Pest Management in Your Landscape

Grantham Garden Club 2019Rachel Maccini

PSEP Coordinator, Urban IPM Coordinator

IN THIS SESSION YOU WILL LEARN…

Know the main groups of pests

Learn about resources to identify specific pests and damage symptoms

Understand Integrated Pest Management (IPM)

What is a Pest?

Any organism that is detrimental to humans

Destroys crops and structures

Poses threats to human health and livestock

Reduces aesthetic and recreational value

Pests include insects, mites, plant pathogens, weeds, mollusks, fish, birds, and mammals

History Lesson: Pest Control

Primitive: pulling weeds, clubbing rats, plucking insects from foliage

Sulfur burning for mites/insects: 2500 B.C.

Lead arsenate in orchards – 1892

Lime and copper sulfate – Bordeaux mixture

Early pesticides – plant extracts or inorganics

WWII: DDT and low cost synthetic chemistry

Concerns with Pesticide Dependence

Pest resistance

Environmental persistence

Bioaccumulation: when a chemical accumulates in animal fat (historical fact)

Biomagnification: when an organism accumulates residues at higher concentrations than the organisms they consume

Pest Management

Is the pest really causing the problem?

1st step: Always identify the pest before taking any action!

Become familiar with its life cycle and habits

Misidentification results in lack of knowledge = ineffective control of the real pest

Four Major Pest Categories

#1 - Weeds: undesirable plants

Four Major Pest Categories

• #2 - Invertebrates, such as:

– Insects

– Spiders and mites

– Sowbugs, pillbugs

– Snails, slugs, and mussels

Four Major Pest Categories

• #3 – Vertebrates, such as:

– Birds

– Snakes

– Fish

– Rodents and other mammals

Four Major Pest Categories

• #4 - Plant Diseases

• Pathogens – living agents– Fungi

– Bacteria

– Viruses

– Nematodes

– Phytoplasmas

• Non-living agents: cold, heat, pollutants, dog urine

C.R. Foss

R.S. Byther

Pest Identification is Critical

• Understand that all stages of a pest do not look the same

• Know the host of the pest

• Use books, extension bulletins, field guides, Web, etc.

• Have pests examined by specialists

– Handle samples carefully

Vegetable Garden

Lawn

Flower Garden

Trees and Shrubs

Vegetable Garden

• Colorado potato beetle

• Cutworm

• Squash bugs

• Striped cucumber beetle

• Tomato / tobacco hornworm

Colorado potato beetle

• eggs are laid undersides of the leaves

• Both larvae and adults feed on leaves and fruit. After four instars, larvae pupate in the soil.

Damage

• Defoliation

• Feed on leaves, fruit and terminals

Management

• Cultural control – crush eggs, larvae and adults

• Use floating row covers

• Straw and thick mulch inhibits movement and encourages predator insects

• Natural predators – Stink bugs and lady beetles will prey upon Colorado potato beetle eggs and larvae and the fungus Beauveriabassiana will kill both larvae and adults.

Cutworms

• eggs are laid under debris in the soil

• Larvae are the cutworm, curl up into a tight “C” when disturbed

Damage

• Cut into young stems

• Feed on leaves- leaving a ragged leaf appearance

Management

• Cultural control – field plowing and clean cultivation

• Natural predators –parasitic wasps and tachinid flies

Tachinid fly eggs on a cutworm. Larvae will burrow in to feedPhoto courtesy U. Nebraska Entomology Dept.

Squash bugs

• Eggs are laid on cucurbit vines as they lengthen

• Nymphs pale green with black legs

Damage

• Small white dots or stipples, and leaves will appear tattered

Management

• Floating row covers will prevent egg laying

• Cultural control – remove egg clusters

• Natural predators –beetles and damsel bugs

• Chemical control – neem, horticultural oils sprayed on nymphs

Predators attacking squash bugs include (A) ground beetles and (B) damsel bugs. Photo credits: (A) Bill Snyder, Washington State University; (B) Ken Yeargan, University of Kentucky.

