Vegetable Insect Management PSS 124 Vegetable Crop Production Jon P. Turmel, State Entomologist VT Agency of Agriculture Waterbury, Vermont November 30,

Vegetable Insect ManagementVegetable Insect ManagementPSS 124 Vegetable Crop ProductionPSS 124 Vegetable Crop Production

Jon P. Turmel, State EntomologistJon P. Turmel, State EntomologistVT Agency of AgricultureVT Agency of Agriculture

Waterbury, VermontWaterbury, VermontNovember 30, 2006November 30, 2006

Transplants in the GreenhouseTransplants in the Greenhouse

Aphids – Aphids – Melon, Potato, Melon, Potato, Foxglove, Green PeachFoxglove, Green Peach

Dipterans – Dipterans – Fungus gnat, Fungus gnat, Shore fly, Humpbacked fly, Shore fly, Humpbacked fly, Moth fly, LeafminerMoth fly, Leafminer

Mites – Mites – Two-spotted spider, Two-spotted spider, CyclamenCyclamen

Whiteflies – Whiteflies – Greenhouse, Greenhouse, Silverleaf aka. Sweetpotato Silverleaf aka. Sweetpotato

aphid

AphidsAphids

green peach foxglove

melon potato

AphidsAphids

High Fecundity Rates: High Fecundity Rates: “Explosive” “Explosive” Parthenogenetically, Parthenogenetically, paedogenesis, sexualpaedogenesis, sexual

VectorsVectors

Oviparous, viviparousOviparous, viviparous

Resistance – Resistance – increased production increased production of an enzyme of an enzyme

Aphid MorphologyAphid Morphology

Aphid MorphologyAphid Morphology“Tubercles”“Tubercles”

Aphids Aphids Tended by ants Vectoring potato X virus

Sooty mold

Root aphids

Aphid ParasitoidsAphid Parasitoids

Aphid predatorsAphid predators

Adult lady bird beetles

Lady bird beetle larva

“flower fly” Adult syrphid

Syrphid larva

Crucifer Insect PestsCrucifer Insect Pests

Cabbage MaggotCabbage Maggot

Cabbage AphidsCabbage Aphids

Lepidopteran complexLepidopteran complex

* Diamondback Moth* Diamondback Moth

* Imported cabbageworm* Imported cabbageworm

* Cabbage Looper* Cabbage Looper

Cabbage MaggotCabbage MaggotDelia radicum (L.)Delia radicum (L.)

Cabbage MaggotCabbage Maggotlife cyclelife cycle

Overwinters as a pupa Overwinters as a pupa and emerges in mid-Mayand emerges in mid-May

Prefers cool, moist Prefers cool, moist weatherweather

First generation most First generation most damagingdamaging

2-3 generations/year2-3 generations/year

Larva completes cycle in Larva completes cycle in 3 weeks3 weeks

Feeds on all crucifers, Feeds on all crucifers, beets, celery and onionbeets, celery and onion

Adult

Cabbage MaggotCabbage MaggotManagementManagement

Monitor using yellow-pan Monitor using yellow-pan water trapswater traps

200 GDD200 GDD

Full bloom of Full bloom of Serviceberry, McIntosh Serviceberry, McIntosh and Cortland applesand Cortland apples

Cabbage MaggotCabbage MaggotManagementManagement

Protection of roots Protection of roots and stems and stems Insecticide application Insecticide application as drench pre or post as drench pre or post plantingplantingDrench (2-3) at five Drench (2-3) at five week intervalsweek intervalsIn furrow granularIn furrow granularSpunbonded row Spunbonded row covers (rotated only)covers (rotated only)

Cabbage aphidsCabbage aphids

Aggregated vs uniformAggregated vs uniformNo threshold at this time No threshold at this time but when head is formed but when head is formed the threshold is zerothe threshold is zeroSerious vectorSerious vectorSelective insecticidesSelective insecticidesSelective non-target Selective non-target insecticidesinsecticidesCheck for parasite pop.Check for parasite pop.Turnip-light oil reduces Turnip-light oil reduces mosaic virus transmissionmosaic virus transmission

Lepidopteran ComplexLepidopteran ComplexDiamondback Moth, Imported Cabbageworm and Diamondback Moth, Imported Cabbageworm and

Cabbage LooperCabbage Looper

Diamondback moth adult

Imported cabbageworm adult

Cabbage looper adult

Diamondback MothDiamondback MothPlutella xylostella (L.)Plutella xylostella (L.)

