1. Preserving Beneficial Predators in the Home Garden
Mary Barbercheck and Jermaine Hinds
Penn State Department of Entomology

2. Ladybeetle and Syrphid on Buckwheat Flowers
Principles of IPM
Manage system for productivity and beneficial processes
Plant Positive vs. Pest Negative
Use of decision-making criteria before action (or no action)
Integration of all suitable control techniques in a compatible manner
Limited pesticides, only as last resort
Ladybeetle and Syrphid on Buckwheat Flowers

3. What are Natural Enemies?
Spiders
Ground Beetles
Predators
Parasitoids
Pathogens
Value of pest suppression
estimated at $6 billion per
year!
Damsel Bug
Parasitic Wasps
Beneficial Predators are insects and other arthropods that suppress pests by feeding or parasitizing unwanted pest organisms.
Large diversity of beneficial insects within and outside the insects. Includes mites, fungi, nematodes, and arachnida. Define each?
Predators – typically consume multiple prey items whole
Parasitoids – complete life cycle as a parasite within the host or pest insect.
Pathogens – Disease causing organisms that kill pest insects can include fungal and bacterial pathogens (Seedcorn maggot parasite, Bacillus thuringencis).
Insect-parasitic Nematode
Predatory Mite
Insect-parasitic fungi

4. Natural Enemies of Plant-Feeding Insects
NESARE Soil Quality Workshop, 2006
Kutztown, PA
Natural Enemies of Plant-Feeding Insects
Predators – during development consume many insects
Predatory mites, ground beetles, predatory bugs, spiders, daddy-longlegs, centipedes
Ray R. Weil, University of Maryland

5. NESARE Soil Quality Workshop, 2006
Kutztown, PA
Natural Enemies of Plant-Feeding Insects
Parasitoids – during development consume one insect
parasitoid wasps, tachinid flies
Ray R. Weil, University of Maryland

6. NESARE Soil Quality Workshop, 2006
Kutztown, PA
Natural Enemies of Plant-Feeding Insects
Pathogens - cause disease in host organism
fungi, bacteria, viruses, protozoa, nematodes
Ray R. Weil, University of Maryland

7. NESARE Soil Quality Workshop, 2006
Kutztown, PA
Biological Control
Biological Control - Exploitation of natural enemies to hold pests below economically damaging levels
Conservation
Improve environment for
existing beneficial organisms
Augmentative & Inundative
Purchase and release
Usually not long-term
Improve environment for applied beneficial organisms
Pediobius wasp on Mexican Bean Beetle
Organic growers depend biological control to help manage their pests – taking advantage of food web interactions.
Conservation – using cultural methods to make the environment favorable for natural enemies.
Aphid “mummies” after parasitoid emergence
Ray R. Weil, University of Maryland

8. NESARE Soil Quality Workshop, 2006
Kutztown, PA
Conservation Biological Control
Goal: Improve environment for beneficial organisms and processes
Habitat Management: provide resource plants or habitats, e.g.,
cover crops
refuge strips of flowering plants
pollen and nectar resources required by many insect natural enemies
Adding plant diversity to a production system in space and time can help break pest cycles. Plants in the same family tend to have similar pests. Crop rotation, planting a series crops from different plant families in the same space in sequential seasons, helps deter the build up of pests that can occur when one crop species is planted continuously. Crop rotation, as described in Section in the National Organic Standards, is fundamental to good organic management and serves several functions. As stated in the rule, the producer must implement a crop rotation including but not limited to sod, cover crops, green manure crops, and catch crops. Crop rotation provides the benefits in addition to providing pest management in annual and perennial crops, including: maintenance or improvement of soil organic matter content; management of plant nutrients; and erosion control.
Spatial crop diversity can be achieved through crop rotation and various forms of polyculture, e.g., strip cropping, multiple cropping, or interplanting of plant species or varieties. A general effect of polyculture is a spatial mixing of crops, which can slow the build-up and spread of pests during the growing season. There are two main hypotheses to help explain how plant diversity acts to keep pest populations low. The first is based on plant apparency. It has been hypothesized that when a host plant is growing among non-host plants that the host plant is less apparent to an insect and, therefore, more difficult to locate. The second hypothesis is based on natural enemies. It has been hypothesized that plant diversity in a system increases the kinds of resources available to natural enemies of insects and encourages their occurrence, and predation and parasitism of insect pests.
An interesting application of crop diversity to control insect pests is perimeter trap cropping. In perimeter trap cropping, the crop being protected (“main crop”) is surrounded completely by a planting of one or two rows of a trap crop. The perimeter trap crop encloses the main crop and intercepts and concentrates incoming pests, where they can be killed. The trap crop may also serve as habitat for beneficial organisms. Perimeter trap crops must be present before or at the same time as the main crop to intercept pests. If the trap crop is maintained in a vigorous condition, the pest may not leave it. However, for maximum effectiveness, the perimeter trap crop should be treated with an allowed substance as soon as pests appear or begin to build-up in numbers.
Ray R. Weil, University of Maryland

