by Mary Gardiner, Megan Woltz and Brett Blaauw. Presented at the 2012 MN Statewide High Tunnel Conference.

2. Pollination Decomposition Biological Control
© Jackie / Bugguide.net © wildlife-pictures-online.com © Peter Bryant

3. Use of natural enemies to keep pest populations low
Predators
Parasitoids
Pathogens

5. Predators Pests
Squash Bug
Squash bug lay eggs on
plant leaves/stems
Stink Bugs Cucumber beetles lay
eggs at base of stem and
soil near plant
Striped Cucumber Beetle
Ground Beetles Eggs likely fed upon by
generalist predators
Do predators provide
significant biological
Ants Spotted Cucumber Beetle control of pest eggs?
Lady Beetles

6. Pumpkin Pests – Biological Control of Eggs
• Spotted CB and Squash
Bug eggs studied
Spotted cucumber
• Live sterile colony eggs beetle eggs
on ground
glued to cards
– OPEN/CLOSED
treatments (4 reps)
– In the field for 48 hrs
Squash bug eggs
attached to plant
– July-August leaves

7. Pumpkin Pests – Biological Control of Eggs
Predators reduced squash bug Squash bug
eggs by 10% and spotted eggs eaten
by predator
cucumber beetle by 80%!!

8. Feather-legged Fly
Pests (parasitoid of squash bug)
Pest adults are attacked
Squash Bug
by parasitoid flies
Tachinidae
Do we detect significant
parasitism of pests in the
field?
Celatoria diabroticae and C. setosa Striped Cucumber Beetle
(parasitoids of cucumber beetles)
Spotted Cucumber Beetle

9. Pumpkin Pests – Biological Control of Adults
• Assessment of adult parasitism
• 2 collections of striped
cucumber beetle and squash
bug from each site, July –
August
• Raised for 8 days, then frozen
& dissected
Celatoria sp larval mouthparts

10. Pumpkin Pests – Biological Control of Adults
• 10-17% of adult
pests were
parasitized!
• Does not account
for number which
may have been
killed by parasitoids
and not captured

11. Integrated Pest Management (IPM) is the combined use of tactics to
manage a pest (insect, disease, or weed) in an economically and
ecological sound manner.
Biological control is an Physical
Physical
Control
Control
important and sometimes
undervalued component of
IPM
Integrated
Cultural
Cultural Biological
Biological
Control
Control Pest Control
Control
Diverse group of arthropods
Management
contribute to biological
control
Chemical
Chemical
This service is provided free Control
Control
to growers and can be
enhanced through habitat
management practices.

12. Biological Control – Habitat Management
How can you modify high tunnel production to provide
habitat for natural enemies?
What do these beneficial insects need?
• Alternative food/prey resources
• Shelter/nesting sites
In the video we will discuss: Mulching, Tillage Practices, Selective
Insecticide Use, Providing Additional Flowering Resources.

13. Typical resource-poor environment surrounding crop field.

14. The addition of flowers can provide resources in and
around the crop.

15. Natural enemies and pollinators feed on pollen and nectar from flowers
Native Bees
Predators
Parasitoid Flies

16. Feeding on pollen and nectar builds up populations, increases longevity
and reproductive potential of pollinators and natural enemies
Double egg laying and lifespan with
access to floral resources
(Shahjanan 1968)

17. Natural enemies feed on alternative prey within flowering plant habitats

18. Flowering plants provide shelter and nesting
sites for pollinators
Perennial habitats provide overwintering sites
both below ground & remaining foliage.
Bumble bee nesting site
Mason bee nests (native pollinator)

19. Flowering plants provide shelter and nesting sites for natural enemies
Perennial habitats provide overwintering sites both below ground &
remaining foliage.
Lady beetles overwinter in the soil
Mantid egg mass
Orb Weaver egg mass

20. Planting Flowering Plant Resources
Annual plant insectaries
Common species used in habitat management include sweet
alyssum, coriander, phacelia, dill, and buckwheat.
Pros –
High pollen and nectar production
Resources provided same year as planted
Low seed costs
Can be planted in rows within main crop
Can be re-established next to crop of choice each season
Cons-
Pay to establish each year
Only one type of plant, may not have long bloom period
Does not provide overwintering habitat if removed at end of season
Plants are not native species

21. Planting Flowering Plant Resources
Planting arrangements for annual plant insectaries
Strips within the main crop

22. Planting Flowering Plant Resources
Planting arrangements for annual plant insectaries
Phacelia hedgerow next to cabbage crop
Weedy plants allowed to
persist until crop
established
Buckwheat cover crop

23. Annual Sweet Alyssum (Lobularia maritima)

24. Planting Flowering Plant Resources
Perennial plant insectaries
Nearly endless diversity of plant choices. Much research had focused
on the use of native perennials to provide habitat for beneficial
insects.
Pros –
High pollen and nectar production
Can customize bloom period and species complex
Provide overwintering habitat
Establish once, benefit for several years
If natives are used enhances biodiversity
Provides food, nesting for other wildlife such as ground-nesting birds
Cons-
Seed costs greater than annuals
Plants take 2-3 years to fully establish
Cannot move planting annually

25. May – Year 1 Flower plot establishment

26. June – Year 1

27. May – Year 2

28. June – Year 2

29. May – Year 3

30. June – Year 3

31. August – Year 3

32. Top 10 observed natural enemies
2% 1% 1% 1%
Ant
4%
Long Legged Fly
5%
Syrphid Fly
33%
Spider
15% Green Lacewing (Egg)
Parasitoid wasp
Crane Fly
Dragon Fly
17%
Robber Fly
21%
Lightning Bug
Total number of insects = 1821

33. Planting Flowering Resources
Interested in designing an insect habitat?
Website: http://nativeplants.msu.edu
What plants are attractive?
Bloom phenology
Pest attractive?
How to plant and maintain

34. Next in this session…..
NEW Natural Enemies Video developed by GLVWG:
• Identification of key natural enemies
• Learn which pests key natural enemies attack
• Habitat management to enhance natural enemies on-farm
• Receive new ID guide to vegetable natural enemies
Presentation by Megan Woltz:
• How the farm landscape influences natural enemies and biological control