Overwinters ?Overwinters ?

Not known to be a Not known to be a vectorvector

Larva = 4 instars in Larva = 4 instars in 10-14 days10-14 days

Pupa = 14 daysPupa = 14 days

Female lays 160 eggs Female lays 160 eggs in 2 weeksin 2 weeks

larva

pupa

Diamondback mothDiamondback mothdamagedamage

Imported CabbagewormImported CabbagewormPieris rapaePieris rapae

egg hatching

larvapupa

Overwintering stage

4-8 days

8-20 days

24-31 days

Imported CabbagewormImported Cabbagewormdamagedamage

broccoli

cabbage

Cabbage LooperCabbage LooperTrichoplusia ni Trichoplusia ni (Hubner)(Hubner)

Eggs hatch in 3-4 days

Larva have 5 instars in 3 weeks, most damage is done in last 2 instars

As a pupa for about 2 weeks

adult does not overwinter in VT

Cabbage LooperCabbage Looperdamagedamage

cabbagebroccoli

Lepidopteran complexLepidopteran complexmanagementmanagement

Young plants = 35% Young plants = 35% infestedinfested

More mature = 20%More mature = 20%

10-15% on kale, collards 10-15% on kale, collards and mustardand mustard

Diamondback has Diamondback has become resistant, become resistant, alternate between alternate between effective treatmenteffective treatment

High volumes give better High volumes give better results (50 gal/A)results (50 gal/A)

Bt kurstaki, higher rate in Bt kurstaki, higher rate in cool conditionscool conditions

Bt aizawai works better Bt aizawai works better on resistant DBMon resistant DBM

MUST alternate with MUST alternate with synthetic insecticide or synthetic insecticide or spinosad (aerobic spinosad (aerobic fermentation by product fermentation by product of a soil bacterium) of a soil bacterium)

Avoid southern Avoid southern transplantstransplants

Potato Insect PestsPotato Insect Pests

Aphids – green Aphids – green peach, potato, peach, potato, foxglove, buckthorn, foxglove, buckthorn, melonmelon

Colorado Potato Colorado Potato BeetleBeetle

Potato leafhopperPotato leafhopper

Colorado Potato BeetleColorado Potato BeetleLeptinotarsa decemlineataLeptinotarsa decemlineata

Overwinters as an adult Overwinters as an adult in and around potato in and around potato fieldsfields

2 generations per year 2 generations per year with a third in some yearswith a third in some years

Both adult and larva feedBoth adult and larva feed

Female lays 300-500 Female lays 300-500 eggseggs

Implicated as a vector but Implicated as a vector but not yet confirmed not yet confirmed

larva

larval feeding

Colorado Potato BeetleColorado Potato BeetleAdult feeding

Newly hatched eggs

Female laying eggs

Larval feeding

Colorado Potato Beetle Colorado Potato Beetle ManagementManagement

Rotate to nonhost crops. Rotate to nonhost crops. This includes This includes overwintering sites that overwintering sites that border previous season border previous season plantingsplantings

Alternate different groups Alternate different groups of insecticides throughout of insecticides throughout the seasonthe season

Use mechanical barriers Use mechanical barriers such as trench traps such as trench traps and/or trap crops and/or trap crops

Determine Action Determine Action Thresholds. Crop can Thresholds. Crop can withstand 15% defoliation withstand 15% defoliation without effecting yieldswithout effecting yields

