Insect Growth Regulators –Discovery, Development &

How They Work

Dr. Bill DonahueSierra Research Laboratories

www.sierraresearchlaboratories.com

2015 CAPCA Conference & Agri-Expo

Reno, NV

October 20, 2015

The Modern Environmental Movement

“Not war, but a plethora of man-made things…is threatening to strangle us, suffocate us, bury us, in the debris and by-products of our technologically inventive and irresponsible age.” Margaret Mead – Cultural Anthropologist

The Way It Was

DDT was hailed as “the miracle insecticide” and “almost perfect control

product for this pest [bed bugs]” Resistance was observed

after only 5 years of use.

NEW INSECT CONTROL STRATEGY

Reduce Reproductive Potential

Breaking the Life Cycle

Target most Vulnerable Life Stage

Least Toxic Approach – Chemical, Mechanical, Cultural Control Techniques - IPM

IGR’s - A Historical Perspective

Sir Vincent Wigglesworth (1899-1994) – Insect endocrinology Rhodnius - corpora allata maintaining the larval status quo and the molting hormone – ecdysis – Text Books Insect Physiology (1934), Insect Hormones (1970)

IGR’s - A Historical Perspective

Herbert Roller (U. of Wisconsin & Texas A&M) –1967 identification of JH 1

Zoecon – 1968 JH 2, JH 3 & JH 0 – JH analogs methoprene EPA registered in 1975

Carl Djerassi

IGR’s - A Historical Perspective

Duphar B.V. (Netherlands) – Diflubenzuron(Dimilin) first CSI to be discovered van Daalen et. al. - 1972

Insect Brain & Hormones

Juvenile Hormone Mimics

The primary mode of action is the prolongation of the immature stage of the insect so that it does not become a reproductive adult.

Examples: methoprene, hydroprene, fenoxycarb and pyriproxyfen

Chitin Synthesis Inhibitors

The primary mode of action expressed is the immature insects inability to molt due to inhibition of the synthesis of a new cuticle.

Examples: diflubenzuron, cyromazine, lufenuron and novaluron.

Cockroach Control – IGR Only: (S)-hydroprene

Bastrop Study – Solving a Tough Problem – PCT August 1989

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Gencor® IGR

Percentage of Cockroach Reduction Over Time

COMPONENTS OF AN IPM PROGRAM

Natural Control – Use or Enhance What’s There, Biological Control – Parasites, Predators and Pathogens

Cultural Control – Modify Existing Practices such as Temperature, Watering, Fertilizing

Mechanical/Physical Control – Specialized Equipment or Practices Such as Mowing and Tilling

Chemical Control – Many Choices – Least Toxic Approach!

Urban Pests on IGR Product Labels

Mosquitoes – many species

Stored Product Pests

Flies – house flies, horn flies, drain flies, fungus gnats

Fleas – primarily the cat flea

Cockroaches – primarily German cockroaches

Ants – Pharaoh, red imported fire ant

Bed bugs

Ticks

Evaluation for Ovicidal Potential of Insect Growth Regulators Against Bed Bugs “Earl”

IGRs tested:•(RS)-Methoprene•(S)-Hydroprene•Pyriproxifen•Cyromazine•Fenoxycarb

•Approximately 1 mL applied to 7.5 cm filter paper circle (label rate)•Each filter paper contained 10-20 eggs, aged <24 hours prior to treatment•Scored daily until 3 days past total control group hatch

© Sierra Research Laboratories, 2010

© Sierra Research Laboratories, 2010

© Sierra Research Laboratories, 2010

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Day 15

Hatch Rates of "Earl" Strain Bed Bug Eggs 15 Days Post-Treatment of

Various IGRs

Untreated Control

H2O Control

(RS)-Methoprene

(S)-Hydroprene

Pyriproxifen

Cyromazine

Fenoxycarb

Placebo

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Average Percentage of 1st Instars Molting to 2nd Instars Post-Feeding

Time Post-

Feeding

Untreated Control

H2O Control

(RS)-Methoprene

(S)-Hydroprene

Pyriproxifen Placebo Cyromazine Fenoxycarb

5 days 92.7% 95.4% 92.4% 89.6% 90.8% 61.8% 89.9% 90.9%

© Sierra Research Laboratories, 2010

2014 Tests with Novaluron + Pyriproxyfen (TEKKO Pro®Showed no reproductive effects

to mated adult females or theiroffspring. BD Unpublished

Mosquito Drum Test Evaluating Novaluron (EcoSafe® G) at Two Ratesagainst Yellow Fever and Asian Tiger Mosquitoes

Water draw-down (15 gal) day 1 and 2, refill day 3 repeat for 13 weeks.Water samples taken for chemical analysis and efficacy 0, 2, 4, 8, 10, 13 weeks.