Striped cucumber beetles

• Eggs are laid on or just under coarse, cracked soil

• Larvae feed on roots and stems of plants

• Adults gouge and rasp fruits, transfer disease

Damage

• Plants wilt

• Holes in leavers, flowers and fruit

Management

• Remove garden debris in fall

• Lightly till soil to kill eggs and larvae

• Floating row covers over susceptible plants until flowering

• Plant timing June 15th for susceptible crops

Predators that feed on cucumber beetles include (a) wolf spiders and (b) ground beetles. Photo credit:

(a) Whitney Cranshaw, Colorado State University, Bugwood.org (b) John Goulet, Canadian Biodiversity

Information Center.

Tomato / Tobacco hornworm

• Lay eggs on lower and upper leaf surfaces

• Caterpillars feed 3-4 weeks

Damage

• Defoliator

Management

• Check plants 2 times per week

• Keep weeds at a minimum

• Till the soil after harvest

• Handpick hornworms

• Natural enemies - lady beetles and green lacewings often prey upon the egg stage and on young caterpillars, small braconid wasp, Cotesia congregatus

Flower Garden

• Aphids

• Japanese beetle

• Leaf miners

• Lily leaf beetle

• Plant bugs and leafhoppers

Aphids• Cluster on plants and are wingless

(most)

• Honeydew- shiny sticky substance

Damage

• Causes poor growth, stunted plants, curled and distorted leaves

Management

• Cultural controls – Spraying plants with forceful streams of water often washes off and kills aphids

• Keep weeds at a minimum

• Avoid high nitrogen fertilizers

• Natural enemies - various species of parasitic wasps that lay their eggs inside aphids. The skin of the parasitized aphid turns crusty and golden brown. Many predators also feed on aphids- lady beetle adults and larvae, lacewing larvae, soldier beetles, and syrphid fly

Japanese beetle

• Eggs are laid in the soil

• Larvae feed on roots in the ground

Damage

• Causes poor growth, stunted plants, feed on flowers and defoliate plants

Management

• Cultural controls adults – physical removal handpicking adults

• Cultural controls for grubs –withholding irrigation during peak adult beetle flight

• Biological control – few products that allegedly control grubs milky spore, insect parasitic nematodes and fungal pathogens

• curative” control- apply short residual products right after eggs have hatched (early to mid-august)

Leaf miners

• Eggs are laid in leaf tissue

• Larvae feed between the leaf layers

Damage

• Blotch or serpentine mines or trails

• Leaf discoloration

Management

• Cultural controls – monitor for adults using yellow sticky traps

• Control weeds which can act as secondary hosts

• Pick off or prune out affected leaves

• Biological Control – parasitoid wasps

Lily leaf beetle

• Eggs are laid on the undersides of new growth

• Larvae feed on true lilies, hollyhocks, and various hostaspecies

Damage

• Causes poor growth, stunted plants, feed on flowers and defoliate plants

Management

• Cultural controls adults –handpicking adults

• Chemical controls– Neem (small larvae)

• Biological control – larval parasitoids (Tetrastichus setifer)

Plant bugs and leaf hoppers

• Eggs are laid in woody tissue

• Nymphs feed for several weeks and are the cause of the damage

Damage

• Inject a plant toxin while feeding, distorts, deforms or destroys flower buds and leaves

Management

• Remove weeds from adjacent areas

• Contact insecticides may be used but control can be difficult because leafhoppers are very mobile (insecticidal soap)

• Natural enemies - lady beetles, lacewings, damsel bugs, and spiders.