None of the present None of the present commercial cultivars of commercial cultivars of potato is resistant to the potato is resistant to the CPBCPB

Biocontrol including Biocontrol including insects, parasitoids and insects, parasitoids and predatorspredators

Colorado Potato BeetleColorado Potato BeetleTrench TrapTrench Trap

Plastic lined trench trapPlastic lined trench trap

Place next to overwintering areas at least Place next to overwintering areas at least one week prior to adult emergenceone week prior to adult emergence

1-2 feet deep and 6-24 inches wide at top1-2 feet deep and 6-24 inches wide at top

U or V shaped with walls 65-90 degree U or V shaped with walls 65-90 degree slopeslope

Colorado Potato BeetleColorado Potato BeetleAction Threshold DeterminationAction Threshold Determination

Walk the field in a ‘V’, Walk the field in a ‘V’, ‘W’ or ‘X’ pattern‘W’ or ‘X’ patternSelect 50 potato Select 50 potato stalks at random stalks at random intervalsintervalsCount adults, large Count adults, large larvae (>1/2 grown), larvae (>1/2 grown), small larvae (< half small larvae (< half grown)grown)

Compare counts to Compare counts to the table (on next the table (on next slide)slide)If numbers is high, If numbers is high, treatment is treatment is warrantedwarrantedIf low, no treatmentIf low, no treatmentIf between, no If between, no treatment but re-treatment but re-check in 3-5 dayscheck in 3-5 days

Colorado Potato BeetleColorado Potato BeetleAction Thresholds*Action Thresholds*

Life Stage Number of CPB per 50 StalksLow High

Adult

Small Larvae

Large Larvae

15 or fewer 25 or more



*Do not apply to B.t. products and are for midseason. Late season plants can tolerate more defoliation without affecting yields

Colorado Potato BeetleColorado Potato BeetleUse of Use of Bacillus thuringiensis tenebrionisBacillus thuringiensis tenebrionis

Most effective against 1Most effective against 1stst and 2and 2nd nd instar. instar.

First spray one-3 days First spray one-3 days after there is one or more after there is one or more egg masses per lant and egg masses per lant and 30% have hatched30% have hatched

If densely populated and If densely populated and eggs are hatching eggs are hatching continuously, reapply continuously, reapply after 5-7 days after 5-7 days

Or, wait for later instars to Or, wait for later instars to appear, treat with a single appear, treat with a single application of Provado or application of Provado or SpinTor the start your SpinTor the start your application a week later.application a week later.

Death with Bt may take Death with Bt may take up to 5 days but feeding up to 5 days but feeding ceases within one hour. ceases within one hour. Be patient!Be patient!

Potato leafhopperPotato leafhopperEmpoasca fabaeEmpoasca fabae

Potato LeafhopperPotato Leafhopper

nymph

adult

adult

adult


Overwinters along the Overwinters along the Gulf Coast on southern Gulf Coast on southern pinepine

Moves north on storm Moves north on storm fronts and arrives in VT fronts and arrives in VT mid-Junemid-June

Very low numbers can Very low numbers can cause significant crop cause significant crop losseslosses

Host of over 100 braod-Host of over 100 braod-leaved plantsleaved plants


Both nymphs and adults Both nymphs and adults cause damagecause damage

No disease is known to No disease is known to be transmitted by the be transmitted by the potato leafhopperpotato leafhopper

Causes “hopper burn”Causes “hopper burn”

Threshold is 10 nymphs Threshold is 10 nymphs per 100 plants. per 100 plants.

