Natural Control of OK Garden Pests
Part I Colorado Potato Beetle Cabbageworms Cucumber Beetle Cutworms Aphid Slug/snail Root Knot Nematode Hornworms/Sphinx Moths
Part II Squash Bug Flea Beetle Squash Vine Borer Cucurbit Diseases Spider Mite Birds Corn Earworm Blister Beetle
2 Squash Bug Anasa tristis
Eggs and young nymphs
adult
Various nymphal instars 3 Squash Bug
• Very common in OK gardens • Loves pumpkin and squash • Present in large groups
4 Squash Bug
• 5 juvenile stages (4-6 weeks) • Youngest are bright green • Adults overwinter under plant debris, mulch or other shelter
5 Squash Bug damage
• Suck juices from leaves, sometimes fruit • Initial yellowing or wilting of leaves • Kill leaves and entire plants • Spread disease; Cucurbit Yellow Vine Disease
6 Squash Bug control
• Provide compost and fertilizer; healthy vines are better able to withstand attacks.
7 Squash Bug prevention
• Most effective method • Light-weight row cover upon germination or earlier • Remove when flowers form to let pollinators in.
Young pumpkins in 2011 starting out under a protective row cover tunnel
8 Handpicking
• Bugs disperse quickly when disturbed • Unpleasant odor when threatened or handled • Hand pick by knocking bugs into a bucket of soapy water
9 Handpicking
• Egg masses are usually on underside of leaves. • Eggs darken as they mature • Scrape eggs off or use duct tape to pull off eggs • Eggs hatch in 10-14 days, check weekly
10 Squash Bug control
• Squash bug parasites (flies) feed on nectar; good flower choices are:
Spirea Queen Anne’s Lace Tricopoda pennipes lays its eggs on squash bugs
11 Neem
• Start spraying Neem early, don’t wait for an infestation • Controls larva, repels adults • Spray every 7-10 days • To avoid burning foliage, do not apply in the peak of the day
Neem oils
12 Insecticidal Soap
• Insecticidal soap is safe and breaks down nymph exoskeletons • Spray every 7-10 days • Avoid spraying in the heat of the day • Don’t use on new transplants
Insecticidal soap Insecticidal soap + Neem
13 Pyrethrin
• Insecticidal soap + pyrethrin (toxic to bees, fish, cats and other wildlife—read instructions!) • Only lasts for a short time
Insecticidal soap+pyrethrin
14 Pyrethrins
Pyganic
15 Homemade Squash Bug Spray
From Old Timers: 2 Tbs Dawn soap 2 Tbs hydrogen peroxide 1 Tbs orange oil 4 Tbs 70% alcohol 3 gallons water
16 Squash Bug Plan
Plenty of compost at planting Row cover until flowers form Neem or insecticidal soap (weekly) Handpick adults and larvae into bucket Duct tape to remove eggs (weekly)
17 Squash Vine Borer Melittia cucurbitae
eggs
adults
Larva inside stem
18 Squash Vine Borer
• Looks like a red and black wasp • Common in OK gardens • Pest of squashes and pumpkins
Similar to male velvet ant
19 Squash Vine Borer
• Females lay eggs singly on cucurbit stems or leaves • Females may lay 150-200 eggs • Larvae bore into the stem shortly after hatching, feed 4-6 weeks • Pupate in an underground cocoon
20 Squash Vine Borer Damage
• Moist, yellow sawdust-like “frass” indicates the presence of a borer • Several may reside inside the stem of a mature plant.
21 Squash Vine Borer damage
• Borers can cause the plant to wilt, reduce plant vigor and may kill a young plant.
22 Beneficial Nematodes
Attack a wide range of ground dwelling insect larvae, including Squash Vine Borers. Steinernema carpocapsae is a great species for SVB.
23 Squash Vine Borer prevention
• A light-weight row cover keeps out borers and squash bugs • Remove when flowers form
24 Squash Vine Borer prevention
• Eggs take 7-14 days to hatch • Wipe stems weekly with a cloth moistened with water or insecticidal soap.
25 Squash Vine Borer prevention
• Spray insecticidal soap on a weekly basis to smother eggs
26 Spinosad
• Spinosad, may also help with eggs • Some people inject it into plant stems • Toxic to bees for 3 hours following treatment (when still wet) • Neem & Pyrethrin may also help
27 Squash Vine Borer removal
• Larvae can be removed • Gently slit open the vine to expose the caterpillar and remove it • Mound soil up over the wound • Remove badly infested plants
28 Squash Vine Borer Plan
Apply beneficial nematodes Row cover until flowers form Wipe eggs off stems weekly Spray insecticidal soap, neem, or Spinosad weekly
29 Spider Mites many species
egg
• Tiny arachnids look like moving dots, can barely be seen • Common in OK • Thrive in hot, dry conditions • Affect tomatoes, roses, apples, boxwood, blackberry, Mexican sunflower, cosmos
30 Spider Mites many species
egg
• Common and serious tomato pest • Feed by sucking plant juices • Found on undersides of leaves • Prefer older, lower leaves
31 Spider Mite damage
• Leaves may show mottled, yellow foliage. • Fine webbing may be visible. • Damage is more prevalent in hot, dry weather and on water stressed plants
32 Spider Mite control
• Not very mobile • Blast them off with a sharp spray of water from a hose • Concentrate on undersides of leaves
33 Spider Mite control
• Many insects feed on spider mites. • Broad spectrum insecticides can kill predators and cause mite populations to explode
Lacewing
34 Homemade Spider Mite Spray
From Julia Laughlin, Horticulture Department Head, OSU/OKC: 3 Tbs gentle dishwashing soap 3 Tbs vegetable oil 1 gallon of water Spray every 5 days
35 Store-bought Insecticidal Soap
• Spray weekly • Don’t forget to spray under leaves
36 Aromatic Oils
• Mite X (clove oil and garlic extract) • Neem Oil • Remember to spray underside of leaves. Spray weekly
37 Spider Mite Plan
Spray water on undersides of leaves Spray soap, Neem, and/or Mite X weekly
38 Corn Earworm Helicaverpa zea
egg
• Prefer corn but will feed on lettuce and tomatoes. Brassicas, asparagus, cucurbits and many other crops are susceptible • Eggs laid on foliage or corn silks • Larvae feed then pupate in the soil
39 Corn Earworm Life Cycle
egg
Can overwinter in OK
40 Corn Earworm Damage
egg • In an ideal world, corn earworms keep to the top part of the cob. • They can burrow into lettuce heads • Eat leaves, stem and fruit of tomatoes • Primarily feed on blossoms, buds and fruits.
