11 threat to biodiversity Flashcards
what are the most widely used pesticides in the prairies?
typically, what are the most troublesome pesticides?
insecticides
-5 major classes
what are the five major classes of insecticides?
-organochlorines: DDT, dieldrin
-organophosphates: monochrotophos, malathion, chlorypyrifos
-carbamate: carbofuran, carbanyl
-pyrethroids: permethrin, deltamethrin
-neonicotinoids: imidacloprid, clothanidin, thiamethoxam
what are organochlorines?
DDT, dieldrin
-chlorinated hydrocarbons
-1st synthetic chemical
-very persistent in environment
-bioaccumulates due to high fat solubility
what are organophosphates?
monochrotophos, malathion, chlorypyrifos
-very diverse and most widely used
-fast acting on acetylcholinesterase enzyme
-short half life
-long term health effects and developmental effects
what are carbamates?
carbofuran, carbanyl
-mechanism similar to organophosphates
-extremely toxic to birds but reversible toxicity (binding) to mammals
what are pyrethroids?
permethrin, deltamethrin
-synthetic derived from pyrethrin (a natural compound from chrysanthemum flowers)
->1000 compounds with highly variable toxicity
what are neonicotinoids?
imidacloprid, clothanidin, thiamethoxam
-derived from nicotine
-commonly used as seed treatments
-water soluble and persistent
what is the table of direct insecticide acute toxicity reference values for birds?
where is the neonicotinoid insecticide class found?
imidacioprid (admire), clothianidin, thiamethoxam, acetamiprid, thiacloprid, dinotefuran
-sold in 120 countries
-registered for use on 140 crops
->80% of global market share of seed treatments
->35% of the insecticide market
what have neonicotinoids caused?
-bee mortality, colony collapse disorder, sublethal effect studies
-contaminate whole ecosystems
-prevalent in aquatic environment
what is the graph of neonicotinoids in wetlands?
we found neonicotinoids in wetlands surrounded by all crop types: wetlands sampled in barley, canola, and oat fields all higher than in grasslands
what is the graph of aquatic sensitivities to neonicotinoids?
are highly toxic to aquatic invertebrates but with wide range of sensitivity
what is the worldwide exceedances of neonicotinoids?
worldwide exceedance of acute and chronic threshold concentrations that affect aquatic insects in surface waters
what is the graph of pesticide contamination of prairie wetlands?
what are the pesticides detected in prairie wetlands?
what are some good news about wetlands?
intact wetlands can ameliorate pesticide contamination
what is the neonicotinoid exposure pathways in songbirds?
what are research methods of seed-eating birds?
what is the difference of mammals and bird events from camera traps?
what were the observed events in mammalian species?
what were the observed events in avian species?
what are red winged blackbirds an example of?
-red winged blackbirds exposed to neonicotinoids or food restricted, change in body mass in 24 hours
what can imidacloprid caused?
causes birds to lose appetite and lose body mass
can these insecticides affect songbird migratory ability?
-exposure to imidacloprid (but not chlorpyrifos) caused significant decrease in WCSP body mass and loss of migratory orientation
what would happen to free living birds if they eat a few treated seeds?
-no effect on flight direction and speed
-but migration departure is delayed
how many seeds would it take to cause this?
what is the summary of research on neonicotinoids in the prairies?
what is the debate with neonicotinoids?
what is the current situation on neonicotinoids?
what is not the solution?
single pesticide bans
