Insect Pest Management & Conservation in the

landscape

Adam Dale, PhDTurf & Ornamental Entomology

Entomology & Nematology Department

Turfgrasses provide several benefits & interact with everyone

• Water filtration• Carbon storage• Aesthetic enhancement

• Cooling• Erosion control• Many others…

Unfortunately…

Lawns are frequently attacked by insect pests…

• The evidence• Southern chinch bug, Blissus insularis• Southern & tawny mole crickets, Neoscapteriscus spp.• Tropical sod webworm, Herpetogramma phaeopteralis• Tuttle mealybug, Brevennia rehi• Fall armyworm, Spodoptera frugiperda• Several more…

Pest-damaged Lawns

• Increase pesticide applications and maintenance inputs (irrigation and labor)

• Provide reduced benefits (water filtration, cooling, carbon sequestration, aesthetic value)

• Incur additional costs to homeowners and lawn managers

Integrated Pest Management (IPM)

• Science-based, sustainable decision-making process that uses information on pest biology, environmental data, and technology to manage pest damage in a way that minimizes economic costs and risks to people, property, and the environment. – USDA, 2018

Incorporating multiple evidence-based strategies to preventively manage pests with

reduced inputs and non-target impacts

Integrated Pest Management

1. Identification2. Monitoring3. Decision making4. Intervention5. Evaluation

Arthropod I.D. Resources• IFAS EDIS and Featured Creature fact sheets

• http://edis.ifas.ufl.edu• https://entnemdept.ifas.ufl.edu/creatures/

• IFAS Entomology Insect I.D. Lab – Lyle Buss• http://entnemdept.ufl.edu/insectid/• ljbuss@ufl.edu, (352) 273-3933

• IFAS Nematode Diagnostic Lab – Dr. Billy Crow• http://nematology.ifas.ufl.edu/assaylab/index.html• NEMALAB@ifas.ufl.edu, (352) 392-1994

• Commodity-specific specialists around the state• http://entomology.ifas.ufl.edu/extension/• http://entomology.ifas.ufl.edu/people-directory/

• IFAS Extension Bookstore I.D. books / decks• http://ifasbooks.ifas.ufl.edu/p-153-helpful-harmful-harmless.aspx

Southern Chinch Bug(Blissus insularis)

• The most economically damaging insect pest of turfgrass in the southeastern U.S.

• Primary pest of St. Augustinegrass (S. secundatum)• Recent cases in bermudagrass & zoysiagrass

• Frequent recurring target of insecticide applications

Southern Chinch Bug (Blissus insularis)

• Sap-feeding pest• Eggs are laid singly in the thatch, at the crown, and

in leaf sheaths • Nymphs and adults occur together

L. Buss

1st instar 2nd instar 3rd instar 4th instar 5th instar Short-winged adults

Long-winged adults

Southern Chinch Bug• Plant growth declines; grass blades turn

yellow then brown; patches of grass die• Begins in dry areas, typically under full sun &

near impervious surface edges

Southern chinch bug cultural control

• Resistant turfgrasses• ‘Floratam’ was once resistant – now a favorite in FL• ‘Captiva’ was only commercially produced resistant

cultivar• All other cultivars are susceptible to feeding &

damage• ‘CitraBlue’ is susceptible to feeding, but shows good

tolerance*

Rangasamy et al. 2006. Journal of Economic Entomology

Chinch bug management tips

• One female produces up to 200 eggs, egg to adult takes about 4 weeks = Rapid population growth

•Most active during dry, hot periods

• Insecticides kill nymphs and adults, but not the eggs

• Applying more nitrogen = more eggs being laid

• Thick thatch is a great habitat and the organic matter binds certain insecticides (e.g., pyrethroids)

• Insecticide resistance is real: ROTATE!!!