41 Corn Earworm Damage
egg
• Sometimes they venture further down the cob • Damage to kernels can lead to bacteria and fungi
42 Corn Earworm prevention
• Bt, if ingested,egg is effective at killing caterpillars • Last year 67% of corn grown in America was genetically engineered to produce the Bt toxin
43 Applying Bt
egg
• Since gardeners don’t plant Bt corn, we have to apply it to the silks at just the right time. • Too early = reduced pollination • Too late = earworms get in
44 Applying Bt
• 1 part Bt to 20 parts vegetable oil egg (corn or soy) • Apply when silks begin to wilt and turn brown. • Add .5 mL, or about 5 drops from an eyedropper to the tip of each ear. • For large plantings there are store- bought applicators
45 Corn Earworm Damage
egg
• If a caterpillar still finds its way in, cut off damaged part prior to cooking
46 Flea Beetle
• Several species • Tiny, jumps out of sight when disturbed • Affect eggplant, arugula, Asian greens and other brassicas, many other crops
adult
47 Flea Beetle Damage
adult
Chew “shotholes” in leaves
48 Flea Beetle
adult
49 Flea Beetle Prevention
• Agricultural row cover works great for eggplant, arugula, Asian greens • Most crops affected by FB don’t need pollination so you can leave row cover on
Eggplant under row cover
50 Flea Beetle Control
• Beneficial nematodes • Prey on many types of pests with underground larval stage.
Adult Larva
Steinernema feltiae
51 Flea Beetle Repellants
Neem, Diatomaceous Earth, Kaolin Clay
52 Spinosad
• Works via contact & if ingested • Toxic to bees for 3 hours following treatment (when still wet)
53 Pyrethrins
• Products containing Pytrethrins may be effective • Toxic to fish, bees, cats and other wildlife; read instructions
54 Cucurbit Diseases
Cucurbit Yellow Vine Disease • Caused by bacteria • Transmitted by squash bugs • First seen in 1988 in OK
Eggs and young nymphs
adult
55 Cucumber Mosaic Virus
• Worldwide; widest host range of any plant virus • Can also affect peppers, tomatoes, spinach, lettuce, carrots… • Spread primarily by aphids
Eggs and young nymphs
adult
57 Cucumber Mosaic Virus
Symptoms: • Stunting of plants • Mosaic pattern of light and dark green or yellow and green • Yellow streaking or spotting • Yellowing of veins Eggs and young nymphs
58 Zucchini Yellow, Squash & Watermelon Mosaic Viruses
Symptoms similar to Cucumber Mosaic Virus
ZYMV-aphid vectored WMV-aphid vectored
59 SqMV-Seed or Cucumber Beetle Vectored
Mosaic Virus Management • Look for resistant varieties • Remove and discard infected plants in trash • Remove biennial and perennial weeds, virus can overwinter in them and be passed on to aphids
Eggs and young nymphs
adult
60 Mosaic Virus Management
• Control aphids and cucumber beetles (see last week’s class) • Aphids---neem, soap or neem/soap mix • Cucumber beetles---beneficial nematodes, kaolin clay, neem
adult
61 Birds
Eggs and young nymphs
Not uncommon for birds to eat all youradult fruit
62 Netting
Eggs and young nymphs
adult
Attach to a frame or drape over hoops.
63 Bird Scarers
Place every 10’
Use only when fruit is ripening or seeds areadult sprouting; move every week so birds don’t get used to it.
64 Blister Beetle Meloidae Family
Eggs and young nymphs
adult • Attack a wide range of crops; very gregarious • Larvae eat grasshopper eggs • Produce the chemical cantharidin
65 Cantharidin
• Produced by males, demanded by females when mating • Beetles can reflex bleed • Causes skin blisters • Blister beetles are common in alfalfa; toxin is stable in dried Eggsremains and young of nymphsbeetles • Small amounts can kill horses and other livestock if beetle remains are in their forage adult
66 Cantharidin
• One of the oldest aphrodisiacs, “Spanish Fly”; dating to Roman times • Marquis de Sade is said to have poisoned women with it in 1772 • Used as a poison; by the Medicis •Eggs Currently and young used nymphs in wart removal
adult Collecting Blister Beetles
67 Blister Beetle Control
• More of a problem in the country • Devour beans, chard, tomatoes, cucumbers…. • Many OK organic farmers rely on Pyrethrins for control • Spinosad may be effective Eggs and young nymphs
adult
68