TestGroup

Species Week 0 Week 2 Week 4 Week 8 Week 10 Week 13

Controls YFM 96.9 100 96.8 98.0 95.4 98.2

EcoSafe® 0.2X

YFM 7.1 44.4 15.5 0 1.2 5.9

EcoSafe® 1X

YFM 0 0 0 0 0 0

Controls ATM 99.6 98.8 96.1 98.8 97.3 97.6

EcoSafe® 0.2X

ATM 15.7 57.3 27.0 0.8 2.4 0.7

EcoSafe® 1X

ATM 0 0 0 0 0 0

Results: Average % Adult Mosquito Emergence (n=10)

Conclusions: 100% mortality of emerging mosquitoes > 13 Weeks at label rate, not as good at 1/5 rate. Safe and Effective to use in drinking water.

New Mosquito IGR Product Research

Laboratory and Field Evaluations of Mosquiron 0.12CRD , a New Formulation of Novaluron, Against Culex Mosquitoes. Tianyun, S.U., et. al., J of AMCA, 2014 – EPA Registered briquet formulation not in CA

90-99% effective for up to 35 days in storm drains against Culex Mosquitoes – Ontario, CA – Calif. Research Authorization

Truck-Mounted Area-Wide Application of Pyriproxyfen Targeting Aedes aegypti and Aedes albopictus in Northeast Florida. Doud, C.W., et.al. J of AMCA, 2014 – Not EPA Registered – EUP

84-92% Inhibition of Adult Emergence from 3 different distances 8-23 meters – Ae. aegypti

~50% fewer adult Ae. albopictus captured in area traps after 2-3 sprayings

ULV Applications

New Fly IGR Product ResearchNovaluron Granules and EC compared with Neporex Granules on Caged LayerOperations in California

Novaluron Evaluations on Dairiesand a Horse Ranch

A Point to Ponder

A pair of flies beginning operations in April may be the progenerators, if all were to live, of 191,010,000,000,000,000,000flies by August. Enough to cover the earth 2.5 feet deep. Hodge (1911)

Applications

Collect Manure Samples Weekly for 4 weeksBring back to the Lab

Dairy Cows

Horse Stalls

Poultry Barns

6 Reps + sub-reps

Set-up Cup Bioassays

50 fly eggs – house and stable fly

Score 3 - 4 weeks – Adult Emergence

Samples from each Farm

Natural Fly Populations

Adult Fly Emergence

Predators, Parasites & Pathogens

Adult Fly Counts – Lots of Fly Counts!

IGR Effects – Molting & Metamorphosis

Dairy – Neporex (Cyromazine) Lab and Field Study Results

Novaluron EC and Granules applied to cattle, horse and chicken manure incommercial farming operations provided a high degree of inhibition (≥90%)of adult house fly and stable fly development for up to 4 weeks undercommercial production conditions in central California.

Conclusions

Manure management (cultural control) is an important component encompassing an IPM control strategy. IGRs such as Novaluaronshould also be considered in a rotational chemical control program todelay the onset and severity of insecticide resistance in fly populations.

However!

New Tick IGR Product Research

Humans – Animals - Environment

Pyriproxyfen affects moltingEgg Production and HatchIntermediary Metabolismof the Lone Star Tick –

Donahue, Teel, Meola & Strey TAMU

J Med Entomology 1996 & 1997

Pryiproxyfen + Novaluron? The Research Continues!

Results

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Larva Nymph

Average Percent of Amblyomma americanum molting (n=10)

Water Control - Run 1

Water Control - Run 2

Pyriproxyfen + Novaluron- 4µg/cm2

Pyriproxyfen + Novaluron- 8µg/cm2

Points to Ponder

IGR Control Strategy – Breaking the Life Cycle

Insect Physiology Pioneers – Science Continues

Molting and Metamorphosis – Key for Insects

Urban Pests Controlled by IGRs – Safe & Effective

IGR Product Development Continues…

Questions?bill@sierraresearchlaboratories.com