Under Glass: Greenhouse Pest Management

Dr. Carol SutherlandExtension Entomologist, NMSU &

State Entomologist, NM Dept. Agriculture

Greenhouses & Hoop Houses---Tall or SmallWhatever You Can Imagine

Greenhouses & Hoop Houses: What Can They Do?• ‘Extend’ your growing/harvesting seasons---more yield, income potential

• Start seeds earlier, have transplants for the field; add a ‘short crop’?

• Greenhouses vs hoop houses---Size? Design? Construction costs? Durability? Ease of maintenance & repair? Costs to operate?

• Environmental control? None vs cooling, heating; air circulation

• Downside of ‘farming indoors’? Common pests? Management opportunities?

…If you plant it…

…they will come…

Deer, Elk, Wild Hogs, Javelinas, Cattle, Etc.

Obvious destroyers of greenhouses, hoop houses, plants, etc.

Besides obvious destruction, whatever is leftis likely contaminated with feces, microbes

FENCING! Multiple fence barriers?

Pest Management Practices---Dr. Sam Smallidge, NMSU, Extension Wildlife Specialist

Mice, Squirrels, Pack Rats, Rabbits, Etc.

Evidence of activity: Plant loss, gnawing, feces, finding animals, trails, entry holes

Impacts: Microbial contamination! Food poisoning! Produce losses! Hanta virus foryou in some areas; plague?

Avoidance requires constant monitoring, attention to maintenance, quick responses to any infestation

Pest Management Practices for Rodents, Rabbits---Dr. Sam Smallidge, NMSU, Extension Wildlife Specialist

Sowbugs & Pillbugs

Land-dwelling, air-breathing crustaceans with chewing jaws

Adults & immatures can feed on/in compost, soil organic matter& plants (esp. seedlings, transplants, foliage, flowers, fruits)

Both are actively crawling and feeding at night, dawn---whenmoisture levels are usually higher

Limit moisture & organic matter in infested areas. Omit mulch around plants ‘at risk’Irrigate in early morning; soil dries before sunset?Use drip or furrow irrigation, rather than sprinklers?Raised beds??

Hand picking ineffective; no traps; no magic pesticide here

Snails & Slugs

UC IPM Project

Wikipedia

TAMU

Brown garden snail

Decollate snail

Common garden slug

Air-breathing mollusks; muscular mouths with rasp-like radula; bodiescovered with slime; muscular ‘foot’.

Brown garden snail et al. can overwinter in topsoil; mulch is protective.

BGS and slugs are plant feeders; decollate snail is omnivorous

Rasp holes in foliage, fruit, stems; leave shiny trails of slime

Decollate snail may feed on slugs, other snails but take years to limittheir reproductive capacity, numbers; can feed on plants, too

Get Certifier’s opinion/approval for othertreatments: copper bands, coppersulfate, iron phosphate

Consider Using Traps to Detect/Monitor Pests?

Thrips Leafhoppers Aphids Whiteflies

Fungus gnats Psyllids Leafminers

Remember: you must be able to identify the pest of interest!

ThripsVery tiny < 1/16” long; like folds,

crevices in foliage, flowers, buds

Immatures white; adults yellow,

tan to brown

Wings fringed; only 1 mandible

Rasp and suck plant sap; kill cells

Transmit pathogens—e.g.tomato

spotted wilt---dirty mouthparts

Control difficult to impossible….

Tomato Spotted Wilt VirusOn Tomato, Pepper, More---Requires Lab Analysis to

Verify

Destroy suspect

plants

Viruses have no

controls

Thrips Management

• Parasitoids? Thripobius luteus, commercially available but efficacy is ??

( snazzy, but save your money?)

• Predators? Conserve these (outdoor situations); permit entry into GH?

Green lacewings---easiest to find/see

Minute pirate bugs

• Plants affected by viruses?---pull them out & dispose 12

Common Aphids---usually cool weather pestsSucking, needle-like mouthparts

Host specificity: broad to narrow, by sp.

