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 Tactics Main 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 area 3.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 Method Control Effectiveness Control Type Monitoring Effectiveness ExclusionHighPreventativeNone Habitat & Behav. Mod High Preventative & Curative None Physical Control ModerateCurativeModerate Mechanical Control LowCurativeHigh