Resistance Management

- Pyrethroids (Group 3)- Bifenthrin, Beta-cyfluthrin, Deltamethrin, Lambda-cyhalothrin, Permethrin

- Neonicotinoids (Group 4A)- Clothianidin, Imidacloprid, Thiamethoxam

- Neonicotinoids + Pyrethroids (Group 4A + 3)- Triple Crown, Allectus

- Carbamates (Group 1A)- Carbaryl (Sevin)

- Anthranilic diamides (Group 28)- Chlorantraniliprole (Acelepryn)- Cyantraniliprole (Ference)

Chemical Control

Southern Chinch Bug Control

• Insecticide programsExisting outbreak:1. Bifenthrin (Pyrethroid)2. Clothianidin (Neonicotinoid)3. Carbaryl (Carbamate)4. Chlothianidin/Cyantraniliprole

(Diamides)OR

1. Pyrethroid + Neonic (combo)2. Carbaryl (Carbamate)3. Options

Pre-outbreak:1. Clothianidin (Neonicotinoid)2. Bifenthrin (Pyrethroid)3. Carbaryl (Carbamate)4. Chlothianidin/Cyantraniliprole

(Diamides)OR

1. Clothianidin2. Options

Resistance Management

Mole Crickets (Orthoptera: Gryllotalpidae)

• Three damaging invasive species• Tawny mole cricket• Southern mole cricket• Short-winged mole cricket

• One native species• Northern mole cricket

Tawny Mole Cricket (Neoscapteriscusvicinus)

• Feed on roots at night

• Adult males call females for 1 hr after sunset

• Egg laying: March – June

• Females make 3-5 egg chambers, each with ~40 eggs

• Eggs hatch in ~3 weeks

• Nymphs feed through summer, most are adults by October

Photos by L. J. Buss, UF/IFAS

Southern Mole Cricket (Neoscapteriscusborellii)

• Omnivorous

• Adult males call females for 1 hr after sunset

• Egg laying: May – July

• Eggs hatch in ~3-4 weeks

• Nymphs develop slowly; most overwinter as nymphs

Photos by L. J. Buss, UF/IFAS

Mole CricketsHow do you monitor for them?

Mole CricketsHow do you monitor for them?• Proper timing

• Monitor when nymphs are hatching & becoming active

• Soapy water flush – 1-2 TBSP lemon scented Joy with 1 gallon of water

• Attracted to bright lights• Prefer moist soils

Walker, T. Genus Neoscapteriscus. University of Florida.

Mole Crickets

• Males call for females from within their burrows• Females fly in to mate and lay eggs underground in

the tunnels• One male may attract dozens of females

Brandenburg et al. 2002. Florida Entomologist

Egg Laying and Hatching• Mated females fly (at night) to find a place to lay

their eggs• Eggs mature inside the female for 9-14 days

before being laid• 25-60 (ave. = 40) gray/brown eggs are laid in a

small chamber in the soil, 3-12 in deep• Eggs develop in soil in approximately 20 days

Mole Cricket Management• All turfgrass species are vulnerable to attack• Low-cut, sports and golf turf often require chemical control

• Nocturnal, so early morning or evening monitoring will be most successful

• Young nymphs are easier to kill than older nymphs and adults (preventive vs. curative)

• Keep lights off at night, low-lying areas are hot spots

Kerr et al. 2014. UF/IFAS EDIS #IPM-206

Tropical sod webworm

Caterpillars

• Young larvae scrape the leaf surface (window-feed).

• Damage may go unnoticed but close inspection finds small (2 - 3 foot diameter) grayish areas.

• Large larvae notch or consume the grass blades, which gives the grass a ragged appearance.

• Larvae of several moth species may feed together.

Tropical Sod Webworm(Herpetogramma phaeopteralis)

• Eggs are very small and deposited in clusters on the surface of leaf blades

• Hatch in ~4 days• Larvae (caterpillars) feed on leaf surfaces at first and

begin to consume entire leaves as they age• Feed as larvae for approx. 3 – 4 weeks during summer

and up to 47 days during cooler months

Fall Armyworm

• Eggs are laid in masses of 100-200 hundred

• Typically on white/light colored surfaces near turf or underside of ornamental plant leaves