Currently, no cultural or Currently, no cultural or biological controls are biological controls are availableavailable

sweeping

hopper burn

#1 Enemy #1 Enemy (In my humble opinion)(In my humble opinion)

Tarnished Plant BugTarnished Plant BugLygus lineolaris Lygus lineolaris (Palisot de Beavois)(Palisot de Beavois)

Tarnished Plant BugTarnished Plant Bug

Feeds on over 300 Feeds on over 300 different plants (>50 of different plants (>50 of economic importance)economic importance)

Introduces a toxic saliva Introduces a toxic saliva into the plant while into the plant while feedingfeeding

Causes leaf distortion, Causes leaf distortion, ‘black joint’, scarring, ‘black joint’, scarring, discoloration, bud discoloration, bud abortion, dwarfed and abortion, dwarfed and pitted fruitpitted fruit

Tarnished Plant BugTarnished Plant Bug

egg

nymph

Bio-controlBio-control

Peristenus digoneutis

Tarnished Plant BugTarnished Plant BugDamageDamage

Celery

Tomato

Amaranth

Eggplant

Tarnished Plant Bug Damage in Tarnished Plant Bug Damage in StrawberryStrawberry

Corn Insect PestsCorn Insect Pests

European Corn BorerEuropean Corn Borer

Corn EarwormCorn Earworm

Northern/Western Northern/Western Corn RootwormCorn Rootworm

Fall ArmywormFall Armyworm

Black CutwormBlack Cutworm

Common ArmywormCommon Armyworm

European Corn BorerEuropean Corn BorerOstrinia nubilalisOstrinia nubilalis

Feeds on over 200 wild Feeds on over 200 wild and herbaceous plantsand herbaceous plants

Different strains cause Different strains cause different types of damage different types of damage to cornto corn

Vector of shank, stalk and Vector of shank, stalk and ear rot fungiear rot fungi

1-2 generations/year1-2 generations/year

European Corn BorerEuropean Corn Borerdamagedamage

beans

Bell pepper

popcorn

wheat

European Corn BorerEuropean Corn Borereggseggs

black headed stage

newly hatching eggs

egg mass on corn leaf

European Corn BorerEuropean Corn Borerlarvaelarvae

5 instars

1st instar feeding

larval feeding on ear


shot holes larval tunnel in midrib

larval tunnel in ear stalk

larval tunnel in stalk


Pupae in stalks

European Corn BorerEuropean Corn BorerPlowing down in fall…was the LAW!Plowing down in fall…was the LAW!

75% of the overwintering larvae in a corn 75% of the overwintering larvae in a corn field can be eliminatedfield can be eliminated

European Corn BorerEuropean Corn BorerScoutingScouting

Pulling whorl Unfolding whorl

Scouting for eggs Blacklight trap


No need to survey No need to survey before corn is knee before corn is knee high because of the high because of the high concentration of high concentration of DIMBOA- kills young DIMBOA- kills young larvaelarvae


When corn is When corn is pretassel and 15% of pretassel and 15% of these young tassels these young tassels show damageshow damageEarlier treatments are Earlier treatments are of no valueof no value22ndnd generation in mid- generation in mid-July to Sept. will July to Sept. will attack ears. Must attack ears. Must protect developing protect developing earsears


Conventional corn whorl damage

Transgenic corn in same field

Corn EarwormCorn EarwormHelicoverpa zea Helicoverpa zea aka.aka. Heliothis zea Heliothis zea

Native to the AmericasNative to the Americas

Most destructive after E. Most destructive after E. Corn BorerCorn Borer

Does not overwinter in VTDoes not overwinter in VT

Molds become toxinsMolds become toxins

Larvae may destroy silk Larvae may destroy silk before pollination is before pollination is completecomplete

$$$ when severe$$$ when severe

Corn EarwormCorn EarwormAdult usually arrives mid-July Eggs in silk for 3 days

pupae Larva feeding for about one month

Corn EarwormCorn EarwormMonitoring for adults and treatment scheduleMonitoring for adults and treatment schedule

Pheromone baited heliothis traps

Blacklight trap

Any Questions?Any Questions?

Documents

Vegetable Insect Management PSS 124 Vegetable Crop Production Jon P. Turmel, State Entomologist VT Agency of Agriculture Waterbury, Vermont November 30,