Insect Pest Management in High Tunnel (short version)

Integrated Pest Management inHigh Tunnel Crops

Dr. Ayanava Majumdar (Dr. A)Ext. Entomologist &

State SARE CoordinatorAuburn, AL 36849

Tel: (251) 331-8416bugdoctor@auburn.edu

HT Training Workshops, AL, 2013

• Small size• Small food requirement• Rapid and prolific reproduction

– Parthenogenesis• Grow by molting (control over

growth rate)• Life stages feed on different

substrate

Why are INSECTS so successful?

Why are INSECTS so successful?

High Tunnel Environment• Season extension = Early onset of insects!!• It gets hot & humid (PASSIVE VENTILATION)• Heat shortens insect lifecycles. • It is very dry on leaf surface (NO RAINFALL)• High planting density & diversity (HOST PLANTS)

High Tunnel Basics

• Bottom line 1: Prevention is better than cure!• Bottom line 2: Manage insects when they are

small/low numbers!• Bottom line 3: ANY INTERVENTION IN INSECT

ACTIVITY IS BETTER THAN DOING NOTHING!!

What is it?

Greenhouse whitefly, Trialeurodes vaporariorum (flatenned wings)

• First reported from USA in 1870• Adults are 1.5 mm long, covered

with white waxy material• Piercing and sucking mouthparts• Eggs laid on plants• Crawlers or nymphs feed on one

location• 30 days for one generation• Higher temps may inhibit the

whiteflies• Biological control: Encarsia formosa

Silverleaf whitefly, Bemisia tabaci (tented wings)

What is it?Potato aphid, Macrosiphum euphorbiae

Green peach aphid, Myzus persicae

Monitoring/scouting techniques:Sample ten plants in several locationsYellow sticky traps at edge of fieldLike cool, dry weatherWatch for ants and lady beetlesET = 50% leaves with aphids

Host range: 40 host plants

What is it?Onion thrips, Thrips tabaci

Tobacco thrips, Frankliniella fusca

Monitoring/scouting techniques:Use sticky cards (yellow, blue)Bag and shake techniqueNo action thresholdUse resistant varieties (BHN 444, 589, 640, Bella Rosa)

Tomato spotted wilt destroys plantsHost plants: tomato, peanuts, cotton, beans

What is it?Monitoring/scouting techniques:

Monitor level of defoliation

Sample small plants with sweep net during morning hours

Observe activity of parasitoids, predators (sweep net)

ET = 5-10% defoliation early season, 25-30% defoliation mid-season

Flea beetles (many species)

Host plants: potato, tomato, peppers, broccoli, cabbage, okra, etc.

Spider mites

• Major pest of open field & high tunnel crops• Extensive webbing on leaves/stems• Rapid buildup in hot dry weather• Difficult to control with approved pesticides

Identification & ScoutingTwospotted spider mite (TSM):• Carry a 10X hand lens• Females are larger than males• Oval adults, eggs glued to webbing• Underside of leaves & leaf tips• Wide host range Twospotted spider mite

Tetranychus urticaeTomato russet mite (TRM):• Smaller than TSM• Carry a 14X hand lens• Adults are elongate• Infestation starts from lower leaves• Leave edges, stems, fruits (small)• Solanaceous host plants

Tomato russet miteAcilops lycopersici

Crop damage

TRM:– Greasy bronzing

(russet color)– Sudden dry out

(lower leaves)

TSM:– Leaf drying– Extensive webbing– Slight bronzing

• Polyphagous insect (tomato, pepper, cotton, soybean, alfalfa)

• Have many wild hosts – lambsquarter & pigweed

• Creamish or light-green caterpillar, 4 pairs of prolegs

• Black spot on thorax just above the leg

• Early instars feed voraciously

• Moths are attracted to weak plants

What is it?

Damage to pepper plant

Beet armyworm, Spodoptera exigua

Starting Point for IPM…• Emphasis on Pest Detection & Correct Identification:

– INSECT PHEROMONE TRAPS for improved scouting– Trap Catch = Pest Density X Pest Activity (Taylor, 1963)– Insect Monitoring Project in Alabama, 2009-2010

Corn rootworm trapSticky wing trap

Stink bug trap

What is it?Monitoring/scouting techniques:

Use a sweep net

Use pheromone trap (expensive? cumbersome?)

Intensify scouting at fruit setting

ET = 0.25 bugs per 10 plants (green fruit stage)

Southern green stink bug, Nezara viridula

Brown stink bug, Euschistus servus Lygus bug, Lygus

lineolarisStink bug feeding injury

Host: >52 plants

Integrated Pest Management (IPM) Tactics

What is IPM?• “Integrated pest management (IPM) is a threshold based decision management system which leads to judicious use of multiple pest control tactics.”

• IPM is currently insecticide-intensive…

• Major losses occur due to:

• Lack of early detection of insects

• Insecticide resistance by misuse

• Loss of natural control with insecticides

USDA National Organic Program Standards (applicable in gardening situation also!)

