Transcript Locust mobile

Pest, Plagues & Politics
Lecture 18
Locust Plagues
Key Points:
Locust Plagues
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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
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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