeffery Lotz FDACS
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 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, the pink hibiscus mealybug (PHM) excrete honeydew, which turns leaves shiny at first and then black, as sooty mold grows on the accumulated honeydew.

9. Red palm mite
Photo: ARS
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 infesting gingers, heliconias and other ornamentals.
Symptoms: Feeding mites, especially at high mite densities, cause localized yellowing of the leaves followed by tissue necrosis.

The author is editor of Nursery Management & Production.