Pest, Plagues & Pest, Plagues & Politics Politics Lecture 18 Lecture 18 Locust Plagues Locust Plagues
Dec 24, 2015
Pest, Plagues & PoliticsPest, Plagues & PoliticsLecture 18Lecture 18
Locust PlaguesLocust 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;They have left my fig trees broken; The fields are ruined;The fields are ruined; Despair you farmers;Despair you farmers; Like a blackness spread upon the Like a blackness spread upon the
mountains a mountains a great and powerful great and powerful armyarmy comes. comes.””
Joel, chapter 1
http://www.roundtree7.com/2012/04/alberts-swarm/
A thing of the past??A thing of the past??
• 2002-12 – Locust Plagues2002-12 – Locust Plagues– AfghanistanAfghanistan– KazakhstanKazakhstan– ChinaChina– ChadChad– AustraliaAustralia– Grasshopper problems in mid-western U.S.Grasshopper problems in mid-western U.S.
http://www.google.com/hostednews/afp/article/ALeqM5gbDXumh4HxdqmVQyWMmdt-z8k6mw?docId=CNG.a7f5868b3661b5beedfbba67acac7c9c.5b1
A thing of the past??A thing of the past??
http://en.tengrinews.kz/kazakhstan_news/Tajik-locusts-threaten-Kazakhstan-crops-2463/
West Wind East Wind
http://www.sciencedirect.com/science/article/pii/S0022191010001460
Grasshopper Glacier located 70 miles southwest of Billings, MT
http://formontana.net/grasshopper.html
Locust in Oregon???Locust in Oregon???{absolutely}{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!!
1874 Rocky Mt. Locust 1874 Rocky Mt. Locust ““PlaguePlague””
http://wyofile.com/2010/11/3507/
Another flickAnother flickfrom 1975from 1975
But But ““locustslocusts”” are areonly a metaphoronly a metaphor
Locust Philately
Here she is: Schistocerca gregariaThe infamous Desert Locust
Orthoptera Taxonomyor 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.
LocustLocust
• 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.
Grasshoppers & LocustGrasshoppers & 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*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/2009/09/19/cicadas-vs-periodic-cicadas-vs-grasshoppers-vs-locusts/
PNW Grasshopper/Locust Control PNW Grasshopper/Locust Control Philosophy (ODA Philosophy (ODA et aliaet 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)
1919thth Century American control Century American control
Grasshopper/Locust Control Philosophy (ODA Grasshopper/Locust Control Philosophy (ODA et aliaet 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)
Grasshopper/Locust Control Grasshopper/Locust Control Philosophy (ODA Philosophy (ODA et aliaet 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 HistoryOregon Grasshopper Control History
1985 Malheur 494,950 Malathion 1986 Baker,
Malheur & Union
966,810 Malathion & Carbaryl
1989 Lake 12,800 Malathion 1990 Lake 11,230 Malathion 1992 Harney 25,640 Malathion 1993 Klamath 11,300 Malathion
Oregon Grasshopper Control HistoryOregon 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)
Oregon Grasshopper Control History Oregon Grasshopper Control History - Conclusions- 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 insecticidesWiser 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:– MalathionMalathion– Penn-cap MPenn-cap M– SevinSevin
• RAAT
*RAAT*RAAT
• RReduce AAgent/AArea TTreatment• One-half of the normal insecticide dosage
on one-half of the acreage.
Newer control methodsNewer control methods
• Bio-cides– Entomopathogenic agents– Nosema locustaNosema locusta
• A microsporidian that targets Orthoptera
– Metarhizium anisopliaeMetarhizium anisopliae• A fungus that targets Orthoptera
Key Points:
Locust Plagues
• Historical perspective
• European/African Locusts
• American Locusts
• Grasshopper VS locust
• Development of controls