• One female will lay 1500 – 2000 eggs• Eggs hatch in 2 – 3 days during

summer months

Fall Armyworm

• Larvae had a distinctive inverted ‘Y’ on their head• Larvae feed for 2 – 3 weeks during summer months

and 4 – 5 weeks during cooler months• Typically damaging by July/Aug and may last

through Oct/Nov • Established, healthy grass can tolerate damage but

newly laid sod or plugs can be killed

Tropical Sod Webworm(Herpetogramma phaeopteralis)

• Larvae pupate on or beneath the soil in a cocoon of silk, frass, and grass

• Pupate for approx. 1 week

Caterpillar IPM in Turf

Cultural control:• Minimize thatch and use BMP recommendations for

mowing, irrigating, and fertilizing turf• ‘Cavalier’ zoysiagrass is only resistant warm season turf

Biological control:• Entomopathogenic nematodes, especially Steinernemacarpocapsae

• Parasitoids, generalist predators, and birds are active predators

Mechanical control:• If moths are flying - Collect and discard turf clippings

Forms of Intervention in IPM

Incorporate as much of 1-3 as possible and #4 appropriately1. Cultural practices2. Mechanical control3. Biological control4. Chemical control Immediate / short-term solutions

Longer-term solutions

Biological Control as an IPM Tactic

1. Classical biological control• Several years of research identifying predators & parasites

in native land• evaluating predators & parasites for safety in new land• releasing viable agents in new land & evaluating success

2. Augmentative biological control• Collecting or purchasing predators and parasites and

releasing them on location to enhance existing biological control

3. Conservation biological control• Using cultural and chemical practices that attract or

promote existing biological control

Conservation biological control

Promoting the natural regulation of plant pests with proper pesticide use

Avoid repeat broad-spectrum insecticide apps & use insecticides or application techniques with selectivity for pests, when possible• Toxic effects on every arthropod encountered • Beneficials are typically most affected• Products applied into soil can reduce exposure to non-targets

above-ground• Systemic products can reduce non-target exposure

Newest Tool for Caterpillar Control

Active ingredient - Chlorantraniliprole• Acelepryn (commercial)• GrubEx (homeowner)• minimally toxic to predatory beetles and

bumble bees• Excellent residual activity• Highly effective against caterpillars and

beetles

Insecticide Control of Caterpillar Pests

• Treated lawns with:• Bifenthrin (Talstar) – 8 oz/100 gal• Clothianidin (Arena) – 9 oz/100 gal• Chlorantraniliprole (Acelepryn) - 2 oz/100 gal

• Introduced sod webworm caterpillars to treated areas weekly for 5 weeks

Tofangsazi et al. 2014

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Insecticide Control of Caterpillar Pests

Tofangsazi et al. 2015

• Chlorantraniliprole did not reduce # of natural enemies or soil-dwelling arthropods

• Clothianidin and bifenthrin did

1. Cultural Control Tactics

Long-term, sustainable pest management strategies for reducing pests and promoting plant / ecosystem health

Habitat manipulation through: a. Host plant resistanceb. Landscape design & plant selectionc. Increasing plant and wildlife biodiversity

Rangasamy et al. 2006. Journal of Economic Entomology

Cultivar Development

New cultivar available :• ‘CitraBlue’ St. Augustinegrass

• Excellent drought tolerance• Improved resistance to gray leaf spot, large patch, &

take-all root rot• Improved shade tolerance• Increased density compared to Floratam• Moderate chinch bug tolerance

Conservation biological control

Promoting the natural regulation of plant pests with proper plant selection and habitat management

Have plant material nearby that attracts and supports beneficial insects • Several different plant species • Flowering plants

Provide habitat conducive to beneficial insect nesting and reproduction• Pollinator nesting boxes• Areas of low management

High diversity

Low diversity

Pollinator gardens and conservation plantings are a great addition to any landscape

Pollinators do more than pollinate

Lyle Buss

Portman et al. 2010Rogers & Potter 2004

Southern & tawny mole cricketSpermacoce verticillataLarra wasp (Larra bicolor)

Tiphiid & Scoliid wasps

White grubs

Credit: Cynthia AbbottCredit: John Lampkin

Red and black mason wasp

Beneficial Insect Surveys

• >3X as many native bees in high diversity wildflower plots

• 5X as many flying predatory insects in high diversity wildflower plots

Credit: John Lampkin

Floral abundance & richness increased biological control

Dale et al. 2019. Urban Ecosystems

Disappearance rates of fall armyworm increased by nearly 50% adjacent to wildflower plots• Floral richness

mattered• No effect of

distance from plot edge up to 18m

F2,138 = 6.02, P=0.0031 F2,138 = 8.23, P=0.0004

Recent publications on conservation

biological control in the landscape

What factors in urban landscapes affect insect plant pests?

