Insect Management on Landscape Plants
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Insect Management on Landscape Plants

   

Insect Management on Landscape Plants1

Eileen A. Buss2

The urban landscape is a diverse area that includes many different plants, ranging from annual foliage plants to perennial trees and shrubs. It is a complicated system to manage because, unlike in agriculture, plantings are fragmented and separated by developed areas. Each home or commercial area is also maintained differently, and the owners or managers have different goals for their landscapes. Some may desire a perfect, well-manicured look, while others may prefer a more natural appearance that requires less work to maintain.

A lot of insects, mites, and other insect-relatives feed on ornamental landscape plants. Many are harmless, some are beneficial, and some are pests. Some pests may need immediate control, especially if present in great numbers, but others may not be worth the time, effort, or cost of control. Feeding by pests may cause real damage to the plants or just make the plants look bad or unhealthy. However, insects are only one of many potential causes for unhealthy-looking plants. Diseases, nematodes, drought, nutritional disorders, and improper chemical applications can also be damaging. Correct identification of the problem can save money and prevent unnecessary chemical use. After the pest is correctly identified, information can be found on its life cycle, food preference, and habits. It is important to understand these things to properly time any corrective measures.

Scouting or monitoring for damage or pests is an important part of plant health care. Examine plants weekly in the spring, summer and fall. Exactly how to monitor for each pest depends on where the insect lives or feeds. Look for pests under a few leaves and the stems or branches of each plant. If thrips or mites are suspected, hold a sheet of white paper under the leaves or flowers and shake the plant. Watch for moving specks on the paper and place them into a small jar or vial of rubbing alcohol for identification. Use a hand lens (10 or 15X) or magnifying glass to find tiny insects or mites on the foliage.

Pest Management on Ornamentals

Several options exist for managing insects and mites on ornamentals without the use of pesticides. These options include handpicking, knocking, or hosing pests off plants with water, and then destroying the pests. Removing infested plants or plant parts (e.g., pruning) and then burning or destroying them reduces the chance of pests moving among plants. Buying or using plants that are naturally resistant or tolerant to certain pests greatly reduces the need for future control. Any mechanical or cultural method that prevents or excludes pests from the plants should be attempted before using a pesticide.

However, if pesticide use is necessary to prevent economic damage to plants, consult Tables 1 and 2 . Most of these pesticides kill by either contact with the insect or as a stomach poison. Some may also exert a fumigating or vapor action under certain conditions. Products should be selected that will effectively control the pests without injuring the plant, result in another pest outbreak, or kill beneficials and other non-target organisms. Before using a pesticide, consider the following points:

Groups of Pests

Pests of ornamentals may be divided into five groups according to how they damage plants.

  1. Insects with Piercing-Sucking Mouthparts. These insects have general straw-like mouthparts, which pierce the plant tissue and suck out the plant fluids. Examples: Scales, mealybugs, aphids, whiteflies, mealybugs, lace bugs, spittlebugs, thrips.

  2. Spider Mites. These pests are not insects, but are closely related to spiders and scorpions. They suck plant fluids with their piercing-sucking mouthparts.

  3. Foliage-Feeding Insects. They may feed on leaves or flowers. Examples: Caterpillars, beetles, grasshoppers, katydids.

  4. Leafminers. These are very small larvae of flies, beetles, or moths that tunnel between the upper and lower leaf surfaces. Examples: Blotch leafminers and serpentine leafminers.

  5. Borers. There are many species of insects which bore into the twigs or trunks of plants and trees. These are usually the larvae of moths or beetles. Examples: Pine bark beetles, sea grape borer, carpenterworm, dogwood borer.

For a list of key plants and their associated pests see List 1 .

Additional Information

For additional information, please see these extension publications (http://edis.ifas.ufl.edu ):

Beneficial Insects and Mites (ENY-276)

Insect Attractants and Traps (ENY-277)

Microbial Insecticides (ENY-275)

Natural Enemies and Biological Control (ENY-822)

Featured Creatures (http://creatures.ifas.ufl.edu)

Plant/Pest Guide

Part 1

Part 2

Part 3

Tables

Table 1. Insecticides registered for use in Florida landscapes.1

Insect


Chemical Name


Notes


Aphids


Abamectin

Acephate

Azadirachtin

Bifenthrin

Carbaryl

Clothianidin

Cyfluthrin

Horticultural oil

Imidacloprid

Insecticidal soap

Malathion

Permethrin

Pymetrozine


Treat when aphids first appear and retreat when needed.

