Assumptions Preventing Insect Problems in Organic Vegetable Systems Small acreages High value crops - vegetables Diverse production Follow organic guidelines Rick Foster Department of Entomology Organic Insect Management Principles of management are the same as conventional IPM (Integrated Pest Management) Only difference is that some options are not available Lack of very effective insecticides requires greater attention to prevention Integrated Pest Management a system in which a combination of methods is used to maintain pest populations at low levels while allowing for profitable production with minimal adverse effects on the environment (Foster and Flood, 2005) Integrated Pest Management Combination of methods Profitable production Minimal adverse effects Farm workers Non-target organisms Consumers The Life of an Insect Goal is to produce viable progeny Advantageous to produce lots of young 1
Challenges for Insects Finding a suitable mate Finding a suitable food source Finding suitable oviposition site (food source for young) Surviving abiotic challenges Surviving effects of natural enemies Rick Weinzierl will cover How can we exploit these challenges to reduce insect damage? Finding a Mate Most adult insect activity occurs at night Many insects communicate with chemicals pheromones Using Pheromones in Vegetable Pest Management Monitoring activity black cutworms Monitoring numbers corn earworms 10 moths per trap per night; corn silking Mating disruption diamondback moth and cabbage looper (larger plantings) Finding a Suitable Food or Oviposition Source Not all crops are equally attacked Not all varieties of a crop are equally attacked Timing is important Cultural practices are important Frequency of Insect Damage to Vegetables Never/Rarely Sometimes Usually/Always Choice of Varieties Carrot Green onion Lettuce Pea Radish Asparagus Beans Pepper Spinach Tomato Broccoli Cabbage Cantaloupe Cauliflower Cucumber Eggplant Potato Most important consideration is what varieties your customers want to buy Not as many examples of resistance to insects as diseases Cabbage thrips Sweet corn good husk cover: earworms, tarnished s, picnic beetles Squash Sweet corn 2
Timing Synchrony between insect s life cycle and plant phenology window of vulnerability Avoid some problems by planting later root and seed maggots Timing Synchrony between insect s life cycle and plant phenology window of vulnerability Avoid some problems by planting later root and seed maggots Avoid some problems by planting earlier corn earworms Cultural Effects A healthy, rapidly growing plant can usually tolerate more damage than one under stress A healthy, rapid growing plant can usually tolerate more damage than one under stress Too much organic matter will attract root and seed maggots crucifers, onions, beans, peas, corn, cucurbits Cultural Effects Cultural Effects A healthy, rapidly growing plant can usually tolerate more damage than one under stress Too much organic matter will attract root and seed maggots Too much nitrogen may attract more aphids and result in faster reproduction Some cultural practices make it harder to find the plants reflective mulches, straw mulch for potato beetle, row covers 3
Abiotic Effects Winter synchronizes pest populations by creating a common starting point B. R. Flood Abiotic Effects Winter synchronizes pest populations by creating a common starting point B. Flood Insect development is driven by temperatures warmer temperatures mean faster development Climatic events such as rainfall or drought can have a dramatic effect on insect populations Abiotic Effects Drought (along with hot weather) can result in outbreaks of mites Rainfall can wash insects and mites from plants Frequent rainfall may cause disease outbreaks in the insect population Additional Information: www.meisterpro.com Example: Green cloverworm 4
Specific Recommendations Not enough time to cover details For more specific information, contact : Indiana: Rick Foster, rfoster@purdue.edu Illinois: Rick Weinzierl, weinzier@uiuc.edu Ohio: Celeste Welty, welty.1@osu.edu Or your county Extension educator Plant Early Corn earworm or fall armyworm on sweet corn Aphid transmitted viruses on pumpkins Imported cabbageworm Cabbage looper Plant Late Root and seed maggots Seedcorn beetle Corn rootworms Mexican bean beetles Sweet corn Stewart s wilt vectored by flea beetles Sweet corn Stewart s wilt vectored by flea beetles Sweet corn husk cover: picnic beetles, corn earworm, tarnished Sweet corn Stewart s wilt vectored by flea beetles Sweet corn husk cover: picnic beetles, corn earworm, tarnished Snap beans: Blue Lake varieties are at higher risk of potato 5