Weaken & wilt plants; can kill plants

Honeydew makers! Ants et al. arrive

Potential plant virus vectors (dirty mps)

Many have female only colonies

Live birth! 8-12 daily/30 days as adult

1 week from birth to ‘Mom’

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Pepper Viruses & Aphid Vectors

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Pepper Mottle Alfalfa Mosaic Cucumber Mosaic

Winged aphids

can take virus

from one field

or host plant to

another

Wingless aphids

can transmit

virus within fields,

among hosts

‘Dirty mouthparts’

Aphids in the GH or Hoop House?

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Forceful streams of water?

Predators, parasitoids?

Neem, neem oil, horticultural oil products?

NO TREATMENT FOR VIRUSES IN

PLANTS---OTHER THAN PULLING !

Aphidius ervi (Braconidae)

‘Mummy’

Green lacewing

Beet Leafhoppers – Curlytop Virus Vectors

London Rocket

(mustard weed) Beet Leafhopper---3mm long

Beet Leafhopper picks up Curlytop Virus from weeds & transmits it to popular veggies

Yes, curlytop CAN occur in GHs & hoop houses---from transplants

Spinach Beans Beets Peppers Melons, squash

Managing Beet Leafhoppers, Curly Top?

Yellow sticky cards---for detecting only

really have to identify pest correctly;

CANNOT ‘trap them out’

Insecticides? Not effective; hoppers can

transmit pathogens faster than

insecticides can act

Eliminate Weeds---reservoirs for disease;

staging place for new pests

Plant Extra Plants---destroy infected ones;

still have enough for your crop

Tomato/Potato Psyllid - Bactericera cockerelli

Native to North America (Central America and north)

Sucking mouthparts; ‘psyllid yellows’ may be actual disease! Candidatus Liberibacter solanacearum

Since 2009-2010, serious pest in potatoes in western U.S.; also pests of tomato, peppers, eggplant (?) (Solanaceae)

Life cycle = about 4-5 weeks at summer temps.

Females may lay 30-250+eggs/each (inserted into host plant)

Abt. 1/16”; appears as black dot

Eggs minute,stalked

Nymphs flat,

slow moving

Series of nymphs, very flattenedNymphs on undersideof leaves

Potato---Especially

Ugh –ly, yucky taste, too

More Impacts of Tomato/Potato Psyllid

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Vein greening in tomato (CO) Honeydew globs from psyllid

feedingtomato & pepper

Vegetable Leafminer(Diptera, Agromyzidae, Liriomyza spp.)

Damaging Stage: larva mines foliage

Adult fly: abt. 1/16” long; yellow &black; red compound eyes

Maggot: 1/8” long at maturity

Evidence: minute white dots on foliage; serpentine, silvery mineyellowish maggot in mine

Numerous mines in foliage can cause leaf loss,fruit sunburn, decreased growth or fruiting

Variety of natural enemies for larvae; ignore?Or not?

Insecticide Resistance IS a possibility

Whiteflies: Greenhouse, Silverleaf, Sweet Potato • Adults minute (2mm), white, ‘moth-like,’

‘swirling flight,’ sucking mps; many hosts

• Nymphs immobile, scale-like, sucking mps

• Chlorosislethal; honeydew; sooty mold; virus vectors

• Common vegetable hosts (among others) include:

Cucurbitaceae: squash, melons, cukes, pumpkins

Solanaceae: tomato, eggplant, potato, peppers

Malvaceae: okra

Fabaceae: beans

Asteraceae: lettuce et al.

Scott Bauer USDA-ARS; Silverleaf wf

David Cappaert, MI State Univ; Greenhouse wfAPS.net; Bemesia tabaci complex ‘pupa’

Whitefly Identification: Magnifying Glass!

Pay attention to the Greenhouse WF & Sweet Potato WF (Silverleafwill be essentially identical to Silverleaf)

ID of adults = Self explanatory

ID of mature nymphs/’pupae’ or cast skins (exuviae):

Greenhouse WF: pill-box like with vertical sides; projecting‘filaments’ elongated, readily visible on edges.

