Jon Turmel Vegetable Insect Management

Vegetable Insect ManagementPSS 124 Vegetable Crop Production: 

Vegetable Insect ManagementPSS 124 Vegetable Crop Production Jon P. Turmel, State Entomologist VT Agency of Agriculture Waterbury, Vermont November 30, 2006

Transplants in the Greenhouse: 

Transplants in the Greenhouse Aphids – Melon, Potato, Foxglove, Green Peach Dipterans – Fungus gnat, Shore fly, Humpbacked fly, Moth fly, Leafminer Mites – Two-spotted spider, Cyclamen Whiteflies – Greenhouse, Silverleaf aka. Sweetpotato aphid

Aphids: 

Aphids green peach foxglove melon potato

Aphids: 

Aphids High Fecundity Rates: “Explosive” Parthenogenetically, paedogenesis, sexual Vectors Oviparous, viviparous Resistance – increased production of an enzyme

Aphid Morphology: 

Aphid Morphology

Aphid Morphology“Tubercles”: 

Aphid Morphology“Tubercles”

Aphids : 

Aphids Tended by ants Vectoring potato X virus Sooty mold Root aphids

Aphid Parasitoids: 

Aphid Parasitoids

Aphid predators: 

Aphid predators Adult lady bird beetles Lady bird beetle larva “flower fly” Adult syrphid Syrphid larva

Crucifer Insect Pests: 

Crucifer Insect Pests Cabbage Maggot Cabbage Aphids Lepidopteran complex * Diamondback Moth * Imported cabbageworm * Cabbage Looper

Cabbage MaggotDelia radicum (L.): 

Cabbage MaggotDelia radicum (L.)

Cabbage Maggotlife cycle: 

Cabbage Maggotlife cycle Overwinters as a pupa and emerges in mid-May Prefers cool, moist weather First generation most damaging 2-3 generations/year Larva completes cycle in 3 weeks Feeds on all crucifers, beets, celery and onion Adult

Cabbage MaggotManagement: 

Cabbage MaggotManagement Monitor using yellow-pan water traps 200 GDD Full bloom of Serviceberry, McIntosh and Cortland apples

Cabbage MaggotManagement: 

Cabbage MaggotManagement Protection of roots and stems Insecticide application as drench pre or post planting Drench (2-3) at five week intervals In furrow granular Spunbonded row covers (rotated only)

Cabbage aphids: 

Cabbage aphids Aggregated vs uniform No threshold at this time but when head is formed the threshold is zero Serious vector Selective insecticides Selective non-target insecticides Check for parasite pop. Turnip-light oil reduces mosaic virus transmission

Lepidopteran ComplexDiamondback Moth, Imported Cabbageworm and Cabbage Looper: 

Lepidopteran ComplexDiamondback Moth, Imported Cabbageworm and Cabbage Looper Diamondback moth adult Imported cabbageworm adult Cabbage looper adult

Diamondback MothPlutella xylostella (L.): 

Diamondback MothPlutella xylostella (L.) Overwinters ? Not known to be a vector Larva = 4 instars in 10-14 days Pupa = 14 days Female lays 160 eggs in 2 weeks larva pupa

Diamondback mothdamage: 

Diamondback mothdamage

Imported CabbagewormPieris rapae: 

Imported CabbagewormPieris rapae egg hatching larva pupa Overwintering stage 4-8 days 8-20 days 24-31 days

Imported Cabbagewormdamage: 

Imported Cabbagewormdamage broccoli cabbage

Cabbage LooperTrichoplusia ni (Hubner): 

Cabbage LooperTrichoplusia ni (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 Looperdamage: 

Cabbage Looperdamage cabbage broccoli

Lepidopteran complexmanagement: 

Lepidopteran complexmanagement Young plants = 35% infested More mature = 20% 10-15% on kale, collards and mustard Diamondback has become resistant, alternate between effective treatment High volumes give better results (50 gal/A) Bt kurstaki, higher rate in cool conditions Bt aizawai works better on resistant DBM MUST alternate with synthetic insecticide or spinosad (aerobic fermentation by product of a soil bacterium) Avoid southern transplants

Potato Insect Pests: 

Potato Insect Pests Aphids – green peach, potato, foxglove, buckthorn, melon Colorado Potato Beetle Potato leafhopper

Colorado Potato BeetleLeptinotarsa decemlineata: 

Colorado Potato BeetleLeptinotarsa decemlineata Overwinters as an adult in and around potato fields 2 generations per year with a third in some years Both adult and larva feed Female lays 300-500 eggs Implicated as a vector but not yet confirmed larva larval feeding

Colorado Potato Beetle: 

Colorado Potato Beetle Adult feeding Newly hatched eggs Female laying eggs Larval feeding

Colorado Potato Beetle Management: 

Colorado Potato Beetle Management Rotate to nonhost crops. This includes overwintering sites that border previous season plantings Alternate different groups of insecticides throughout the season Use mechanical barriers such as trench traps and/or trap crops Determine Action Thresholds. Crop can withstand 15% defoliation without effecting yields None of the present commercial cultivars of potato is resistant to the CPB Biocontrol including insects, parasitoids and predators

Colorado Potato BeetleTrench Trap: 

