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Pest, Plagues & Politics Lecture 18

Locust Plagues

Key Points:

Locust Plagues • • • • •

Historical perspective European/African Locusts American Locusts Grasshopper VS locust Development of controls

“They

have left my fig trees broken; The fields are ruined; Despair you farmers; Like a blackness spread upon the mountains a great and powerful army comes.”

Joel, chapter 1

For your interest http://www.roundtree7.com/2012/04/alberts-swarm/

A thing of the past?? • 2002-12 – Locust Plagues – – – – – –

Afghanistan Kazakhstan China Chad Australia Grasshopper problems in mid-western U.S.

http://www.google.com/hostednews/afp/article/ALeqM5gbDXumh4HxdqmV QyWMmdt-z8k6mw?docId=CNG.a7f5868b3661b5beedfbba67acac7c9c.5b1

For your interest

For your interest

A thing of the past??

http://en.tengrinews.kz/kazakhstan_news/Tajik-locusts-threaten-Kazakhstan-crops-2463/

West Wind

East Wind

For your interest

http://www.sciencedirect.com/science/article/pii/S002219101 0001460

Grasshopper Glacier located 70 miles southwest of Billings, MT http://formontana.net/grasshopper.html For your interest

Locust in Oregon??? {absolutely} • For many thousands of years before there was a “political” Oregon. • Melanoplus spretus - the Rocky Mt. Locust • Now extinct!! – Evidence of locust swarms found in Wyoming glacial deposits which are 840 ± 85 yrs B.P. – Locust remains in layers measured in feet!! For your interest

For your interest

1874 Rocky Mt. Locust “Plague”

http://wyofile.com/2010/11/3507/

Another flick from 1975 But “locusts” are only a metaphor

For your interest

Locust Philately

For your interest

Here she is: Schistocerca gregaria The infamous Desert Locust

For your interest

Orthoptera Taxonomy or what’s the dif. Between a grasshopper and a locust

• Order Orthoptera (straight wing) – 30,000 species – includes the grasshoppers, locusts, katydids & crickets – family: Acrididae (most grasshoppers & locust) • 8,000 species worldwide with only a FEW as pests

• A locust is a MIGRATORY & GREGARIOUS grasshopper.

Locust • Notorious creatures with a long history of human interactions – One of the putative biblical plagues – Biblical references: • 10 for grasshoppers • 24 for locusts

– Ergo, these insects were very familiar to ancient civilizations.

For your interest

Grasshoppers & Locust • Univoltine • Hemimetabolous (incomplete metamorphosis) – egg; nymph (normally 5 nymphal stages) - adult

• Over-winter in the egg stage • Locusts are found on every continent (well, with the exception of Antarctica)

Melanoplus devastator - the devastating grasshopper

*Grasshopper to Locust Transition Solitary

grading to

Migratory

Lighter in color

Darker in color

Longer hind legs

Shorter hind legs

Shorter wings

Longer wings

Sedentary

Gregarious http://michaelscomments.wordpress.com/2009/0 9/19/cicadas-vs-periodic-cicadas-vsgrasshoppers-vs-locusts/

PNW Grasshopper/Locust Control Philosophy (ODA et alia) • Control programs began in the 1930ties – sodium arsenite (a dry bait) – sodium fluosilicate (as a wet bait) – nicotine sulfate • killed grasshoppers effictively as well as three applicators one day in the Ephrata area of Washington in 1939

• Post WWII into the early 1960ties – widespread use of CHs (dieldrin, aldrin, chlordane & heptachlor)

19th Century American control

Grasshopper/Locust Control Philosophy (ODA et alia)

• Era of CH use – standard rate of application was 1/2 oz. per acre mixed in 1 gal. of diesel oil – residual buildup a big problem in environmentally sensitive areas such as the Malheur Wildlife Refuge • 33,000 acres treated with dieldrin in 1962 against the clear-wing grasshopper (Camula pellucida)

For your interest

Grasshopper/Locust Control Philosophy (ODA et alia) • Mid-1960ties – A move away from chlorinated hydrocarbons to the “hot” organosphosphate materials. • e.g., malathion

– The inclusion of the carbamate family of insecticides • e.g. Sevin

Oregon Grasshopper Control History 1985 1986

Malheur

1989 1990 1992 1993

Lake Lake Harney Klamath

Baker, Malheur & Union

494,950 966,810

Malathion

12,800 11,230 25,640 11,300

Malathion Malathion Malathion Malathion

Malathion & Carbaryl

For your interest

Oregon Grasshopper Control History • 2008 – 1,130,000 acres considered infested at an economic level – Average infestation was 29 GH/sqy – Treatments used a 5% Sevin bait & Dimilin in environmental sensitive areas (Malheur)

For your interest

Oregon Grasshopper Control History - Conclusions • Reliance on one method of control – CHEMICAL • Control programs in northeast, south central and eastern Oregon – regions of lowest human density – agriculturally based regions

Wiser use of insecticides • Western range lands – 50 species of grasshoppers – Of which 9 cause 95% of the damage

• Economic thresholds – 8 to 40 hoppers per square yard

• Chemicals most frequently used: – Malathion – Penn-cap M – Sevin

• RAAT

*RAAT • Reduce Agent/Area Treatment • One-half of the normal insecticide dosage on one-half of the acreage.

Newer control methods • Bio-cides – Entomopathogenic agents – Nosema locusta • A microsporidian that targets Orthoptera

– Metarhizium anisopliae • A fungus that targets Orthoptera

Key Points:

Locust Plagues • • • • •

Historical perspective European/African Locusts American Locusts Grasshopper VS locust Development of controls