Title: Organic Pest Management
1Organic Pest Management
- Debbie Roos
- North Carolina Cooperative Extension
2Outline
- Organic Pest Management Philosophy
- Insect Management
- Gallery of Beneficial Insects
- Gallery of Pest Insects
- Pest Management Resources
3Organic Pest Management Philosophy
4Appropriate Technology
Organic?
Conventional?
5Organic Pest Management Approach
- pests are indicators of how far a production
system has strayed from the natural ecosystems it
should imitate - insect pests are attracted to a plant that is
weak or inferior - in a well-balanced system, massive pest outbreaks
are rare due to the presence of natural
predators, parasites, and disease agents
6Organic Pest Management Approach
- prophylactic, holistic approach vs. remedial
approach - not just treating symptoms
- pest problem usually indicates sub-optimal
growing conditions and imbalance - emphasis on biodiversity and optimal cultural
practices
7Organic Pest Management Example
- Conventional approach spray insecticide to
control caterpillars, which often results in a
secondary outbreak of aphids or spider mites
because beneficial insects such as lady beetles
and other predators are also killed - Organic approach enhance habitat for beneficial
insects to increase population, reduce stress on
crop plant, use adapted varieties, and use
non-chemical methods to control pests (Bt,
hand-picking, row covers, alternating planting
dates, traps, etc.)
8Cultural Controls
9Cultural Controls
- Resistant cultivars
- Crop rotation
- Companion planting
- Timing of planting
- Sanitation
- Soil Management
- Mulches
- Composting
- Tillage
- Flaming
- Trap crops
10Resistant Cultivars
- Some varieties may be less attractive to pest
species or tolerate more damage than others - Plant size, shape, coloration, leaf hair, cuticle
thickness, and natural chemicals (attractants and
repellents) can all affect pest susceptibility
11Resistant Cultivars
- Morphological characteristics include those plant
structures that interfere with insect movement,
feeding, or reproduction associated with that
plant - Examples include color, thickness of the cell
walls and plant tissue, surface wax, spines and
trichomes
12Resistant Cultivars
- Physiological defenses include plant-produced
compounds that deter certain pests e.g.,
pyrethrum, is derived from the blooms of an
African chrysanthemum - Some plants have specific color-related
resistance - Most insects are attracted to leaves in the
yellow-green color range. Healthy, dark green
leaves are less attractive than yellowing plants
under stress.
13Crop Rotation
- insects overwinter in soil and debris, reinfest
new crop if susceptible and build up populations - 3 questions to consider when deciding whether
crop rotation will help manage a pest - How long can the pest persist in the field
without any host - How capable is it of invading from other areas
- How well does it survive on other hosts when the
crop is not present - plant non-susceptible crop so pests have no food
- know your botanical families leave as much time
as possible between related crops
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15Companion Planting
- attractant crops - small-flowered - carrot
family, daisy family, mint family - catnip,
caraway, dill, fennel, hyssop, lemon balm,
parsley, rosemary, thyme, yarrow, etc. - repellent crops - catnip and tansy repel aphids,
Artemesia repels flea beetles??? - Lots of recommendations out there with little
scientific evidence need more study before
recommending some companion plants increase pest
populations
16Timing of Planting
- keep notes to record pest and disease outbreak
patterns - the first date you see a problem and
the coinciding phenological events - adjust planting schedule accordingly to avoid
peak pressure - experiment with different planting dates - e.g.,
to avoid corn earworm or flea beetle or squash
bug - plant crops susceptible to nematodes early or
late while soil temperatures are cooler
17Sanitation
- select healthy plants
- rogue and prune
- remove crop debris promptly to reduce
overwintering sites for pests - eliminate alternate hosts, but be careful about
timing
18Soil Management
- Healthy soils high in OM and with a biologically
diverse food web support plant health and
nutrition better than soils low in organic matter
and species diversity. Healthy plants are
generally less susceptible to pest damage. - Approximately 75 of insect pests spend part of
their life cycle in the soil. Healthy soils
contain many natural enemies of insect pests,
including insect predators, pathogenic fungi, and
insect-parasitic nematodes.
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20Soil Management
- A soils physical condition its level of
compaction, water-holding capacity, and drainage
all affect soil and plant health. - The chemical aspects of soils pH, salt content,
availability of nutrients, etc. can affect crop
health and pest susceptibility.