• Level 1: Systems-based practices (variety selection,

sanitation, crop rotation, weed control, trap crops*)

• Level 2: Mechanical and physical practices (barriers,

lures/traps, repellents, hand-picking, net house*)

• Level 3: Biorational & other material (OMRI

approved insecticides)

*Discussed later in this presentation

Trap Crop Applications

Sorghum trap crop on two sides of a high tunnel can act as barrier to pest migration.

Sorghum & sunflower trap crops ahead of a high tunnel.

Trap crop study for leaffooted bugs(Clanton, AL, 2012)

Obs. 1 Obs. 2 Obs. 3 Obs. 4 Obs. 5 Obs. 6 Obs. 70 0 0 0 0 00

18

42

1

4

19

11

20 0 00

22

0

3

DKB5400 (sorghum trap crop)NK300 (sorghum trap crop)Sunflower (trap crop)Tomato (main crop)

Insecticide treatment and/or manual removal in organic situation

(21 July) (4 Aug.) (5 Sep.)

Numbers indicate leaffooted bugs (LFBs) on 20 heads of trap crops and 20 tomato plants for comparison purposes. Trap crops planted on May 16. Main crop planted on June 1. Trap crop treated with Mustang Max (zeta-cyper. @ 4 oz/A) on Sept. 5, 2012. Result = 78% LFB control in 5DAT. Tomato main crop is attacked by LFBs after the trap crop is ineffective (in October).

(13 Aug.) (7 Sep.) (20 Sep.) (4 Oct.)

Manual removal in organic situation

Damage

Both adults and larvae feed on foliage by first making small holes; later serious defoliation

Defoliation of larvae on turnip Mass attack of adults on napa cabbage

Main cropTrap crop

Turnip

Napa cabbage

Field Trials-Managing YMLB with Trap cropSpring 2011

35 ft

Fabric mesh 30-50 as insect barrierMesh size depends on target insect & cost

Location: Baldwin County, AL Dimensions: 150 ft X 48 ft X 17 ftEntrance: Double door

First Net House in Alabama (2010)

Insect Netting Applications

Insect netting on the sides and front (improved air flow)

Use insect netting over the entire high tunnel frame

Nat

ura

l En

emie

s

25

Predators: – Ladybugs, Spiders

• General feeders• Eat several prey• Larger and stronger than the prey

Parasitoids (=parasites): – Wasps, Flies

• Specialist feeders• Kill only one host (pest)• Smaller than the host

Pathogens: – Bacteria, Fungus & Viruses

• Micro-organisms that cause diseases in insects

Who kills Pests?

http://www.harvesttotable.com/2012/06/parasitic-wasps-beneficial-insects/

extension.entm.purdue.edu

Flicker.com

Insecticide Mode of Action (MoA)Physical dessicant – kaolin clay, ash

Contact action – vegetable oils, horticultural oils, neem, pyrethrin, insecticidal soap, spinosyn, Beauveria, Metarhizium

Stomach action – Bt (Dipel)

Volatile action – Garlic Barrier, Cinnamite

Fruit quality with Xentari (Bt aizawai)(Cullman, 2012)

Untreated crop with 90% caterpillar damage &

irregular fruit size

Xentari foliar treatment with <20% caterpillar damage &

uniform fruit size

Fruit quality with Pyganic (pyrethrum)(Cullman, 2012)

Untreated check Pyganic foliar

90% fruit damage

30% fruit damage

Fruit quality with Xentari (Bta) + Pyganic(Late season treatment, Cullman, 2012)

Check plots Xentari + Pyganic foliar

High Tunnel Pest Management Tips• Practice sanitation and strict weed control• Regular irrigation, reduce stress• Scout weekly to find insect hot spots, then treat.• Choices: Conventional (drip) or Organic (foliar)• Organic approved i-cides:

– Bt products (Xentari®, Thuricide®)

– Spinosad (Entrust®, Monterey Spinosad®)

– Pyrethrin (Pyganic®, Natural Pyrethrin®)

– Neem with azadirachtin (Molt-X®, Neemix®)

– New products: Azera

• Use insecticidal oils carefully (do not use >85F)• Use a good quality backpack sprayer.

High Tunnel Pest Management Tips• Use biological control when possible.• Use biological control and organic insecticides at

the first detection, continue for 2-3 weeks.• Reduce insecticide use when using nonselective

insecticides.• Treat the bottom on leaves and soil below the

plants.• Mix fresh spray solution and calibrate sprayer.

Change nozzles when needed.

EXTENSION RESOURCES

Know the IPM Campaign!

Campaign items: Display magnets, bookmarks (4 designs), IPM exhibitions

Vegetable IPM Website

www.aces.edu/go/87

Alabama SARE Website

Join Vegetable IPM on Facebook!

Advantages: Live updates, interact with researchers, videos and photos, IPM contest

Join Commercial Horticulture on Facebook!

Advantages: Live updates, interact with researchers, videos and photos, IPM contest

The IPM Communicator(A FREE electronic newsletter)

To signup: Email bugdoctor@auburn.eduOr sign up today on the sheet provided!

Acknowledgements

Chris Becker, REA

Willie Datcher, REA

FUNDING SOURCES: USDA Organic Agriculture Program, SARE initiative, Specialty Crops Grant, Wallace Center