Sweet Potato WF (essentially the same as Silverleaf): thickerin the middle, thinner around all edges; no verticalsides; short, sparse setae around edges.

Source: Whiteflies in the Greenhouse, ENTFACT-456, Jen White.

Whitefly Management?There are natural enemies commercially available, e.g.

However, beneficials can be killed by insecticides, including ‘organic ones.’

Encarsia formosa Eretmocerus eremicus Delphastus catalinae

Trade Name (e.g.)

Active Ingredient or Category

OMRI? Effect on Biologicals

Botanigard Beauvariabassiana fungus

Yes Relatively harmless

AZA-Direct, Azatrol, Neem

Azadirachtin, neem

Yes Somewhat harmful

M-Pede Insecticidal soap

Yes Harmless to adults

Source: Whiteflies in the Greenhouse, ENTFACT-456, Jen White.

Remember: No control ofvirus-infected plants ispossible; pull them out &dispose

READ THE LABEL FIRST!

CALL YOUR CERTIFIER FIRST TO CONSULT, GET APPROVAL FOR USE!

Fungus Gnats

Richard Leung David Caeppart Whitney Cranshaw uga1455188 MSchmidt

Whitney Cranshaw

Whitney Cranshaw

Adults annoying; larvae feed on soil organic matter, small roots

Both can be very abundant; contaminate produce

Control? Azadirachtin (Aza-Direct, Azatrol), Beauveria bassiana (Naturalis-O),Pyrethrins (Pyganic)---READ THE LABEL! CALL YOUR CERTIFIER FIRST! THESEPRODUCTS CAN HARM OTHER BIOLOGICAL CONTROL AGENTS IN YOUR GH!

Flea Beetles(Coleoptera, Chrysomelidae, Several Genera)

Damaging stage: adult (chewing); <1/8”; wary Evidence: tiny chewed holes in leaves

Plants can outgrow damage

Flea Beetle Control*---if needed at allActive Ingredient Example, Trade

NameOMRI?

Azadirachtin Azatrol, Yes

Beauveria bassiana Mycotrol-O, Naturalis

Yes

Pyrethrins Pyganic Yes (only 2 formulations are OMRI approved—EC 1.4 & EC 5.0)

Spinosad Entrust Yes

*Realize that, if you have other biological control agents active in the growing area, they may be harmed by application of these materials.

READ THE LABEL FIRST!

CALL YOUR CERTIFIER FIRST TO CONSULT, GET APPROVAL FOR USE!

Cutworms & ArmywormsAdults---night flying, many

species, gray, tan, brown; ‘miller

moths’

Larvae---dull colors, plump;

feed at night (chewing mps),

hide in soil litter & mulch by day

Beet Armyworm

Damaging Stage = Larva, chewing pest; bare,2-tone green, lateral ‘stripe’

Evidence on plant: ‘windows’ in leaves; blackgritty frass; fine silk or web; larva!

Many potential hosts among veggies

Adult active at night

Generalist predators & parasitoids will attackimmatures, but may not control numerous BAWs

Beet Armyworm Controls*---If needed

Active Ingredient Trade Name, e.g. OMRI?

Bacillus thuringiensis** Dipel, Biobit, Deliver, Agree, some others

Yes

Azadiractin Azatrol, Neemix Yes

Spinosad Entrust Yes

*Be aware that, except for Bacillus…, use of these other controls may harm otherBiological agents in the greenhouse

**affects many species of Lepidoptera, both moths and butterflies, but not all

READ THE LABEL FIRST!

CALL YOUR CERTIFIER FIRST TO CONSULT, GET APPROVAL FOR USE!