21Strategies for Improving Soil Health
- Increase soil organic matter
- Keep soils covered with cover crops and/or crop
residue to reduce erosion and protect from
extremes of moisture and temperature - Plan tillage operations carefully
22See Example of Seedcorn Maggotson Growing Small
Farms Website
23Mulches
- Plastic mulches that speed early season crop
growth can enhance plants ability to withstand
insect feeding - Reflective mulches can reduce thrips and aphid
populations in crops - Straw mulch can reduce problems with Colorado
potato beetle
24Tillage
- disrupts life cycle of pests and beneficials
- can expose pests to predators, the elements
- till before planting to control weeds that harbor
armyworms, cutworms, plant bugs, aphids - till in the fall to destroy overwintering sites
for flea beetles, corn borers, squash bugs, etc. - balance with need to maintain groundcover
25Flaming
- Technique aimed at overwintering Colorado potato
beetle - Propane burners used to quickly pass a flame over
young potato plants when beetles are on top - Does little harm to the crop when the plants are
less than 4-5 tall
26Trap Crops
- A trap crop is a crop that is planted to lure
insect pests away from the cash crop. - Successful use of trap crops can be challenging.
The trap crop must be more attractive to the pest
than the cash crop, and care must be given that
the pests in the trap crop dont later migrate to
the cash crop. Trap crops are not effective
against pests that are weak fliers (e.g., aphids)
or are wind-dispersed (e.g., spider mites). - In organic systems with fewer insecticidal
options, pests are often killed through crop
destruction. But the timing of crop destruction
is critical - Research on trap crops has revealed mixed results
for its use as a pest management strategy. - Example from NC SARE producer grant in mountains
trap crops in organic broccoli
27Trap Crop in Organic Broccoli
28Physical Controls
29Physical Controls
- Manual controls
- Physical barriers
- Baits, traps, and lures
30Manual Controls
- Hand-picking
- Mowing
- Pruning
- Shaking
- Water sprays
31Physical Barriers
- Bagging fruit
- Copper strips
- Crawling pest barriers
- Cutworm collars
- Floating row covers
- Mulches
- Trenches
- Trunk bands
32Baits, Traps, and Lures
- Bait traps
- Japanese beetle traps
- Pheromone traps
- Slug and snail traps
- Sticky boards
- Trap crops
- Water traps
33Biological Controls
34Biological Controls
- Beneficial animals and insects
- Beneficial microorganisms - Bt, milky spore,
Beauveria bassiana (fungus), Nosema (protozoan)
35Biological Control in Action
- Augmentation increase population through
purchase and release - Conservation increase existing populations
through habitat conservation and other means
36Organic PesticidesRescue Treatments
37Pesticides in Organic Production
- When cultural, mechanical, and biological
strategies are insufficient to prevent or control
crop pests, weeds, or diseases, a biological or
botanical substance or a substance included on
the National List of synthetic substances allowed
for use in organic crop production may be applied
to prevent, suppress, or control pests, weeds, or
diseases - The conditions for using the substance must be
documented in the organic system plan
38Pesticides in Organic Production
- If certified organic, must choose pesticide that
is approved for organic production - consult with certifying agency
- also consult OMRI
39Botanical Pesticides
- Plant-derived materials such as neem, pyrethrum,
rotenone, ryannia, and sabadilla - Characteristics of botanical insecticides
- break down rapidly in the environment
- some are more toxic than synthetic pesticides
- broad spectrum
- must be used carefully
- only neem and pyrethrum are approved for organic
production
40Pyrethrum
- extracted from a flower in the chrysanthemum
family - a contact poison with quick knock down
- controls aphids, beetles, caterpillars, thrips,
mealybugs - OMRI-approved products include Pyganic
41Neem (azadirachtin)
- extracted from the fruit of a tree grown from
India to Africa - works as a hormone mimic, repellant, stomach
poison and some fungicidal properties have been
reported - controls a wide variety of insects
- OMRI-approved formulations include AZA-Direct,
Agroneem, Neemix
42Microbial Pesticides
- Microbials tend to not be as toxic as botanicals
and are more selective and softer on beneficials - Limitations of microbials
- Slow host death
