3/30/17
Lecture 4
Good Bugs of the Farm,
Garden, and Backyard
University of Wisconsin–Madison
Insect Diagnostic Lab
What are Beneficial Insects?
§ Insects that provide ecosystem services to humans
§ Benefits provided to humans by nature
§ Biological control (i.e., predators & parasites)
§ Decomposition, nutrient recycling
§ Pollination
§ Etc.
University of Wisconsin–Madison
Insect Diagnostic Lab
What is Biological Control
Biological Control
The use of biological agents (i.e., non-chemical) to
manage pest populations
“Using mother nature against pests”
1) Increase populations of predators/parasites (direct)
2) Increase habitat for beneficials (indirect)
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Insect Diagnostic Lab
Increasing Populations of Beneficials
§ Some biocontrol organisms are commercially available
§ Results can vary greatly
From one supplier:
“Releasing parasites is fun and something
University of Wisconsin–Madison
the whole family can do together”
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
Habitat Diversity :
Low Diversity
Herbicide-treated area
Beneficial Insects
High Diversity
Conservation Strip (Flowers)
Corn
Corn
Corn
Corn
Soybeans
Wheat
Corn
Corn
Corn
Switchgrass
Barley
Alfalfa
Corn
Corn
Corn
Wheat
Corn
Soybeans
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Herbicide-treated
area
Insect Diagnostic Lab
Conservation Strip (Switchgrass)
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Can Biological Control Be Effective?
Low Diversity
High Diversity
§ Yes!. . .Under the right conditions
§ Cactoblastis moth and prickly pear cacti (Australia)
§ Gulls and Mormon crickets (1840’s)
§ Cottony Cushion Scale & Vedalia Beetle (1880’s)
More beneficials
University of Wisconsin–Madison
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
Predators: Beetles
Biological Control in the Landscape
§ Predatory insects can be very common in the landscape
Parasites
Predators
§ Beetles
§ True bugs
§ Flies
§ Lacewings and kin
§ Yellowjackets and wasps
§ Spiders
§ Wasps
Firefly Larva (w/slug)
Ground
beetles
§ Flies
§ Roundworms
(nematodes)
Pathogens
§ Bacteria
§ Fungi
Rove
beetles
§ Viruses
University of Wisconsin–Madison
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
Predators: Lady Beetles
Minute Pirate Bug
Predators: True Bugs
Damsel Bug
Multicolored
Asian Lady
Beetle
(Harmonia
axyridis)
Assassin Bug
Big Eyed
Bug
University of Wisconsin–Madison
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
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3/30/17
Predators:
Stink Bugs
Two-Spotted
Stink Bug
(Predator of Colorado
Potato Beetles
Predators:
Flies
Hover Fly
(Diptera: Syrphidae)
Robber Flies
Spined Soldier Bug
University of Wisconsin–Madison
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
Mantids
Lacewings
Adult
Larva
Two species in WI:
§ Chinese Mantis
§ European Mantis
Egg
Mass
Eggs
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Insect Diagnostic Lab
Bald Faced Hornets
University of Wisconsin–Madison
Insect Diagnostic Lab
Predators:
Wasps
Larva
Predators: Mites and Spiders
Predatory Mites
(Acari: Phytoseiidae)
Grass Spider (Above)
Wolf Spider (Below)
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Insect Diagnostic Lab
Paper Wasps and
Yellowjackets
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Parasites (Parasitoids)
§ Usually specialists (only kill one or a few hosts)
§ Can be ecto- or endo- parasites (external vs. internal)
Parasitic Wasps
§ Many species known
§ Tend to attack only a single specific host
§ Some have been purposely released for biocontrol
§ Same size or smaller than prey
§ Examples:
§ Wasps
§ Flies
University of Wisconsin–Madison
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
Parasitic Wasps
Parasites: Flies
Tachinid Flies
Pyrgotid Fly
and May/June Beetle
Mummies = Aphid “Shells”
University of Wisconsin–Madison
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
Pathogens
Parasites: Roundworms (Nematodes)
§ Many species known, some commercially available
§ Can usually infest many different hosts
§ Can be very sensitive to environmental factors
§ UV light, moisture
§ Many are highly specific, others can infect many hosts
§ Can be significantly influenced by weather
§ Wet, cool weather
more disease
§ Examples:
§ Fungi
§ Bacteria
§ Viruses
University of Wisconsin–Madison
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
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3/30/17
Pathogens: Fungi
Wet Weather: Diseases
§ Spread through spores
§ Most require high humidity
Fungus Killed
Spider
§ Some commercially available
Fungus Killed
Moth
Fungus
Killed
Gypsy
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Wisconsin–Madison
Insect Diagnostic Lab
Moth Caterpillars
Pathogens: Bacteria
§ Some are commercially available
§ Milky spore (Bacillus popilliae)
§ Bacillus thuringiensis
Fungus Killed
Fly
University of Wisconsin–Madison
Insect Diagnostic Lab
Pathogens: Viruses
§ Are extremely specific
§ Viruses exist for many insects, including pests such as
armyworms, black cutworm, and gypsy moth
Milky Spore
Infected
Non-Infected
University of Wisconsin–Madison
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
Dung Beetles
(Aphodius sp. and others)
Decomposers
Common
Decomposers
Sexton or Burying
Beetle (Nicrophorus sp.)