Cutworm, Armyworm (et al.) Management

Remove weeds from garden area

before planting (alternate food sources)

Kill armyworms & cutworms as you

find them

‘Solarization’ or ‘solar

soil sterilization’ over

previous winter or when

you’re not planting soon

May not be applicable

for GH & hoop house

planting

Cutworm Control*---if needed

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Active Ingredient Trade Name, e.g. OMRI?

Azadirachtin Aza-Direct Yes

Beauveria bassiana Naturalis Yes

Pyrethrins Pyganic Yes

Spinosad Entrust Yes

*Use of these products may affect biological control agents in the GH

READ THE LABEL FIRST!

CALL YOUR CERTIFIER FIRST TO CONSULT, GET APPROVAL FOR USE!

Spider MitesNearly microscopic; 8-legs; slow-moving; fine silk? Dusty undersides of leaves?

Paired mouthparts small enough to puncture/kill cells; ‘silvering’death

Hot, dry, dusty conditions favor these; numerous hosts

Green Light L&G Spray (spinosad), Trilogy (azadirachtin), M-Pede (soap) areOMRI approved but can harm other biological control agents. READ THE LABEL& CALL YOUR CERTIFIER! THESE ARE REALLY TOUGH PESTS TO CONTROL!

AntsVariety of species; smallest abt. 3mm;

largest abt. 6-7mm; black , reddish brown or combination; ‘workers’ always wingless; reproductive ants often larger than workers; reproductives winged initially (mating only), but remove wings later

Most species can bite (with jaws), many also sting (with stingers)

Social insects with very numerous workers

Impact: Microbial contamination; some chewing damage on fruit, honeydew;annoyance, stinging; in compost?

Harvester ant

Pyramid antFire ant

Naturalis, Pyganicmight be helpful

READ THE LABEL

CALL YOUR CERTIFIER!

One More Pest?TermitesFeed on wood, wood products---e.g. stakes,

posts (etc.) used in construction, raised beds, buried wood/cellulose debris or old stumps

Life Cycle: most likely termites will be ‘subterranean’ spp.; attack wood from soilcontacts, tunnel wood, ‘mud tubes’

Impacts: chewing jaws on workers, tunnelingweaken wood, wood failure

Replace wood with metal? Pipe? Sheet metal?

We Have Covered Elements of Integrated Pest

Management

Your Tools:

• Cultural:

– What sells? What cultivars are best adapted to your area?

– Water & Soil test. Apply ‘just enough’ soil amendments

• Physical/Mechanical:

– To mulch? Or NOT to mulch? (consider pest presence)

– Eliminate weeds; hand pick pests; strong stream of water, other?

– Sanitation---including GAPS (Nancy Flores, NMSU Food Technology)

• Natural Enemies: conserve/support; introduce?

• Insecticides: OMRI! READ LABELS! CERTIFIER APPROVAL!

• Documentation: Spend ‘quality time’ scouting your crops. Record observations,

treatments, results; pest IDs, calling your certifier for help…36

…a combination of biological, chemical and cultural pest control methods* that reduce

pest damage to acceptable levels while maintaining environmental integrity---guided by

National Organic Program principles & practices & NMDA-Organic Program.

Hoop House Construction for New Mexico:12-ft. x 40-ft. Hoop House

Del Jimenez, Ron Walser, Reynaldo Torres, 2005, NMSU CES Circular 606

Quote from the end of p. 4:

“By choosing selective low-profile fruits and vegetables that withstand cold temperatures, it

is possible to grow most of the year without the use of heating equipment and electricity.

These structures, with special plastic covers, can keep inside temperatures 4º to 6º F

warmer than outside temperatures, and with a row cover made from specially improved

webbings over the crop, another 4º to 6º F increase can be obtained.

With these structures one can make farming of food crops affordable, profitable and fun all year around….”

Row Covers? Can Retain Heat, Insulate Plants

Order this material from on-line sources

When all else fails…..check out Amazon.com

My Contact Info:

• Dr. Carol Sutherland

• Extension Plant Sciences

• N140 Skeen Hall, NMSU

• Las Cruces, NM

• csutherl@nmsu.edu