Do not use Malathion on ferns or Chinese elms.


Bagworm


Acephate

Azadirachtin

Bacillus thuringiensis k.

Bifenthrin

Carbaryl

Cyfluthrin

Lambda-cyhalothrin

Permethrin

Spinosad


Treat when bagworms are small.

Remove and destroy bags from plants in winter.


Beetles (Leaf-feeding)


Acephate

Azadirachtin

Bifenthrin

Carbaryl

Cyfluthrin

Deltamethrin

Imidacloprid

Permethrin

Spinosad



Borers


Bifenthrin

Carbaryl

Imidacloprid

Permethrin


Apply insecticide to plants before adults oviposit, eggs hatch, or larvae tunnel inside.
Caterpillars (e.g. oleander caterpillar , white marked tussock moth larva )


Acephate

Bacillus thuringiensis k.

Bifenthrin

Carbaryl

Cyfluthrin

Deltamethrin

Lambda-cyhalothrin

Permethrin

Spinosad


Treat when larvae are small.
Centipedes , Millipedes , Sowbugs , Pillbugs


Bifenthrin

Carbaryl

Clothianidin

Cyfluthrin

Deltamethrin

Lambda-cyhalothrin

Permethrin



Gall Insects


Abamectin

Carbaryl

Spinosad


Many gall-makers are present near bud break. Treat when insects are laying eggs or early in gall development.
Grasshoppers


Acephate

Bifenthrin

Carbaryl

Cyfluthrin

Deltamethrin

Lambda-cyhalothrin


Treat when first noticed on plants. Retreat as necessary.
Lace bugs


Acephate

Bifenthrin

Carbaryl

Cyfluthrin

Deltamethrin

Horticultural oil

Imidacloprid

Insecticidal soap

Lambda-cyhalothrin

Malathion

Permethrin


Treat when lace bug numphs are first seen. Repeat as needed to protect foliage.
Leafhoppers


Acephate

Azadirachtin

Bifenthrin

Carbaryl

Clothianidin

Cyfluthrin

Deltamethrin

Horticultural oil

Imidacloprid

Insecticidal soap

Lambda-cyhalothrin

Permethrin


Treat when leafhoppers are seen and repeat as needed.
Leafminers


Abamectin

Acephate

Azadirachtin

Bifenthrin

Carbaryl

Clothianidin

Imidacloprid

Permethrin

Spinosad


Standard contact insecticides may be used against adult leafminers at oviposition. Some systemic insecticides may be active against larvae in mines.
Leafrollers


Acephate

Azadirachtin

Bacillus thuringiensis k.

Bifenthrin

Carbaryl

Lambda-cyhalothrin

Permethrin

Spinosad


Often not damaging enough to warrant control in the landscape. Time applications before leaf rolls are complete and insects are protected inside the plant material.
Mealybugs


Acephate

Azadirachtin

Bifenthrin

Clothianidin

Cyfluthrin

Deltamethrin

Imidacloprid

Insecticidal soap

Lambda-cyhalothrin

Permenthrin


If mealybugs have formed ovisacs (cottony masses in which egs are laid), additional applications may be needed at 7-10 day intervals until no new mealybugs are found.
Mites


Abamectin

Azadiractin

Bifenthrin

Bifenazate

Cyfluthrin

Dicofol

Fenpropathrin

Horticultural oil

Insecticidal soap

Lambda-cyhalothrin

Malathion

Neem oil

Pyridaben

Spiromesifen


Correct identification of spider mite species is essential in determining control timing. A spray probram is usually necessary. Apply miticide 2 or 3 times, at 7-10 day intervals.

Do not use abamectin on conifers.


Scales (Crawlers)


Acetamiprid

Azadirachtin

Carbaryl

Cyfluthrin

Dinotefuran

Horticultural oil

Imidacloprid

Insecticidal soap

Malathion


Crawlers (nymphs) are most susceptible to applications, but timing of emergence varies by scale species. Some crawlers settle on plant foliage and others settle on branches and twigs. Armored scales are generally not susceptible to dormant oil sprays.