American Carrion Beetle
(Nicrophilus americana)
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Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
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3/30/17
Common
Decomposers
Common Decomposers (in Wood)
Stag and Leather
Beetle Grubs
Blow Fly
(Family Calliphoridae)
Roundheaded Borers
(Longhorned
Beetles)
Millipedes
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Insect Diagnostic Lab
Flatheaded Borers
(Jewel Beetles)
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Pollinators
§ Pollinator: any organism that moves pollen between flowers
Pollinators
Honey Bee
Bumble Bee
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Insect Diagnostic Lab
“Wild” Bees
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Squash Bee
Sweat Bee
Other Insect Pollinators
Moths and Butterflies
Wasps
Flies
Cellophane Bee
Beetles
Leafcutter Bee
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Insect
Lab Stewart
All Photos
on thisDiagnostic
slide by Christy
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Insect Diagnostic Lab
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3/30/17
Meet the Bees:
UWEX Pollinator
Factsheet: G4001
§ United States: ~4,000 species
§ Wisconsin: ~400 species
Honey
Bee
Bumble
Bees
Wild
Bees
(Sevaral Familes)
University of Wisconsin–Madison
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
Bee Biology:
What Do Bees Need to Survive?
1. Food
§ Nectar
§ Pollen
GroundNesting Bee
What’s Up With Pollinators?
§ Many pollinators face declines due to a variety of factors
§ Habitat loss & fragmentation § Agricultural practices
§ Diseases: fungi, viruses, etc. § Pesticides
§ Parasites: mites
§ Many other factors
2. Shelter
§ Ground nesters (most bees)
§ Hole/tube nesters (~1/3 of bees)
§ Cavity nesters (bumble bees, feral honey bees)
University of Wisconsin–Madison
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
Parasitic Mites of Honey Bees
How Can YOU Help Pollinators?
1. Use insecticides only when appropriate
§ Explicitly follow allow label directions
Tracheal Mites
Bee
infected
with virus
spread by
varroa
University of Wisconsin–Madison
mties
Insect Diagnostic Lab
Varroa Mites
2. Make your yard and landscape pollinator friendly
§ Diversity of flowers = diversity of insects
§ Seasonal blooming patterns
3. Provide nesting habitat
4. Educate yourself and get involved!
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Insect Diagnostic Lab
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Making the Landscape Pollinator Friendly
Pollinator.org
Guide: plants to attract bees
and other pollinators
§ Diversity of flowers = diversity of insects
§ Ideal situation: 3+ different flowers blooming at any time
§ Go native!
§ Native bees are adapted for native flowers
§ Some commercial flower cultivars (“double flowers”) have
little to no nectar or pollen and don’t offer resource for bees
§ Tolerate some weeds (i.e., in lawns)
§ Clover, dandelions, etc. can provide
nectar/pollen for insects
University of Wisconsin–Madison
Insect Diagnostic Lab
Making the Landscape Pollinator Friendly
University of Wisconsin–Madison
Insect Diagnostic Lab
Wisconsin Pollinator Protection Plan
§ Provide nesting habitat: many bees nest in hollow “tubes”
Inside look at a solitary bee nest
University of Wisconsin–Madison
Insect Diagnostic Lab
University of Wisconsin–Madison
Insect Diagnostic Lab
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