9. Minimize Disturbance
Excessive tillage and pesticides may threaten and disturb beneficial insects
Destroy habitat
Directly kill insects
Insects use undisturbed areas for
foraging, refuge and
overwintering
Provide areas free of
disturbance
Conservation borders/strips:
Hedgerows, perennial
wildfllower strips, etc

10. Choosing the right plants
Compatible with growing system
Diversify!
Variety of flower colors, shapes and sizes
Choose different flower structures, tall an short
Choose species that ensure bloom throughout the growing season
When choosing insectary plants to promote and conserve beneficial insects in farm or garden consider:
Which plants are compatible with your operation annuals? Perrenials? Length of time in field? Secondary benefits (legume, weed suppression, reseeding)
When choosing plants, it is important to diversify your selection. Different insects are attracted to different types of flowers based on color, size, scent, structure. Offer a variety of flowers that can service a variety of beneficial insects. Also diversify plant species based on length of flowering time. It is important to choose species that bloom throughout the growing season and whose flowers appear when the targeted beneficial insects emerge.

11. Additionally, Quene Anne’s Lace, sweet alyssum, phacelia, clovers (red, crimson, white), canola, etc.

12. Caution Pesticide Use Pesticides may harm beneficial insects!
Avoid spraying when insects are active
Pesticides should be used as a last resort
Rely on cultural and biological control measures
Use targeted/ least toxic
pesticides

13. Some “Soft” Pesticides
NESARE Soil Quality Workshop, 2006
Kutztown, PA
Some “Soft” Pesticides
Safest
Insecticidal soap
Diatomaceous earth
Spinosad (Entrustr)
Various microbials
Particle films: bentonite, kaolinite (Surroundr)
Plant extracts and oils
Pheromones OK
Dormant and summer oils (narrow range petroleum, fish, plant)
Sulfur compounds
Botanicals
Pyrethrum (PyGanicr)
Neem
Ray R. Weil, University of Maryland

14. Considerations for pesticide use
NESARE Soil Quality Workshop, 2006
Kutztown, PA
Considerations for pesticide use
Have a plan: How and when you will react to a pest outbreak
Decide in advance your ‘action threshold’
Where possible, use biological controls
Know your soft pesticide choices: what’s safe, what’s labeled, what works, cost.
European Corn
Borer
Flea beetle
Ray R. Weil, University of Maryland

15. NESARE Soil Quality Workshop, 2006
Kutztown, PA
Microbial Controls
Insect Control:
B.t. var kurstaki
Beuveria spp.
(Mycotrol, Naturalis)
Metarhizium spp. (Met52)
Insect viruses
Beauveria
Insect Virus
Ray R. Weil, University of Maryland

16. Minimize Pesticide Non-target Effects
NESARE Soil Quality Workshop, 2006
Kutztown, PA
Minimize Pesticide Non-target Effects
Kaolin clay particle film
Registered on a variety of fruits and vegetables
Prevents insect feeding and oviposition
Approved for organic production
Ray R. Weil, University of Maryland

17. NESARE Soil Quality Workshop, 2006
Kutztown, PA
Biological Control of Pests: Augmentative
Apply large number of organisms in same manner as a pesticide
Introduces large numbers of organisms for relatively fast-acting control
May or may not become established
Application of a biological agent much like a pesticide.
Ray R. Weil, University of Maryland

18. NESARE Soil Quality Workshop, 2006
Kutztown, PA
Dispersal of Beneficial Arthropods
Consider the behavior of targeted beneficial insects.
Farmscaping to conserve natural enemies assumes that beneficial organisms will move out of refuge/resource areas into the cash crop to control pests there. Different natural enemies have a tendency to disperse different distances.
Ray R. Weil, University of Maryland

19. Summary Beneficial insects: How to conserve?
Important for pest suppression!
Require undisturbed and resource-rich habitat to thrive
How to conserve?
Minimize disturbance
Provide resources
Food (nectar, pollen)
Foraging sites
Overwintering sites
Minimize pesticide use
Rely on cultural and biological methods of control

20. Acknowledgements