3. Hybrid Sterility

• Males & Females of different strains can produce non-viable offspring

• Incompatible strains can be generated through several ways– Direct genetic manipulation (“Transposable

Elements”)– Microbially-mediated (Cytoplasmic

Incompatibility)

Example: Wolbachia in lower flies

Physical & Mechanical TacticsMain Categories

• Environmental Modification

• Physical Exclusion

• Direct control of pest individuals

These tend to be used in special situations such as structural IPM or with special types of pests such as vertebrates.

Environmental Modifications in Structures

• Eliminate conditions conducive to a pest infestation will reduce pest attractions to a particular area.

• These include: – Removing the breeding source if possible, – Eliminating moisture conditions, – Eliminating harborages, – Cutting back shrubs and tree limbs next to buildings,– Using proper lighting (light management) to draw

night flying insects away from the property.

Environmental Modification Categories

• Temperature – often used for stored products– Heat– Cold

• Water– Flooding– Dessication– Irrigation

• Light– Mulches

Flame weeders

Organic mulches were recently

living tissue

Inorganic mulches were never living. Gravel, rock,

plastic, landscape fabric, etc.

Exclusion – Used 4 Ways

1. Used to keep pests from entering an area or building

2. Limit movement within an area3. Isolating a recurring pest problem (e.g.

entrance or doorway)4. Isolating a highly sensitive area (e.g.

operating room).

Note: Exclusion is very often associated with structural pest management

Exclusion in Structures

• Doors fit & seal, windows screened, both kept shut.

• Caulking & other sealants used at:– Utility entrances (plumbing,

electrical, sewer)– Exterior (wood trim, brick

mortar, foundation cracks & crevices).

• Isolation of deliveries & waste.

Birds in structures are often managed via exclusion

Physical Exclusion in Fields

• Barriers: Effectiveness varies by pest– Mollusks– Arthropods– Birds– Mammals

• Traps– Weeds– Arthropods– Vertebrates

Barrier Examples

Slugs won’t cross copper

Netting and screens are often used

as an insect barrier

Floating row covers on cabbage

protecting against cabbage

butterflies

Trap Examples -- Click on picture for more detail

Pathogen trap for use in greenhouses or irrigation water

Numerous live traps for vertebrates can be found here

Slug trap

Physical Controls in Structures

• Thermal Controls (heat and cold treatment)

• Electrocution (zappers)• Microwave suspect materials

Using energy factors in the environment such as heat, cold, light, sound, x-rays, infrared rays, etc., to kill pests or attract them to a killing mechanism

Direct Control

• Hand picking, killing individually

• Some Traps• Vacuums• Hoeing• Shooting

Removing pests by hand or using mechanical devices to trap, kill, or keep them out

Hand Picking Examples

Trap Placement in Structures•Place close to walls, behind objects in dark corners, wherever pest activity seen.

•Place them so that pests following normal travel (usually close to a wall) will pass directly over the trigger.

• Leave traps untriggered until the bait has been taken at least once prevents rats or mice becoming trap-shy.

•Baits compete with other food sources.

Problems with Mechanical Control

• Generally more practical in small areas than large ones.

• Labor intensive• Cumbersome (e.g. must remember where traps

are located & service them)• Inefficient (removes only a small portion of pest

population)• Often viewed as inhumane• Traps are more useful as a monitoring

procedure.

Summary of Non-Chemical Methods

MethodControl

EffectivenessControl Type

Monitoring Effectiveness

Exclusion High Preventative None

Habitat & Behav. Mod

HighPreventative & Curative

None

Physical Control

Moderate Curative Moderate

Mechanical Control

Low Curative High