- Need favorable environment
- UV light and temperature affect persistance
- Bacillus thuringiensis (Bt)
- parasitic fungi - e.g., Beauveria bassiana
- parasitic nematodes e.g., Heterorhabditis
- Spinosad
43Bacillus thuringiensis (Bt)
- contains a toxin made by a soil bacterium
- has been incorporated into commercial plants to
make them insecticidal (not allowed in organic
production) - sprayed formulations sensitive to UV light best
applied late in the day - must be ingested to work
- Several OMRI-approved formulations
44Parasitic Fungi
- e.g., Beauveria bassiana
- The spores of the fungus germinate once they come
into contact with the insect pest, then the
fungus must penetrate the cuticle and infect the
body cavity to kill the pest - Effective on many insects including aphids,
thrips, whiteflies, and grasshoppers - Work best when applied at onset of infestation
- Takes a week or more after application to see
evidence of control - OMRI-approved formulations include Mycotrol,
Naturalis L
45Parasitic Nematodes
- semi-aquatic live and move in soil water
- sensitive to UV radiation and desiccation
- Heterorhabditis (Hb) vs. Steinernema (Sc)
nematodes - application - spray or irrigation drip,
fertigation aerial, watering can application
should be followed by irrigation dont apply
during hottest part of day but soils should be
gt60º
46Spinosad
- Derived from a soil-dwelling bacterium
- Controls beetle larvae, caterpillars, thrips,
etc. - Most effective when ingested rather than as a
contact insecticide - Fast-acting, better than Bt on caterpillars
supposedly not as soft on beneficials so use in
targeted areas - Entrust - Formulation approved for organic
production in many vegetables
47Inorganic Pesticides
- Diatomaceous earth
- Kaolin
- Insecticidal soap
- Horticultural oil
48Okay, Now Its Time to Look at Some Insects, so
First, A Little Entomology 101
49Insect Classification
- Kingdom - Animalia
- Phylum - Arthopoda
- Class - Insecta
- Order - Coleoptera
- Family - Coccinellidae
- Genus - Coleomegilla
- Species - maculata
50Some Insect Orders
- Coleoptera beetles
- Diptera flies
- Homoptera aphids, scales, whiteflies
- Hymenoptera bees, wasps, ants
- Hemiptera - bugs
- Lepidoptera butterflies, moths
- Neuroptera lacewings, antlions
- Mantodea praying mantis
- Odonata dragonfly, damselfly
- Orthoptera crickets, grasshoppers
- Thysanoptera thrips
- Isoptera termites
- Siphonoptera fleas
- Dermaptera earwigs
51Structure of a Typical Insect
52Insect Features
Wings
Antennae
Mouthparts
Legs
Ovipositors
53Insect Development Metamorphosis
- Complete
- Metamorphosis
- 4 distinct stages egg, larva, pupa, adult
- Examples beetles, butterflies, flies, wasps,
lacewings, fleas - Incomplete
- Metamorphosis
- 3 stages egg, nymph, adult
- Examples bugs, aphids, thrips, grasshoppers,
termites, earwigs
54Gallery of Some Common Beneficial Insects
55What are Natural Enemies?
- Organisms that kill, decrease reproductive
potential, or otherwise reduce the numbers of
another organism - How do they do this? Through predation,
parasitism, herbivory, competition, antibiosis
(when organisms secrete substances that inhibit
vital activities of other organisms)
56Beneficial Organisms
- Predators larva or adult hunts, attacks, and
consumes prey examples include lady beetles,
lacewings, praying mantids, syrphid flies,
assassin bugs, minute pirate bugs, spiders, and
predatory mites - Each one eats many insects in its lifetime
- Not picky eaters
57Beneficial Organisms
- Parasitoids immatures develop on or inside a
host, killing it as they mature they emerge as
adults and continue the cycle examples include
parasitic flies and wasps - Each one eats only one insect in its lifetime
- Usually very picky eaters
58Beneficial Organisms
- Pathogens colonize and kill host examples
include nematodes, bacteria, viruses, fungi and
protozoa - Weed Feeders weeds can be attacked by
arthropods, vertebrates, and pathogens (fungi,
viruses, bacteria, and nematodes)
59BeetlesOrder Coleoptera
60Beetles
- 1/3 of all animals 40 of all insects are
beetles - Hard opaque wing covers are called elytra
- Beetles undergo complete metamorphosis
- Larvae and adults have chewing mouthparts
- Larvae have well-developed heads and 3 pairs of
legs
61Lady BeetlesOrder ColeopteraFamily
Coccinellidae
62Lady Beetles
- Larvae and adults eat
soft-bodied insects such as aphids, mealybugs,
spider mites, caterpillars, insect eggs - Voracious aphid feeders!
- Two main body types
- Round (hemispherical)
- Oval
63Round Lady Beetles
64Seven-spotted Lady Beetle
2 white spots on thorax
7 spots in a 1-4-2 pattern
65Seven-spotted lady beetle lunches at the aphid
café
66Seven-spotted lady beetle larvae like aphids
too!
Larvae hatching
67Multicolored Asian Lady Beetle
Black spots form M
larva pupa
68Oval Lady Beetles
69Convergent Lady Beetle
Thorax has two converging white lines and a white
margin
larva and eggs
70Pink Spotted Lady Beetle
71Plant-feeding Lady Beetles
Squash beetle
Mexican bean beetle
larvae and pupa
parasitized mummy
72Other Predatory Beetles Order Coleoptera
73Ground Beetle
Larvae and adults attack aphids, slugs, snails,
cutworms, caterpillars nocturnal foragers
larva feeding on caterpillar
adult
adult feeding on snail
74Rove Beetle
Adults attack aphids, nematodes, flies some
larvae are parasitic on maggots
short elytra
75Soldier Beetle
Adults feed on grasshopper eggs, aphids, and
various caterpillars larvae feed on a variety of
insects and snails and slugs
dead fungus-infected soldier beetle
look-alike lightning bug
76Tiger Beetle
Adults attack many different insects
77Blister Beetle
Larvae feed on grasshopper eggs, adults feed on
foliage and fruits
striped blister beetle
margined blister beetle
78True BugsOrder Hemiptera
79True Bugs
- Two pairs of wings usually present
- Forewings modified to hemelytra, hindwings
entirely membranous - Mouthparts enclosed in a piercing-sucking beak
that curves beneath the body - Incomplete metamorphosis egg, nymph, adult
- Some groups (e.g., stink bugs) have scent glands
on the sides of thorax - Order includes both plant feeders and predators
80Predatory BugsOrder Hemiptera
81Minute Pirate Bug
adult feeding on egg
Adults and nymphs attack aphids, mites, thrips,
small caterpillars, and insect eggs
adult feeding on aphid
nymph
82Bigeyed Bug
adult
Adults and nymphs attack mites, thrips, flea
beetles, small caterpillars, and insect eggs
egg
nymphs
83Bigeyed Bug Look-Alikes
Boxelder Bug
Bigeyed Bug
Tarnished Plant Bug
Pestsmall head and eyesbright coloration
Pestsmall head and eyesdull coloration
Beneficialwide head, big eyesdull brown or
black
84Damsel Bug
Adults attack aphids, thrips, leafhoppers, flea
beetles, plant bugs, and small caterpillars
Adult (left) and nymph
85Assassin Bug
adult
eggs
Adults and nymphs attack many insects, including
flies, tomato hornworms, and other large
caterpillars
nymph
adults attacking caterpillar
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87Bee Assassin
88Assassin Bug Look-Alike
Leaf-footed bug
Assassin bug
Pestleaf shape on back legthin, hidden beak
Beneficiallong, thin, unadorned legsshort,
thick, curved beak
89Assassin Bug Molting
90Predatory Stink BugsFamily Pentatomidae
91Spined Soldier Bug
Adults and nymphs attack caterpillars, Colorado
potato beetle larvae, Mexican bean beetle larvae
Podisus adult attacking beetle larva
nymph attacking Colorado potato beetle larva
92Other Predatory Stink Bugs
Twospotted stink bug (Perillus bioculatus)
Anchor bug (Stiretrus anchorago)
Anchor bug feeding on asparagus beetle larva
nymph
93Pest and Beneficial Stink Bugs
beak structures of predaceous (left) and
plant-feeding (right) stink bugs
beak structure of brown stink bug and spined
soldier bug
94LacewingsOrder Neuroptera
95Green Lacewing
larva feeding on aphids
larva
Larvae attack soft-bodied insects including
aphids, thrips, mealybugs, scales, mites, and
caterpillars
larvae emerging from eggs
stalked eggs
adult
96Brown Lacewing
larva
adult
egg
pupa
97Other Predators
98Parasitic WaspsOrder Hymenoptera
99Parasitic Wasps
- Hymenoptera is the second largest group of
insects - Over 16,000 species, most of which are
beneficial, are found in the U.S. and Canada - Many parasitic wasps are so tiny that many new
species are discovered each year! - They range in size from over an inch to almost
microscopic - Parasitic wasps are the most important group of
natural enemies of pest insects - All Hymenoptera undergo complete metamorphosis
100Parasitic Wasps
- In parasitic wasps, the larval stage develops in
and kills a single host insect most adults have
a very high reproductive capacity, which makes
them efficient at suppressing pests - The behavior of parasitic wasps is quite complex
many attack only one species of host insect, or
a narrow range of similar hosts - Adult females are very efficient at locating the
specific hosts - Hosts include almost all groups of terrestrial
insects - Depending on the parasite species, virtually any
host stage can be attacked egg, nymph, larva,
pupa, adult - Most parasitic wasps are incapable of stinging
humans
101Braconid Wasps
Parasitize armyworms, cabbageworms, codling
moths, gypsy moths, European corn borers, beetle
larvae, flies, aphids, and other caterpillars and
insects
Braconid parasitizing a corn earworm
mummy of an aphid parasitized by Braconid wasp
Aphidius
Braconid larvae emerging from parasitized moth
larva
Braconid pupae on tomato hornworm
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103Ichneumonid Wasps
Parasitize caterpillars, wasps, and beetle larvae
104Scelionid Wasps
adult ovipositing in a stink bug egg cluster
Parasitize eggs of
caterpillars and bugs
parasitized stink bug eggs
105Encyrtid Wasps
Encarsia formosa parasitizes greenhouse whiteflies
Parasitize eggs, larvae, and pupae of aphids,
scale, beetles, caterpillars, and whiteflies
whitefly nymphs (black ones have been parasitized)
106Encyrtid Wasp (Copidosoma floridanum)
adult parasitizing a cabbage looper egg
Parasitize eggs of
caterpillars polyembryonic
adults emerging from a mummified cabbage looper
host
looper parasitized by Copidosoma curls into
S-shape after spinning its coccoon
107Trichogramma Wasp
adult parasitizing a moth egg
Parasitize eggs of many pests, especially moths
and butterflies
commercial Trichogramma wasps are shipped as
parasitized moth eggs glued to a card note
emerged adult near pencil point
parasitized eggs are darker
108Parasitic FliesOrder Diptera
109Parasitic Flies
- Flies are second only to the Hymenoptera in their
importance as parasites - An estimated 16,000 species of flies are
parasitic, about 20 of all known parasitic
insects - Unlike parasitic wasps, most species of flies do
not have a well-developed ovipositor that can
insert eggs into their host many parasitic flies
lay their eggs on plants which are then consumed
by the host
110Tachinid Fly
Parasitize cutworms, caterpillars, Japanese
beetle, squash bug, green stink bugs,
grasshoppers, and other pests
adult approaching a beetle larva
eggs deposited on top of Japanese beetle and tent
caterpillar heads
Tachinid larva emerging from caterpillar
adult laying an egg
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112Predatory FliesOrder Diptera
113Predatory Flies
- At least 20 fly families have species that are
predaceous as larvae or adults - In species with predaceous larvae, adults lay
their eggs singly or in scattered groups on
plants near colonies of mites or aphids
114Hover Fly
adult
Larvae attack aphids, scales, and other insects
hover fly larvae feeding on aphids
115Robber Fly
Adults and larvae attack a variety of
soft-bodied insects
adult
Aphid Midge
Larvae attack aphids
midge larva feeding on aphid
116Long Legged Fly
117The Fabulous Underworld
of a Tomato Canopy
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129PestsSee Photos on GSF Website at
http//chatham.ces.ncsu.edu/growingsmallfarms/i
nsects.html
130Growing Small Farms Website
- Organic Pest Management
- Other Resources
131Other Resources(see handout)