Azalea Lace Bug.pdf

Agricultural Extension Service

The University of Tennessee

Insects

SP 290-E

Azalea Lace Bug

Frank A. Hale, Associate Professor

Originally developed by Harry E. Williams, Professor Emeritus

Entomology and Plant Pathology

Since its introduction from Japan in the early 1900’s,

the azalea lace bug has become a destructive pest of azaleas.

Although this bug prefers evergreen azalea varieties, it will

infest deciduous varieties. Mountain laurel can also become

infested.

The smooth, white egg of the lace bug, which measures

approximately 0.4 mm by 0.8 mm, is flask shaped with the

neck to one side. It is usually deposited in the underside

tissue of a young leaf along the mid-rib or large vein. Each

egg is inserted in the tissue with its neck slightly about the

leaf surface.

Female lace bugs lay groups of eggs on the underside of

the leaves in September and October. These eggs overwinter

and hatch during March and April. The populations build

from spring through autumn with about four generations

possible. A large population of lace bugs can be established

during July, August and September. It is quite possible to

find all stages of the lace bug together under a leaf during

this time.

The adult lace bug is 1/8 inch long and 1/16 inch wide.

It has lacy wings with brown and black markings and light

brown legs and antennae. The young nymph lace bug is

nearly colorless at hatching but soon turns black and spiny.

It sheds its outer skin six times and ranges in size from 0.4

mm to 1.8 mm before becoming an adult.

Injury to the plants is caused by nymphs and adults as

they extract sap from the under surfaces of the leaves. The

damage appears as spotted discoloration or bleaching of the

upper surfaces of the leaves. In severe infestations, the

leaves become almost white, many of them drying com-

pletely and dropping off. The undersides of the leaves are

also disfigured by the black, dry, shiny excrement and cast

skins of the insects.

Adult azalea lace bug

Control Measures

Repeated applications of an insecticide are usually

needed to effectively control lace bugs. The first application

should be made as soon as nymphs appear in the spring,

followed by a second application seven to 10 days later.

Applications should be repeated at monthly intervals as

needed.

Thorough coverage of the undersides of the leaves

where the insects are found is essential if good control is to

be expected. Select one of the insecticides listed below and

follow the label directions. Chlorpyrifos is for use in

commercial nurseries, not for residential use.

• acephate (Orthane Turf, Tree & Ornamental Spray [75% SP], Address T/O [75% SP] );

•chlorpyrifos (Dursban 50 W [50% WSP]);

•beta-cyfluthrin (Tempo SC Ultra [1 lb/gal SC]);

•cyfluthrin (Advanced Garden Lawn & Garden Multi-Insect Killer [0.75% EC], Decathlon 20 WP [20% WP],

Tempo 20 WP [20% WP]);

•midacloprid (Merit 75 WP [75% WP], Merit 2 [2 lb./gal.F], Merit 2.5 G [2.5%G], Marathon 60 WP [60% WP],

Marathon II [2 lb./gal.F], Advanced Garden Tree and Shrub Insect Control[1.47% concentrate]);

•cyfluthrin plus imidacloprid (Advanced Garden Rose & Flower Insect Killer [0.72% cyfluthrin, 0.72% imidacloprid]);

•disulfoton plus 16-8-8 fertilizer (Advanced Garden 2-in-1 Systemic Azalea, Camellia & Rhododendron Care [1% G]);

•dimethoate (Dygon 400 [4 lb/gal EC], Dimethoate 2.67 EC [2.67 lb/gal EC]); OR

• horticultural oil (SunSpray Ultra-Fine Spray Oil [98% EC], Ultra-Fine Oil [98% EC]).

Marathon 60WP is for use only on greenhouse and

nursery ornamental plants, using soil drenches or through an

irrigation system. On stock plants and woody crops with a

production cycle of greater than one year, application may

not exceed once a year.

Merit 75 WP and Merit 2 can be used on turfgrass,

landscape ornamentals and interior plantscapes. It can be

applied to the foliage or even more effectively as a soil

injection or soil drench. When using a soil injection or soil

drench, make application 30 days prior to anticipated pest

infestation. The addition of a nitrogen containing fertilizer,

where applicable, into the solution will enhance the uptake

of the active ingredient.

In order to protect people and the environment, pesticides should be used safely. This is everyone’s responsibility, especially the user. Read and follow

label directions carefully before you buy, mix, apply, store or dispose of a pesticide. According to laws regulating pesticides, they must be used only as

directed by the label. Persons who do not obey the law will be subject to penalties.

Disclaimer Statement

Pesticides recommended in this publication were registered for the prescribed uses when printed. Pesticides registrations are continuously reviewed.

Should registration of a recommended pesticide be canceled, it would no longer be recommended by The University of Tennessee.

Use of trade or brand names in this publication is for clarity and information; it does not imply approval of the product to the exclusion of others which

may be of similar, suitable composition, nor does it guarantee or warrant the standard of the product.

Visit the Agricultural Extension Service Web site at

http://www.utextension.utk.edu/

SP290-E 1M 6/03(Rev) E12-4615-00-033-03

The Agricultural Extension Service offers its programs to all eligible persons regardless of race, color, age,

national origin, sex, veteran status, religion or disability and is an Equal Opportunity Employer.

COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS

The University of Tennessee Institute of Agriculture, U.S. Department of Agriculture,

and county governments cooperating in furtherance of Acts of May 8 and June 30, 1914.

Agricultural Extension Service

Charles L. Norman, Dean

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika: