1. Insect Management for the Organic Producer
Eric J. Rebek
Associate Professor and State Extension Specialist
Department of Entomology & Plant Pathology
Oklahoma State University
@EricRebek

2. Organic Options for Pest Management
Integrated Pest Management (IPM) Strategies
Cultural control
Biological control
Physical/Mechanical control
Regulatory (legal) control
Chemical control (OMRI approved)

3. 1. Cultural Control
Prevention: avoiding pest problems by modifying growing practices
Crop rotation to break pest cycle
Insect (and disease) resistance/tolerance
Polyculture
Trap crops
Sanitation

4. Crop Rotation
YEAR 1
YEAR 2

5. Crop Rotation Corn rootworm (Diabrotica spp.) – eggs in soil
Avoid corn following corn
Note: Populations of Western corn rootworm and northern corn rootworms have adapted to corn-soybean rotations
Wireworms – larvae in soil
Avoid highly susceptible crops (e.g., root crops, corn, melons) following grassy sod or small grains
Note: some species remain as larvae for 3-6 years

6. Crop Rotation White grubs (Phyllophaga spp.) – larvae in soil
Avoid corn, potatoes, strawberries following grassy sod
Note: some species remain as larvae for 2-3 years
Colorado potato beetle (Leptinotarsa decemlineata) – adults in soil
Avoid repeated plantings of tomatoes, potatoes, or eggplant
Note: great distances and barriers to movement may be needed for adequate control

7. Insect Resistance/Tolerance
Insect-resistant crop varieties
Bt corn
Transgenic resistance to caterpillars (e.g., corn earworm)
Glandular-haired alfalfa
“Hairy” stems of certain alfalfa varieties inhibit potato leafhopper

8. Polyculture Intercropping, cover crops, etc. Crop diversification can:
Reduce attractiveness of crops to pests that specialize on certain crops
Plant Apparency Hypothesis
Increase abundance and diversity of natural enemies that feed on pests
Natural Enemies Hypothesis

10. Trap Crops Non-crop plants more attractive to pests than cash crop
Interplanted within crop or around perimeter of crop

11. Trap Crops
Sorghum and sunflower – leaf-footed bugs in southern tomatoes
Mustard – harlequin bugs in collards and other cole crops

12. Trap Crops Wide variety of species – stink bugs in many cash crops
Hubbard squashes – cucumber beetle in cash crop squashes

13. Sanitation Crop debris serves as harborage for pest insects
Remove and destroy debris
Burial, soil incorporation

14. Predators, Parasites, Pathogens
2. Biological Control
The 3 P’s:
Predators, Parasites, Pathogens

15. P R E D A T O R S

16. Predators
Predators: larger than their prey, eat many prey, fast moving, generalist eaters

17. Where is the predator? (bigger, fewer)
Lady beetle adult feeding on aphids…
White exoskeletons of aphids can be called aphid ghosts.
Tell tale signs that the beetle is a predator.
One beetle many aphids
Aphid in its mouth.
What do laby beetles eat?
Both adults and larvae eat aphids, scale insects, mealy bugs, mites, and insect eggs.

19. Tulsa County Master Gardeners
Which is the predator? The big spider is eating the fly… (bigger= predator)
Spiders are helpful, they eat flies---- and anything else that comes into their field of vision.
Oklahoma State University
Tulsa County Master Gardeners

20. P A R A S I T O I D S

21. Parasites (Parasitoids)
Parasitoids: smaller than prey, kill only one host, larvae are sedentary, many are specialists
Parasitic wasps
Parasitic flies

22. This tomato hornworm has not been spit upon
This tomato hornworm has not been spit upon. Rather, it is covered with pupae of a parasitic wasp.
The caterpillar is about 1/2 the size it ought to be.
The pupae will hatch out adult wasp.
If you see a parasitized hornworm, you should probably leave it in your garden so the emerged wasp can attack other caterpillars. The wasp will not provide immediate control but will reduce population of hornworms.

24. P A T H O G E N S

25. Pathogens (Microbial Control)
Fungi
e.g., Beauveria bassiana, Metarhizium spp.
Bacteria
e.g., Bacillus thuringiensis
Nematodes
e.g., Steinernema spp., Heterorhabditis spp.
Protozoa
e.g,. Nosema locustae

27. Gibellula sp.
Erynia sp.
Spider
Leafhopper
Cockroach
Hymenostilbe sp.
Beauveria sp.
Beauveria sp.
Leafhopper
Beetle
Katydid

28. Biological Control (3 kinds)
Classical (Importation)
Reunite old enemies; introduce natural enemies from pest’s geographic origin
Augmentation
Add what you need; supplemental release
Conservation
Conserve naturally occurring natural enemies

29. Conservation Biological Control
Two main strategies:
Modify pesticide use to reduce exposure to natural enemies
Modify habitat in favor of natural enemy survival, longevity, and reproduction
Attract and retain naturally occurring predators and parasitoids in the crop
E-1023: Conserving beneficial arthropods in residential landscapes

30. How to Conserve the Good Bugs
Reduce amount/frequency of pesticide use
Apply when beneficials are not active
Use selective products (e.g., Bt for caterpillar pests)
Apply “sweet water” to attract natural enemies
Use plants that help feed or shelter beneficials

31. Beneficial Flowering Plants
Tansy Goldenrod
Coneflower Coreopsis
Sunflower Cosmos
Caraway Mustards
Dill Milkweed
Fennel Buckwheat
Yarrow Sweet Clover
Wild Parsnip Alfalfa
Fava Bean Hairy Vetch

32. 3. Physical/Mechanical Control
Three main methods:
Barriers (exclusion)
Behavior modification
Destruction or killing

33. Exclusion
Floating row covers and screens – cabbage maggot, flea beetles, cabbageworms
Adhesives and burlap – caterpillar pests and aphid-tending ants
Trenches – Colorado potato beetle (only those crawling, not flying)

36. Behavior Modification
Two general methods:
“Push-Pull” technology
Mating disruption

37. Push-Pull Technology
Repel (push) or attract (pull) insect pest away from crop
Use pheromones or other lures as baits
Trap crops can be considered a push-pull strategy
Visual attractants

38. Mating Disruption Grape Berry Moth (Mid May):
Place 250 to 400 Isomate-GBM ropes/A (use 400/A in high-risk vineyards)
Prevents mating for 90 days in warm southern states
Not generally recommended in OK because of small size of vineyards (< 5 acres)

39. Killing
Crushing
Traps
Temperature
Suction

40. Killing Crushing – squash bug eggs on foliage
Traps – boards placed between rows for squash bug nymphs and adults

41. Killing
Propane torches (flaming), hot-water immersion, steaming, solar heating – wide variety of insect pests
Suction – Colorado potato beetle, lygus bug
Care must be taken to not harm natural enemies

42. Additional Resources Association of Natural Biocontrol Producers
(Info on Biological Control)
National Sustainable Agricultural Information Service (ATTRA)
Sustainable Agriculture Research & Education (SARE)
IPM Oklahoma!
entoplp.okstate.edu/ipm (Info on IPM)