Ornamental Trees and Shrubs

• Eastern tent caterpillar

• Fall webworm

• Viburnum leaf beetle

Eastern tent caterpillar

• Eggs are laid on twigs

• Caterpillars feed on foliage and form nests in branch crotches

Damage

• Defoliation, unsightly nests

Management

• Remove egg masses, or prune out webs

• Contact insecticides may be used but the tents need to be broken open

• Natural enemies - parasitized by various tiny braconid, ichneumonid, and chalcid wasps.

Fall webworm

• Eggs are laid on host trees

• Caterpillars feed on foliage and form silken tents nests on the tips of branches

Damage

• Defoliation, unsightly nests

Management

• prune out webs

• Contact insecticides may be used but the tents need to be broken open

• Natural enemies - Birds and many insect predators and parasitoids attack the larval stage.

Viburnum leaf beetle• Eggs are laid on the undersides of

new terminal growth

• Larvae go through three instar stages

Damage

• defoliation

Management

• Cultural controls adults –plant resistant varieties, remove egg infested twigs, foil larvae

• Chemical controls– Neem (small larvae)

• Biological control – predators feed on viburnum leaf beetle larvae including lady beetle adults and larvae, lacewing larvae and spinedsoldier bugs nymphs. The lady beetle adults and spined soldier bug adults also eat adult viburnum leaf beetles.

Lawn

• Ants

• Sod webworm

• White grubs

– Asiatic garden beetle, Japanese beetle, May and June beetle, European chafer, oriental beetle

Ants• Several species of ants inhabit

home lawns

• Little Black Ant, The Pavement Ant, Cornfield Ant, Larger Yellow Ant

Damage

• constructing mounds or small hills

• Disrupting soil around roots of plants

Management

• Cultural controls rake or "wash" (with a water stream from the garden hose) on a regular and frequent basis ant hills that appear above the grass tops

• Biological controls- many natural enemies, including a variety of insect predators

• Chemical controls– spot treat ant hills with an insecticide

Hairy Chinch Bug• Eggs are deposited in leaf sheaths and

in the ground on roots of host plants

• nymphs complete a series of five molts before maturing into adults over a period of 4 to 6 weeks

Damage

• Grass starts to yellow, turn reddish brown, and eventually die.

Management

• Cultural controls endophyte-enhanced turfgrass seed

• Chemical controls– Conventional insecticides can suppress nymphs and adults Biological control – big-eyed bug is the primary predator of hairy chinch bug nymphs and adults

White Grubs

• Eggs are laid in the soil • Larvae feed on roots in the ground

• Damage

• Causes poor growth, stunted plants, feed on flowers and defoliate plants

• Management

• Cultural controls for grubs –withholding irrigation during peak adult beetle flight

• Biological control – few products that allegedly control grubs milky spore, insect parasitic nematodes and fungal pathogens

• curative” control- apply short residual products right after eggs have hatched (early to mid-august)

IPM

Monitoring

Proper Identification is key to success

Sooty mold on Ficus

Use an Insecticide to treat the scale not a fungicide to treat the sooty mold!

SUPPRESSION

Cultural Practices

• Observation

• Soil preparation

• Rotation

• Garden plan

• Thinning

• Watering

• Time of planting

• Sanitation

• Plant selection

• Resistant varieties

• Staking plants

• Avoiding injury to plants

• Mulching

• Weed Control

MONITORING

Monitoring

• Pheromone traps

• Growing Degree Days

• Visual counts

• Sweep nets

Monitoring

GDD = (Tmax + Tmin)/2 - Tbase ……………EQN 1.

European Fruit Lecanium Scale egg hatch 29-Jun 1073phenological event

European Fruit Lecanium Scale is a key soft scale insect pest of shade trees and other

woody ornamental plants

Mechanical & Physical Controls

• Handpicking

• Traps

• Barriers

• Exclusion

kill a pest directly, block pests out, or make the environment unsuitable for it.

MANAGEMENT

Biological Controls

• Predators

• Parasites

• Pathogens

• Competitors

Chemical Control

• Last Resort– Use the least toxic options

• ALWAYS READ THE LABEL

Questions?