Colorado Potato BeetleTrench Trap Plastic lined trench trap Place next to overwintering areas at least one week prior to adult emergence 1-2 feet deep and 6-24 inches wide at top U or V shaped with walls 65-90 degree slope

Colorado Potato BeetleAction Threshold Determination: 

Colorado Potato BeetleAction Threshold Determination Walk the field in a ‘V’, ‘W’ or ‘X’ pattern Select 50 potato stalks at random intervals Count adults, large larvae (>1/2 grown), small larvae (< half grown) Compare counts to the table (on next slide) If numbers is high, treatment is warranted If low, no treatment If between, no treatment but re-check in 3-5 days

Colorado Potato BeetleAction Thresholds*: 

Colorado Potato BeetleAction Thresholds* Life Stage Number of CPB per 50 Stalks Low High Adult Small Larvae Large Larvae 15 or fewer 25 or more 75 or fewer 200 or more 30 or fewer 75 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 BeetleUse of Bacillus thuringiensis tenebrionis: 

Colorado Potato BeetleUse of Bacillus thuringiensis tenebrionis Most effective against 1st and 2nd instar. First spray one-3 days after there is one or more egg masses per lant and 30% have hatched If densely populated and eggs are hatching continuously, reapply after 5-7 days Or, wait for later instars to appear, treat with a single application of Provado or SpinTor the start your application a week later. Death with Bt may take up to 5 days but feeding ceases within one hour. Be patient!

Potato leafhopperEmpoasca fabae: 

Potato leafhopperEmpoasca fabae

Potato Leafhopper: 

Potato Leafhopper nymph adult adult adult

Potato Leafhopper: 

Potato Leafhopper Overwinters along the Gulf Coast on southern pine Moves north on storm fronts and arrives in VT mid-June Very low numbers can cause significant crop losses Host of over 100 braod-leaved plants

Potato Leafhopper: 

Potato Leafhopper Both nymphs and adults cause damage No disease is known to be transmitted by the potato leafhopper Causes “hopper burn” Threshold is 10 nymphs per 100 plants. Currently, no cultural or biological controls are available sweeping hopper burn

#1 Enemy (In my humble opinion): 

#1 Enemy (In my humble opinion)

Tarnished Plant BugLygus lineolaris (Palisot de Beavois): 

Tarnished Plant BugLygus lineolaris (Palisot de Beavois)

Tarnished Plant Bug: 

Tarnished Plant Bug Feeds on over 300 different plants (>50 of economic importance) Introduces a toxic saliva into the plant while feeding Causes leaf distortion, ‘black joint’, scarring, discoloration, bud abortion, dwarfed and pitted fruit

Tarnished Plant Bug: 

Tarnished Plant Bug egg nymph

Bio-control: 

Bio-control Peristenus digoneutis

Tarnished Plant BugDamage: 

Tarnished Plant BugDamage Celery Tomato Amaranth Eggplant

Tarnished Plant Bug Damage in Strawberry: 

Tarnished Plant Bug Damage in Strawberry

Corn Insect Pests: 

Corn Insect Pests European Corn Borer Corn Earworm Northern/Western Corn Rootworm Fall Armyworm Black Cutworm Common Armyworm

European Corn BorerOstrinia nubilalis: 

European Corn BorerOstrinia nubilalis Feeds on over 200 wild and herbaceous plants Different strains cause different types of damage to corn Vector of shank, stalk and ear rot fungi 1-2 generations/year

European Corn Borerdamage: 

European Corn Borerdamage beans Bell pepper popcorn wheat

European Corn Borereggs: 

European Corn Borereggs black headed stage newly hatching eggs egg mass on corn leaf

European Corn Borerlarvae: 

European Corn Borerlarvae 5 instars 1st instar feeding larval feeding on ear

European Corn Borer: 

European Corn Borer shot holes larval tunnel in midrib larval tunnel in ear stalk larval tunnel in stalk

European Corn Borer: 

European Corn Borer Pupae in stalks

European Corn BorerPlowing down in fall…was the LAW!75% of the overwintering larvae in a corn field can be eliminated: 

European Corn BorerPlowing down in fall…was the LAW!75% of the overwintering larvae in a corn field can be eliminated

European Corn BorerScouting: 

European Corn BorerScouting Pulling whorl Unfolding whorl Scouting for eggs Blacklight trap

European Corn Borer: 

European Corn Borer No need to survey before corn is knee high because of the high concentration of DIMBOA- kills young larvae

European Corn Borer: 

European Corn Borer When corn is pretassel and 15% of these young tassels show damage Earlier treatments are of no value 2nd generation in mid-July to Sept. will attack ears. Must protect developing ears

European Corn Borer: 

European Corn Borer Conventional corn whorl damage Transgenic corn in same field

Corn EarwormHelicoverpa zea aka. Heliothis zea: 

Corn EarwormHelicoverpa zea aka. Heliothis zea Native to the Americas Most destructive after E. Corn Borer Does not overwinter in VT Molds become toxins Larvae may destroy silk before pollination is complete $$$ when severe

Corn Earworm: 

Corn Earworm Adult usually arrives mid-July Eggs in silk for 3 days pupae Larva feeding for about one month

Corn EarwormMonitoring for adults and treatment schedule: 

Corn EarwormMonitoring for adults and treatment schedule Pheromone baited heliothis traps Blacklight trap

Any Questions?: 

Any Questions?