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PESTICIDES
PESTICIDES
• ANYTHING USED TO CONTROL “PEST” POPULATIONS
• BROADLY CATEGORIZED BY TARGET GROUP
• HERBICIDES – WEEDS
• INSECTICIDES – INSECTS
• RODENTICIDES – RODENTS
• FUNGICIDES - FUNGUS
COMPARING PESTICIDES
FIRST GENERATION PESTICIDES
• ALL NATURAL
• 1400’S - HEAVY METALS
USED
• 1800S – PYRETHRUM ,
NICOTINE, AND ROTENONE
SECOND GENERATION PESTICIDES
• 1940 AND BEYOND
• MUCH MORE POTENT THAN FIRST GENERATION
• MAN-MADE (SYNTHETIC)
CLASSES OF PESTICIDES
• CLASSIFIED BY CHEMICAL STRUCTURE (ALL HAVE SIMILAR
STABILITY, SOLUBILITY, MOBILITY, AND TOXICOLOGY)
INORGANIC PESTICIDES
• ARSENIC, SULFUR, COPPER, LEAD, MERCURY
• NATURALLY OCCURRING IN ENVIRONMENT
• HIGHLY TOXIC AND ALMOST INDESTRUCTIBLE
• VERY LONG PERSISTENCE
• GENERALLY NEUROTOXINS
NATURAL ORGANIC PESTICIDES
• BOTANICALS (PLANTS)
• INCLUDES: ALL TOXIC TO INSECTS BUT OTHER GROUPS AFFECTED ARE:
• NICOTINE – TOXIC TO MANY ORGANISMS INCLUDING HUMANS
• ROTENONE –FISH
• PYRETHRUM –APHIDS, TICKS, ETC.
CHLORINATED HYDROCARBONS
• SYNTHETIC ORGANIC INSECTICIDES THAT INHIBIT NERVE SIGNALS
• FAST ACTING, HIGHLY TOXIC IN SENSITIVE ORGANISMS
• PERSISTENT FOR DECADES
• BIOMAGNIFY
• INCLUDE DDT, CHLORDANE, ALDRIN, DIELDRIN, TOXAPHENE, MOTHBALLS, LINDANE
• MANY HAVE BEEN BANNED FROM WORLDWIDE USE DUE TO HEALTH HAZARDS
• ACT AS A HORMONE DISRUPTOR (BALD EAGLES)
ORGANOPHOSPHATES
• DEVELOPED FROM NERVE GAS RESEARCH IN WWII
• EXAMPLES INCLUDE: PARATHION, MALATHION, DICHLORVOS, DDVP, AND TEPP
• INHIBIT NEUROTRANSMISSION
• MUCH LESS PERSISTENT BECAUSE THEY ARE QUICKLY DEGRADED BUT EXTREMELY TOXIC TO BIRDS, FISH, AND MAMMALS
CARBAMATES
• SIMILAR TO ORGANOPHOSPHATES
• TARGET BEE POPULATIONS UNINTENTIONALLY
• EXAMPLES INCLUDE CARBARYL, ALDICARB,
AMINOCARB, CARBOFURAN, AND MIREX
THE NEW DDT??
• HALOGENATED PYRROLES
• NEW CLASS OF COMPOUNDS BASED ON A
NATURALLY OCCURRING MICROBIAL TOXIN
• USED TO REPLACE ORGANOPHOSPHATES
• HAS SHOWN ENDOCRINE DISRUPTION IN
BIRD POPULATIONS
BIOPESTICIDES
• ORGANISMS OR TOXINS DERIVED FROM THEM USED IN THE PLACE OF PESTICIDES
• FOR EXAMPLE – BACILLUS THURINGIENSIS OR BACILLIS POPILLIAE KILL CATERPILLARS AND BEETLES BECAUSE THEY PRODUCE A TOXIN THE DESTROYS THEIR DIGESTIVE TRACT
• VIRAL DISEASES HAVE ALSO BEEN USED AGAINST SPECIFIC PESTS
PESTICIDE RESISTANCE
• MOST NEVER REACH THEIR INTENDED TARGET
• ALSO NEVER KILL 100% OF THE INTENDED SPECIES EVEN
UNDER THE BEST CONDITIONS
• CAUSES PEST RESURGENCE (REBOUND) – SURVIVING
MEMBERS REBUILD A RESISTANT POPULATION
• PESTICIDE TREADMILL
• BASED ON PEST RESURGENCE
• FARMERS HAVE TO APPLY MORE PESTICIDES TO HAVE DESIRED EFFECT
PESTICIDE REGULATION IN THE US
• FIFRA – FEDERAL INSECTICIDE, FUNGICIDE, AND RODENTICIDE ACT
• ALL COMMERCIAL PESTICIDES MUST BE APPROVED BY THE EPA FOR
GENERAL OR RESTRICTED USE
• THE EPA SETS A TOLERANCE LEVEL SPECIFYING THE AMOUNT OF THE
PESTICIDE THAT CAN REMAIN ON THE PRODUCT WHEN IT IS EATEN
(FRUITS AND VEGGIES)
FQPA – FOOD QUALITY PROTECTION ACT
• REQUIRES
• NEW STANDARDS FOR PESTICIDE TOLERANCE LEVELS IN
FOOD
• ACTIVE INGREDIENTS ARE SAFE FOR INFANTS AND CHILDREN
• EPA HAS TO CONSIDER SYNERGISTIC EFFECTS WHEN SETTING
TOLERANCE LEVELS
UNION CARBIDE/ BHOPAL, INDIA DISASTER
• BHOPAL FACILITY WAS PART OF INDIA’S GREEN REVOLUTION TO
PRODUCE/STORE PESTICIDES – PRODUCED METHYL ISOCYANATE
(MIC) (TOXIC GAS USED TO MAKE PESTICIDES)
• LARGEST INDUSTRIAL DISASTER IN HISTORY (1984) – WATER GOT
INTO AN MIC STORAGE CONTAINER
• 40 TONS OF MIC ESCAPED
• HUNDREDS OF THOUSANDS WERE AFFECTED (RESPIRATORY
AGGRAVATION) AND UP TO 4,000 KILLED
OTHER WAYS TO CONTROL PESTS
• WHAT IS THE REAL GOAL OF PEST CONTROL?
• GOAL SHOULD BE TO REDUCE CROP DAMAGE TO AN
ECONOMICALLY TOLERABLE LEVEL
INTEGRATED PEST MANAGEMENT
• OVERALL GOAL IS NOT TO ERADICATE PEST POPULATIONS BUT
TO REDUCE CROP DAMAGE TO AN ECONOMICALLY TOLERABLE
LEVEL
• LOOK AT ALL ASPECTS OF MANAGING PESTS –
BIOLOGICAL, CHEMICAL, COSTS, ETC.
HOW CAN CULTIVATION HELP PEST CONTROL?
• CROP ROTATION
• PLANT HEDGES AND TREES AROUND FIELDS TO MAKE HABITATS FOR NATURAL ENEMIES
• USE VACUUM MACHINES TO REMOVE BUGS
NATURAL ENEMIES
• USE OF PREDATORS, PATHOGENS, AND PARASITES TO CONTROL PESTS
• PROS
• FOCUSES OF TARGET SPECIES AND IS NONTOXIC TO OTHER SPECIES
• CONS
• CANNOT BE MASS PRODUCED; CAN ATTACK DESIRABLE INSECTS; SLOWER ACTING
PHEROMONES
• GOOD B/C
• IT TARGETS ONE SPECIES
• WORKS IN TRACE AMOUNTS
• LITTLE CHANCE OF GENETIC RESISTANCE
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