Susceptibility to Hopperburn Sweet corn Stewart s wilt vectored by flea beetles Sweet corn husk cover: picnic beetles, corn earworm, tarnished Snap beans: Blue Lake varieties are at higher risk of potato Potatoes: susceptibility to hopperburn from potato leafhopper is Delrus most susceptible Norland Monona Norchip Atlantic Superior Norgold Russet Kennebec Red Pontiac Sebago Katahdin Russet Burbank Russet Norkotah Ontario Red La Soda Nooksack least susceptible Sweet corn Stewart s wilt vectored by flea beetles Sweet corn husk cover: picnic beetles, corn earworm, tarnished Snap beans: Blue Lake varieties are at higher risk of potato Potatoes: susceptibility to hopperburn from potato leafhopper is Potatoes: variation in susceptibility to potato leafroll virus Sweet corn Stewart s wilt vectored by flea beetles Sweet corn husk cover: picnic beetles, corn earworm, tarnished Snap beans: Blue Lake varieties are at higher risk of potato Potatoes: susceptibility to hopperburn from potato leafhopper is Potatoes: variation in susceptibility to potato leafroll virus Potatoes: Norgold and Norkota (and Norchip) more susceptible to corn borer injury than Russet Burbank Sweet corn Stewart s wilt vectored by flea beetles Sweet corn husk cover: picnic beetles, corn earworm, tarnished Snap beans: Blue Lake varieties are at higher risk of potato Potatoes: susceptibility to hopperburn from potato leafhopper is Potatoes: variation in susceptibility to potato leafroll virus Potatoes: Norgold and Norkota (and Norchip) more susceptible to corn borer injury than Russet Burbank Glossy or thick (Tropicana) leaves for diamondback moth on crucifers Sweet corn Stewart s wilt vectored by flea beetles Sweet corn husk cover: picnic beetles, corn earworm, tarnished Snap beans: Blue Lake varieties are at higher risk of potato Potatoes: susceptibility to hopperburn from potato leafhopper is Potatoes: variation in susceptibility to potato leafroll virus Potatoes: Norgold and Norkota (and Norchip) more susceptible to corn borer injury than Russet Burbank Glossy or thick (Tropicana) leaves for diamondback moth on crucifers Cabbage thrips 6
Sweet corn Stewart s wilt vectored by flea beetles Sweet corn husk cover: picnic beetles, corn earworm, tarnished Snap beans: Blue Lake varieties are at higher risk of potato Potatoes: susceptibility to hopperburn from potato leafhopper is Potatoes: variation in susceptibility to potato leafroll virus Potatoes: Norgold and Norkota (and Norchip) more susceptible to corn borer injury than Russet Burbank Glossy or thick (Tropicana) leaves for diamondback moth on crucifers Cabbage thrips Onions thrips (antibiosis and tolerance) Crop Rotation Corn rootworms not western corn rootworm in some areas Corn root aphid Wireworms and white grubs Colorado potato beetle Carrot weevil Root and seed maggots Field Location Soybean aphid on snap beans not near alfalfa (viruses) Thrips no cabbage or onion near small grains Colorado potato beetle ¼ mile from last year s potatoes Imported crucifer weevil on horseradish Pepper fields away from corn to reduce corn borers Plant away from dusty roads to reduce mite problems (or control dust) Plant leaf crops away from crops ready for harvest (leafminers) Asparagus fields away from alfalfa fields (s) Field Selection Poorly drained soils increase root and seed maggot problems Corn root aphid Tillage Root and seed maggots (green and animal manure and crop residue) Harlequin bug on crucifers (crop residue) Diamondback moth and imported cabbageworm on crucifers (crop residue) Aphids on cabbage (crop residue) Leafminers on leaf crops (crop residue) Squash bugs (crop residue) Squash vine borers (crop residue) Fertilization Root and seed maggots (organic matter) Limit N use on leaf crops (aphids) Excessive organic matter increases damage from springtails, symphylans and bulb mites on leaf crops and bulb mites on onions 7
Armyworm Stalk borer Cutworms Weed Control Leafminers on spinach Stink bugs on tomato or peppers Eliminate grassy action sites for corn borers Flea beetles on crucifers and leaf crops (don t kill weeds during season) Sanitation No cull piles of onions onion maggot No cull piles of potatoes Colorado potato beetle Roguing and removing virus infected potato plants (aphid vectors) Trap Crops Intercropping/Plant Diversity Colorado potato beetle (early or late) Early planted radishes as trap for flea beetles on other crucifers Collards around cabbage for diamondback moth control Alfalfa planted near celery for control (don t mow alfalfa) Squash bug and squash vine borer on squash and pumpkin Squash around muskmelons for striped cucumber beetle control Cover crop or weeds between rows for diamondback moth Cover crop or weeds between rows for aphids on crucifers Mulch Straw mulch for Colorado potato beetle Reflective mulches for aphids or thrips Black or clear mulch heats soil and reduces seedcorn maggot and wireworm damage to cucurbits Barriers Row covers for many pests Plastic-lined trenches for Colorado potato beetle 8
Irrigation Overhead irrigation for diamondback moth in early evening disrupts moths mating and egglaying behavior Corn leaf aphid (avoid drought stress) Thrips on snap beans (avoid drought stress) False chinch bug on horseradish Processing/Sorting Many pests of processed peas, sweet corn and green beans hand or electronic sorting Aphids on leaf crops wash off with water Fruitworm damaged tomatoes or peppers visual inspection Questions? 9