• Plant stress• Plant selection• Habitat disturbance• Microclimate conditions• Presence/absence of natural enemies• Plant diversity & the abundance of host plants

Increasing St. Augustinegrass Diversity

Six St. Augustinegrass cultivarsA. FloratamB. PalmettoC. BitterblueD. ClassicE. SevilleF. Captiva

Doherty et al. 2019. Environ Entomol

Summary

Mixing St. Augustinegrass cultivars affects herbivore body size, larval host choice, and herbivory

Seem to be cultivar-dependent effects within mixtures• Pairs that included ‘Classic’ had the lowest larval weights (No-

choice)• ‘Bitterblue’-’Floratam’ had the lowest survival rate (Limited-

choice)• ‘Floratam’-’Palmetto’ and ‘Classic’-’Floratam’ had the least

herbivory (Limited-choice)

<- Mix of 2

<- Mix of 4

<- Single cultivar

Southern chinch bugBlissus insularis (Hemiptera: Blissidae)

Photos: Matt Borden

Most economically important insect pest of St. Augustinegrassin the southern U.S.• Estimated $20 million annual impact

• Documented resistance to multiple insecticide classes

• No commercially-available resistantcultivars

• Limited IPM tactics

Southern chinch bug surveys: 2018

• Vacuum sampled each plot to quantify SCB abundance

Southern Chinch Bug Abundance

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July 2018 September 2018

Model: F4,58=3.67, P=0.0099# of Cultivars: F=3.21, P=0.0475

TRT Tukey

M1 A

M2 AB

M4 B

• 2018 data indicate effects on southern chinch bug populations

• Currently processing 2019 data

Evaluating turfgrass industry viability

1.High-resolution density and greenness2.Aerial NDVI, density, and greenness3.Industry surveys

Even if there is pest control value, it won’t be used if it doesn’t look good or perform well

Objective Turf Quality

• Light box image analysis on 23 dates from May 2017 until December 2019 detect benefits of cultivar mixtures

Industry perceptionSurveyed industry professionals in 2017 (n=83) and 2019 (n=100)• No prior knowledge of experiment or plot treatments• Scale of 1 – 9, how good does each plot look?

October 2017 October 2019

2017 2019

SummaryA plausible IPM strategy for sod production & residential lawns

• Indications of insect pest management benefits• Increased plant density and greenness• Industry acceptance

Working towards more sustainable urban landscapes

Ongoing work

Regional effects and cultivar mixture recommendations

Summary• Knowing pest biology and seasonality is critical • Insecticide selection determines compatibility

with beneficial organisms and long-term pest control efficacy

• Successful IPM relies on good cultural practices• Manipulating plant diversity and traits can reduce

pests• Greater plant diversity conserves more wildlife &

increases resilience to pests and abiotic stress!

Think about what benefits your lawn is providing in the context of pest management and conservation

5 weed species intermixed with St. Augustinegrass – what are the tradeoffs?

• For updates on landscape insects:

• @adamGdale• http://dalelab.org• agdale@ufl.edu• Blogs.ifas.ufl.edu

Recent EDIS publications:• Natural products for managing insects on landscape plants• Managing insecticide and miticide resistance on landscape plants• Managing crapemyrtle bark scale• Managing southern chinch bugs in Florida lawns• Stinging and urticating caterpillars of Florida• Managing bermudagrass mite

http://ifasbooks.ifas.ufl.edu/p-153-helpful-harmful-harmless.aspxUF/IFAS Extension Bookstore:

Acknowledgements:• UF/IFAS • FNGLA• TPF• Syngenta• On Top of the World• Mark Bostick Golf

Course• USDA-NIFA

Thank you!