Slugs and Snails


Methiocarb

Metaldehyde


Apply when leaf damage is first seen and reapply as needed.
Spittlebugs


Acephate

Carbaryl

Cyfluthrin

Deltamethrin

Lambda-cyhalothrin


Treat when spittle masses first appear.
Thrips


Abamectin

Acephate

Bifenthrin

Carbaryl

Cyfluthrin

Fluvalinate

Imidacloprid

Malathion

Methiocarb

Spinosad


Treat foliage or flowers as soon as thrips are found. Weekly applications may be needed until control is achieved.


Whiteflies


Abamectin

Azadirachtin

Bifenthrin

Carbaryl

Clothianidin

Horticultural oil

Imidacloprid

Insecticidal soap

Lambda-cyhalothrin

Malathion

Pymetrozine

Spiromesifen


Treat when first noticed and repeat in 5-10 days. Repeat applications as needed.


1 The pesticides included in this table have been listed alphabetically, and not based on their effectiveness of control. We do not have information on the effectiveness of each pesticide.


Table 2. Chemical names, trade names, formulations, and manufacturers of landscape pesticides.

Chemical Name


Florida Registered Products


Chemical Class


Signal Word


Abamectin


Avid 0.15 EC


Avermectin
Warning


Acephate1


Acephate Pro 75

Orthene Turf, Tree & Ornamental Spray


Organophosphate
Caution

Caution


Acetamiprid


TriStar 70 WSP


Neonicotinoid


Caution


Azadirachtin


Azatin XL


Botanical
Caution
Bacillus thuringiensis var. kurstaki1


Dipel DF

Safer Caterpillar Killer

XenTari


Microbial
Caution

Caution

Caution


Bifenazate
Floramite


Miticide/Pyridinecarboxylic acid


Caution
Bifenthrin1


Talstar Lawn & Tree Flowable

Onyx Insecticide


Pyrethroid
Caution

Warning


Carbaryl1


Carbaryl 4L

Sevin SL

Sevin 80 WSP


Carbamate


Caution

Caution

Warning


Clothianidin


Arena 50 WDG


Neonicotinoid


Caution


Cyfluthrin1


Tempo 20 WP

Tempo SC Ultra


Pyrethroid


Caution

Caution


Deltamethrin
DeltaGard T&O


Pyrethroid
Caution
Dicofol
Kelthane 35
Miticide
Warning
Dinotefuran


Safari 20 SG


Neonicotinoid


Caution


Fenpropathrin


Tame 2.4 EC*


Miticide
Warning
Fluvalinate
Mavrik Aquaflow


Pyrethroid
Caution
Horticultural oil1


Sunspray Ultra Fine

Ultra-Fine Oil


--
Caution

Caution


Imidacloprid1


Merit 75 WP / WSP


Neonicotinoid


Caution
Insecticidal soap1


M-Pede

Safer's Soap


--
Warning

Caution


Lambda-cyhalothrin
Scimitar CS


Pyrethroid
Caution
Malathion
Malathion 5 EC


Organophosphate


Warning
Metaldehyde
Deadline Bullets

Metaldehyde Granules 3.5


Molluscicide


Caution

Caution


Methiocarb
Mesurol 75W *


Carbamate
Warning
Neem oil1


Triact 70
Botanical
Caution
Permethrin1


Astro

Permethrin Pro Termite-Turf-Ornamental


Pyrethroid
Caution

Caution


Pymetrozine
Endeavor


Feeding blocker


Caution
Pyridaben
Sanmite 75 WP
Miticide


Warning
Spinosad1


Conserve SC


Miticide


Caution
Spiromesifen


Forbid 4F


Ketoenoles


Caution


* Restriced Use Pesticide

1 Some products exist for homeowner use



Footnotes

1. This document is ENY-338 (IG013), one of a series of the Department of Entomology and Nematology, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Date frist printed: October 1993. Revised: September 2007. Please visit the EDIS Website at http://edis.ifas.ufl.edu.

2. Eileen A. Buss, associate professor, Entomology and Nematology Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, 32611.


The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition. All chemicals should be used in accordance with directions on the manufacturer's label. Use pesticides safely. Read and follow directions on the manufacturer's label.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.



Copyright Information

This document is copyrighted by the University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS) for the people of the State of Florida. UF/IFAS retains all rights under all conventions, but permits free reproduction by all agents and offices of the Cooperative Extension Service and the people of the State of Florida. Permission is granted to others to use these materials in part or in full for educational purposes, provided that full credit is given to the UF/IFAS, citing the publication, its source, and date of publication.